Version 0.4.5.3 Smart Property Crowdsale Edition
- JR Willett (https://github.com/dacoinminster and jr DOT willett AT gmail DOT com)
- Maran Hidskes (https://github.com/maran)
- David Johnston (https://github.com/DavidJohnstonCEO)
- Ron Gross (https://github.com/ripper234?source=c)
- Marv Schneider (https://github.com/marv-engine)
With input by Peter Todd (https://github.com/petertodd)
We claim that the existing bitcoin network can be used as a protocol layer, on top of which new currency layers with new rules can be built without changing the foundation. We further claim that the new protocol layers described in this document:
- Will fix the two biggest barriers to widespread bitcoin adoption: instability and insecurity.
- Will financially benefit the entire bitcoin user community, including those who don’t use the new protocol layers.
- Will provide initial funds to hire developers to build software which implements the new protocol layers, and ongoing funds to pay for maintenance of this software.
- Will richly reward early adopters of the new protocol, in proportion to how successful it is.
Our claims are built on the following assumptions:
- Alternate block chains compete with bitcoins financially, confuse our message to the world, and dilute our efforts. These barriers interfere with the adoption momentum of bitcoin and the adoption momentum of alternate currencies as well, regardless of how well-conceived their rules may be.
- New protocol layers on top of the bitcoin protocol will increase bitcoin values, consolidate our message to the world, and concentrate our efforts, while still allowing individuals and groups to issue new currencies with experimental new rules. The success of any experimental currency protocol layer will enhance the value and success of the foundational bitcoin protocol.
- Getting consensus and widespread adoption from the bitcoin community is not needed to add protocol layers, since no changes to the foundational bitcoin protocol are required.
- Tiny bitcoin transactions can be encoded into the block chain to support and represent transactions in higher protocol layers.
- A protocol can pay for its own software development, “bootstrapping” itself into existence, utilizing a trusted entity to hold funds and hire developers.
- It is possible to create tools to allow end users to create currency protocol layers which have a stable value, pegged to an external currency or commodity. In this way, users of these currencies can own stabilized virtual currency tied to U.S. Dollars, Euros, ounces of gold, barrels of oil, etc.
- It is possible for users of these new currencies to exchange between currencies with each other using simple rules and no central exchange.
The proposed protocol layers can be visualized as follows, with arrows representing users exchanging between currencies:
Note that all transfers of value are still stored in the normal bitcoin block chain, but higher layers of the protocol assign additional meaning to some transactions.
- Version 0.1 (previously 0.5) released 6 Jan 2012 (No packet definitions, overly-complicated currency stabilization)
- Version 0.1.9 (previously 0.7) released 29 Jul 2013 (Preview of 0.2, but without revealing the Exodus Address)
- Version 0.2 (previously 1.0) released 31 Jul 2013 (Version used during the fund-raiser)
- Version 0.3 (previously 1.1) released 9 Sep 2013 (Smart Property + improvements for easier parsing & better escrow fund health)
- Version 0.3.5 (previously 1.2) released 11 Nov 2013 (Added "Pay Dividend" message, spending limits for savings wallets, contract-for-difference bets, and distributed e-commerce messages. Also added Zathras' new appendix (description of class B and class C methods of storing Mastercoin data).
- Version 0.4 released 15 Feb 2014 (defined transaction message fields in a separate section, specified 5 transactions for initial deployment, added transaction version, New/Update/Cancel for sell offers, corrected dust threshold value)
- Version 0.4.5 released 20 Feb 2014 (added smart property crowdsale, other improvements to future features)
- Version 0.4.5.1 released 3 Mar 2014 (clarified Sell MSC for Bitcoins behavior)
- Version 0.4.5.2 released 31 Mar 2014 (clarified details of smart property creation)
- Version 0.4.5.3 released 3 Apr 2014 (corrected details of smart property administration)
- Pre-github versions of this document (prior to version 0.3.5 / previously 1.2) can be found at https://sites.google.com/site/2ndbtcwpaper/
- The term M.A.S.T.E.R. is an acronym for "Metadata Archival of Standard Transaction Embedding Records"
- The term "Master Protocol" applies to the specification and the clients that implement its features.
- The term "MSC Protocol" is used as the abbreviation for "Master Protocol".
- The term "Mastercoins" applies to the digital tokens that access the features of the "Master Protocol" clients.
- The term "MSC" is used as the abbreviation for "Mastercoins".
The “Master Protocol” layer between the existing Bitcoin Protocol and users’ currencies is intended to be a base upon which anyone can build their own currency. The software implementing the Master Protocol will contain simple tools which will allow anyone to design and release their own currency with their own rules without doing any software development.
Perhaps you have heard of the “Genesis Block” which launched the Bitcoin protocol. The Master Protocol has a similar starting point in the block chain, called the “Exodus Address” - the bitcoin address from which the first Mastercoins were generated during the month of August 2013. The Exodus Address is: 1EXoDusjGwvnjZUyKkxZ4UHEf77z6A5S4P
Initial distribution of Mastercoins was essentially a kickstarter style period to provide funding to pay developers to write the software which fully implements the protocol. The distribution was very simple, and proceeded as follows:
- Anyone who sent bitcoins to the Exodus Address before August 31st, 2013 was recognized by the protocol as owning 100x that number of Mastercoins. For instance, if I sent 100 bitcoins to the Exodus Address before August 31st, my bitcoin address owns 10,000 Mastercoins after August 31st.
- Early buyers got additional Mastercoins. In order to encourage adoption momentum, buyers got an additional 10% bonus Mastercoins if they made their purchase a week before the deadline, 20% extra if they purchased two weeks early, and so on, including partial weeks. Thus, if I sent 100 bitcoins to the exodus address 1.5 weeks before August 31st, the protocol recognized my bitcoin address as owning 11,500 Mastercoins (10000 + 15% bonus).
- Attempts to send funds to the Exodus Address on or after September 1st 2013 (after block #255365) were not considered Mastercoin purchases, and were refunded to the sender.
In the event that a purchase had multiple inputs, the input address contributing the most funds was recognized as owning the Mastercoins.
Note that anyone who purchased Mastercoins also received the same number of “Test Mastercoins” which are being used for testing new features before they are available for use in the Mastercoin protocol.
Initially, the only valid Mastercoin transaction was a “simple send” (defined later in this document), but the additional features described in this document are being implemented, and can be used once they are fully tested.
- Generation Rate: For every 10 Mastercoins sold during the Exodus period, 1 additional “Dev MSC” was also generated, which are being awarded to the Exodus Address slowly over the years following the exodus period (these Dev MSC are interoperable and fungible with regular MSC). These Development Mastercoins will ensure that developers have a continuing incentive to maintain, improve and add features to the Master Protocol implementations desired by users. The Distribution of these Dev MSC is structured so that developers receive 50% of the Dev MSC by one year after the initial Exodus Address period closed (date the Exodus Address closed - August 31st 2013, although transactions up till block 255365 were still accepted to account for slower propegation of transactions still sent on the 31st of August), 75% by a year later, 87.5% by a year later, and so on:
- As dev MSC vest, 50% of them are sent out as bonuses to people who won Mastercoin bounties, in proportion to how much bounty money they won (bitcoins). The other 50% are used for expenses such as retention bonuses. Eventually, the Mastercoin Foundation will turn over all remaining funds to a distributed bounty system, with the Master Protocol paying its own bounties via a proof-of-stake voting system, and the Mastercoin Foundation will no longer need to administer any funds for the project.
Technical notes:
- Any Mastercoin implementation implementing Exodus balance must recalculate the Development Mastercoin amount on each new block found and use the block timestamp for y.
- When calculating the years since the Mastercoin sale we assume a year is 31556926 seconds.
- 1377993874 is the Unix timestamp used to define the end-date of Exodus and thus the start date for the Development Mastercoins vesting.
- Current implementations do not have Test MSC which vest alongside dev MSC, but such coins may be recognized at some point in the future if it is deemed desireable
Bitcoin has some little-known advanced features (such as scripting) which many people imagine will enable it to perform fancy new tricks someday. The Master Protocol uses exactly NONE of those advanced features, because support for them is not guaranteed in the future, and the Master Protocol doesn't need them to embed data in the block chain.
The Master Protocol was originally specified to embed data in the block chain using fake bitcoin addresses (Class A), but we've since come up with a more blockchain friendly method which embeds data in a bitcoin multi-signature transaction (Class B). Once bitcoin miners start supporting the new OP_RETURN opcode as part of version 0.9 of the Bitcoin reference client, Master Protocol will be able to use that opcode to make the Master Protocol data completely prune-able (Class C) see description here by Gavin Andresen here: https://bitcoinfoundation.org/blog/?p=290
Class C transactions are most preferred due to the Provably Prune-able Outputs avoiding issues of "bloat" and "pollution" of the block chain.
The technical details for both Class A and Class B transactions can be found in Appendix A.
Not every bitcoin wallet lets you choose which address bitcoins come from when you make a payment, and Mastercoin transactions must all come from the address which holds the Mastercoins. If a bitcoin wallet contains bitcoins stored in multiple addresses, the wallet must first consolidate the bitcoins by sending ALL of them to the address which is going to initiate a Mastercoin transaction. Then, any Mastercoin-related bitcoin transactions will be sent from that address. Of course, mastercoin wallets hide this complexity from the user.
Wallets which do not allow you to consolidate to one address and send from that address (such as online web wallet providers) will not work for Mastercoin unless they are modified to do so. For this reason, attempting to purchase Mastercoins from an online web wallet will likely result in the permanent loss of those Mastercoins.
Other than for these hosted wallets, a bitcoin address can also be treated as a Mastercoin address, capable of storing and using any Master Protocol currency.
Occasionally the bitcoin blockchain experiences a "reorg", when the current longest chain is replaced by another longer chain. Sometimes this results in recent transactions changing their order, or which transactions are included.
The Master Protocol depends heavily on the order in which transactions appear in the blockchain. Even transactions in the same block can have different meaning or validity depending on the order in which they are recorded. Consequently, wallets and other blockchain parsers which also parse Master Protocol transactions need to detect these reorganizations and reparse the affected blocks, changing Master Protocol balances according to the the new ordering of transactions.
Initially, a reorganization could trigger a "naive" reparse, starting from the beginning and parsing all transactions in the history of the Master Protocol. Eventually, parsers should become more sophisticated and should keep checkpoints with all relevant Master Protocol Data written to disk at block milestones, so that they can start from the most recent unaffected checkpoint when a reorg event is detected.
The most important thing is that reorgs ARE detected. If an implementation does not contain code to react to reorgs, it could lose consensus with the other implementations, effectively forking the Master Protocol until the problem is noticed and the affected implementation is manually reset.
Also, in many cases a user may wish to do something with Mastercoins recently sent to them or otherwise affected by a recent transaction. Where possible, Mastercoin-aware wallets should re-use bitcoins from the previous transactions in subsequent transactions which are dependent on the earlier transactions. In this way, if the earlier transaction is invalidated (by a reorg), the dependent transaction will also be invalidated.
Not all features described in this document are active by default. Each feature will be unlocked on a certain block once it's deemed stable. Only Test Mastercoin transactions will be allowed if a feature is not unlocked yet. All other messages will be invalidated. The only exception to this rule is the Simple Send message, this has been enabled since Exodus.
- Mastercoin/bitcoin distributed exchange features are unlocked as of block #290630
- Smart property features are unlocked as of block # (TBD)
- Savings wallets and rate-limited wallets are unlocked as of block # (TBD)
- Data feeds and simple betting are unlocked as of block # (TBD)
- Contract-for-difference bets are unlocked as of block # (TBD)
- Distributed e-commerce features are unlocked as of block # (TBD)
- Escrow-backed currencies are unlocked as of block # (TBD)
Occasionally it seems prudent to change the format or interpretation of a Master Protocol message in order to improve the feature or fix a bug. To that end, each message has a version number. All Master Protocol implementations are expected to keep pace with changes of this nature, but in the event one falls behind, it must treat addresses which broadcast messages using version numbers it does not recognize as "black holes". That is, any funds or properties which enter the control of that address are considered lost and unspendable, since that address is using a newer version of the Master Protocol. In the event that the out-dated implementation is upgraded to recognize the new message formats, the blockchain can be re-parsed, and nothing will be lost.
This approach allows old versions of the Master Protocol to continue operating using the transactions they recognize without trying to parse messages of unknown meaning.
Generally, an out-dated parsing engine should either be upgraded to rejoin consensus, or retired by the owner. Implementations which are not in consensus can be used to attempt to defraud people
This section defines the fields that are used to construct transaction messages.
- Description: the currency used in the transaction
- Size: 32-bit unsigned integer, 4 bytes
- Inter-dependencies: Ecosystem
- Valid values:
- 1 and 3 to 2,147,483,647 in the real MSC ecosystem (2,147,483,646 unique values)
- 1 = Mastercoin
- 2 and 2,147,483,651 to 4,294,967,295 in the Test MSC ecosystem (Test MSC currencies and properties have the most significant bit set, values start with 0x80000003, yielding 2,147,483,646 unique values)
- 2 = Test Mastercoin
- 1 and 3 to 2,147,483,647 in the real MSC ecosystem (2,147,483,646 unique values)
- Description: Specifies whether a smart property is traded against test MSC or real MSC
- Size: 8-bit unsigned integer, 1 byte
- Inter-dependencies: Currency Identifier
- Valid values: 1 for MSC, 2 for Test MSC
- Description: used as a multiplier or in other calculations
- Size: 64-bit unsigned integer, 8 bytes
- Valid values: 0 to 9,223,372,036,854,775,807
- Description: used as a multiplier or in other calculations
- Size: 32-bit unsigned integer, 4 bytes
- Valid values: 0 to 4,294,967,295
- Description: used as a multiplier or in other calculations
- Size: 8-bit unsigned integer, 1 byte
- Valid values: 0 to 255
- Description: used as a multiplier or in other calculations
- Size: 16-bit unsigned integer, 2 bytes
- Valid values: 0 to 65535
- Description: the unique identifier assigned to each sale listing an a per address basis
- Size: 32-bit unsigned integer, 4 bytes
- Valid values: 0 to 4,294,967,295
- Description: Specifies the number of coins affected by the transaction this field appears in. Note: the number of coins is to be multiplied by 100,000,000 in this field (e.g. 100,000,000 represents 1.0 MSC), which allows for the number of Master Protocol coins to be specified with the same precision as bitcoins (eight decimal places).
- Size: 64-bit unsigned integer, 8 bytes
- Valid values: 1 to 9,223,372,036,854,775,807
- Description: indivisible or not
- Size: 16-bit unsigned integer, 2 bytes
- Valid values:
- 1: New Indivisible tokens
- 2: New Divisible currency
- 65: Indivisible tokens when replacing a previous property
- 66: Divisible currency when replacing a previous property
- 129: Indivisible tokens when appending a previous property
- 130: Divisible currency when appending a previous property
- Description: the seller's response to a buyer's offer to purchase
- Size: 8-bit unsigned integer, 1 byte
- Valid values:
- 1: Accept
- 2: Reject
- 3: Contact
- Description: a variable length string terminated with a \0 byte
- Size: variable, up to 255 bytes, plus the null terminator
- Valid values: UTF-8
- Description: number of blocks during which an action can be performed
- Size: 8-bit unsigned integer, 1 byte
- Valid values: 1 to 255
- Description: Datetime, assuming UTC timezone (the same timezone used by the bitcoin blockchain)
- Size: 64-bits standard unix timestamp, 8 bytes
- Valid values: http://en.wikipedia.org/wiki/Unix_time
- Description: number of seconds during which an action can be performed
- Size: 32-bit unsigned integer, 4 bytes
- Valid values: 1 to 31,536,000 (365.0 days)
- Description: the specific action to be applied to the sell offer by this transaction
- Size: 8-bit unsigned integer, 1 byte
- Valid values:
- 1: New
- 2: Update
- 3: Cancel
-
Description: the MSC Protocol function to be performed
-
Size: 16-bit unsigned integer, 2 bytes
-
Inter-dependencies: Transaction version
-
Current Valid values:
- 0: Simple Send
- 20: Sell Coins for Bitcoins (currency trade offer)
- 21: Offer/Accept Master Protocol Coins for Another Master Protocol Currency (currency trade offer)
- 22: Purchase Coins with Bitcoins (accept currency trade offer)
- 50: Create a Property with fixed number of tokens
- 51: Create a Property via Crowdsale with Variable number of Tokens
- 52: Promote a Property
- 53: Close a Crowdsale Manually
-
To be added in future releases:
- 2: Restricted Send
- 3: Pay Dividends (Send All)
- 10: Mark an Address as Savings
- 11: Mark a Savings Address as Compromised
- 12: Mark an Address as Rate-Limited
- 14: Remove a Rate Limitation
- 30: Register a Data Stream
- 31: Publish Data
- 40: Offer/Accept a Bet
- 60: List Something for Sale
- 61: Initiate a Purchase from a Listing
- 62: Respond to a Buyer Offer
- 63: Release Funds and Leave Feedback
- 100: Create a New Child Currency
- Description: the version of the transaction definition, monotonically increasing independently for each transaction type
- Size: 16-bit unsigned integer, 2 bytes
- Required/optional: Required
- Inter-dependencies: Transaction type
- Valid values: 0 to 65535
The Master Protocol Distributed Exchange transactions are listed below. Transactions 0, 20, 21, 22 and 50 are to be implemented in the first deployment, per this spec. They are listed first. The other transactions will be fully defined and implemented in future releases.
Each transaction definition has its own version number to enable support for changes to each transaction definition. Up thru version 0.3.5 of this spec, the transaction type field was a 4 byte integer. Since there were only 17 transactions identified, the upper 3 bytes of the field had a value of 0. For all spec versions starting with 0.4, the first field in each transaction message is the 2 byte version number, with an initial value of 0 and the transaction type field is a 2 byte integer. So, each client must examine the first two bytes of the transaction message to determine how to parse the remainder of the message. If the value is 0, then the message is in the format specified in version 0.3.5 of this spec. If the value is at least 1, then the message is in the format associated with that version number.
Master Protocol transactions are not reversible except as explicitly indicated by this spec.
Any Mastercoin transaction from any address that attempts to transfer, reserve, commit coins, or put coins in escrow while that address's available balance for that currency identifier is 0 will be invalidated.
##Transferring coins
Transfers are unconditional payments from one Mastercoin address to another address, set of addresses, or to the owners of a specific property (i.e. dividends)
###Transfer Coins (Simple Send)
Description: Transaction type 0 transfers coins in the specified currency from the sending address to the reference address, defined in Appendix A. This transaction can not be used to transfer bitcoins.
If the amount to transfer exceeds the number owned by the sending address, this indicates the user is transferring all of them.
[Future: Note that if the transfer comes from an address which has been marked as “Savings”, there is a time window in which the transfer can be undone.]
Say you want to transfer 1 Mastercoin to another address. Only 16 bytes are needed. The data stored is:
- Transaction version = 0
- Transaction type = 0
- Currency identifier = 1 for Mastercoin
- Amount to transfer = 100,000,000 (1.00000000 Mastercoins)
A simple send to a non-existent address will destroy the coins in question, just like it would with bitcoin. A simple send (or any other transaction) referencing a non-existent currency is invalid.
The Master Protocol allows users to trade coins without trusting a centralized website. When trading Mastercoins for bitcoins, this can be rather cumbersome, since it isn't possible to automatically match bids with asks, since we can't force the bidder to send bitcoins when a matching ask is found. When trading Mastercoins for other Master Protocol currencies, bids and asks are matched automatically.
Consequently, the messages below are different for mastercoin/bitcoin exchange than they are for exchange between mastercoin and other Master Protocol currencies, and the resulting UI must also be different, reflecting both the one-sided nature of bitcoin/mastercoin exchange as well as the additional anti-spam fees and race conditions inherent in the system.
Description: Transaction type 20 posts the terms of an offer to sell Mastercoins or Test Mastercoins for bitcoins. A new sell offer is created with Action = 1 (New). Valid currency identifier values for this transaction are 1 for MSC or 2 for Test MSC.
If the amount offered for sale exceeds the sending address's available balance (the amount not reserved, committed or in escrow), this indicates the user is offering to sell all coins that are available at the time this sell offer is published. The amount offered for sale, up to the amount available, will be reserved from the available balance for this address much like any other exchange platform. (For instance: If an address owns 100 MSC and it creates a "Sell Order" for at least 100 MSC, then the address's available balance is now 0 MSC, reserving 100 MSC.) After the sell offer is published, any coins received by the address are added to its then current available balance, and are not included in the amount for sale by this sell offer. The seller could update the sell offer to include these newly acquired coins, see Change a Coin Sell Offer below. Note that the amount reserved as a result of the update is based on the available balance at the time of the update plus the existing sell offer amount not yet accepted at the time of the update.
An address cannot create a new Sell Mastercoins for Bitcoins offer while that address has an active Sell Mastercoins for Bitcoins offer (one that has not been canceled or fully accepted and full payment received) for the same currency identifier.
Say you want to publish an offer to sell 1.5 Mastercoins for 1000 bitcoins. Doing this takes 34 bytes:
- Transaction version = 1
- Transaction type = 20 (currency trade offer for bitcoins)
- Currency identifier = 1 for Mastercoin
- Amount for sale = 150,000,000 (1.50000000 Mastercoins)
- Amount of bitcoins desired = 100,000,000,000 (1000.00000000 bitcoins)
- Time limit in blocks = 10 (10 blocks in which to send payment after counter-party accepts these terms)
- Minimum bitcoin transaction fee = 10,000,000 (require the buyer to pay a hefty 0.1 BTC transaction fee to the miner, discouraging fake offers)
- Action = 1 (New offer)
Note that some trading of Test MSC was done with version 0 of this message which did not have the Action field. Those transactions are treated as Action=3 (Cancel offer) when the Amount for sale is zero. For version 0 of this message and Amount for sale = 0 (Cancel offer), the values in the following fields are not tested for validity:
- Amount of bitcoins desired
- Time limit in blocks
- Minimum bitcoin transaction fee
For version 0 of this message and Amount for sale is non-zero, it is treated as Action=1 (New offer) unless there is already an offer outstanding from this address for the same Currency identifier, in which case it is treated as Action = 2 (Update offer).
An offer to sell coins can be changed by using Action = 2 (Update) until either: there are valid corresponding purchase offers (transaction type 22) for the whole amount offered, or the sell offer is canceled.
The change will apply to the balance that has not yet been accepted with a purchase offer. The UI must indicate if the update was successful and how many coins were purchased before the update took effect.
The amount reserved from the available balance for this address will be adjusted to reflect the new amount for sale.
Say you decide you want to change an offer, e.g. the number of coins you are offering for sale, or change the asking price. Send the transaction with the new values and the values that are not changing and Action = 2 (Update) before the whole amount offered has been accepted. Note that while the portion of an offer which has been accepted cannot be changed, sending an update message still has an effect, in that it affects any coins which have not been accepted, and it affects accepted coins if the buyer fails to send payment.
A currency sell offer can be canceled by using Action = 3 (Cancel) until the offer has been fully accepted by valid purchase offers (Purchase Mastercoins with Bitcoins). When a sell offer is canceled, the associated coins are no longer reserved.
When canceling a sell offer, the values in the following fields are not tested for validity:
- Amount for sale
- Amount of bitcoins desired
- Time limit in blocks
- Minimum bitcoin transaction fee
The cancel will apply to the amount that has not yet been accepted. The UI must indicate if the cancellation was successful and how many coins were not sold.
If you want to cancel an offer, use Action = 3 (Cancel) and send the transaction before the full amount for sale has been accepted. Note that while the portion of an offer which has been accepted cannot be canceled, sending the cancel message still has an effect, in that it cancels any portion of the offer which has not been accepted, and it prevents accepted coins from being relisted if the buyer fails to send payment.
Description: Transaction type 22 posts acceptance of an offer to sell Mastercoins for bitcoins. All or some of the coins offered can be purchased with this transaction.
The reference address must point to the seller's address, to identify whose offer you are accepting. The purchaser’s address must be different than the seller’s address.
If you send an offer for more coins than are available by the time your transaction gets added to a block, your amount bought will be automatically adjusted to the amount still available. When a Purchase Offer is sent to an address that does not have a matching active Sell Offer, e.g. the Sell offer has been canceled or is all sold out, the Purchase Offer must be invalidated.
Note: Your total expenditures on bitcoin transaction fees while accepting the purchase must meet the minimum fee specified in the Sell Offer in order for the transaction to be valid.
You must send the appropriate amount of bitcoins before the time limit expires to complete the purchase. Note that you must send the bitcoins from the same address which initiated the purchase. If you send less than the correct amount of bitcoins, your purchase will be adjusted downwards once the time limit expires. The remaining coins will be added back to those available in the Sell Offer if it’s still active. If you send more than the correct amount of bitcoins, your bitcoins will be lost (unless the seller chooses to return them to you). If you do not send complete payment before the time limit expires, the unpurchased coins will be added back to those available in the Sell Offer if it’s still active.
Please note that the buyer is allowed to send multiple bitcoin payments between the Purchase Offer and expiration block which are accumulated and used to adjust the Purchase Offer accordingly. The buyer's Mastercoin available balance is credited with the purchased coins when each bitcoin payment is processed.
In order to make parsing Master Protocol transactions easier, you must also include an output to the Exodus Address when sending the bitcoins to complete a purchase of Mastercoins. The output can be for any amount, but must be above the dust threshold.
Other Master Protocol messages (for instance if the buyer wants to change his offer) are not counted towards the actual purchase, even though bitcoins are sent to the selling address as part of encoding the messages.
Say you see an offer such as the one listed above, and wish to initiate a purchase of those coins. Doing so takes 16 bytes:
- Transaction version = 0
- Transaction type = 22 (accept currency trade offer)
- Currency identifier = 1 for Mastercoin
- Amount to be purchased = 130,000,000 (1.30000000 Mastercoins)
Description: Transaction type 21 is used to both publish and accept an offer to sell coins in a Master Protocol Currency for coins in another Master Protocol Currency.
If the amount offered exceeds the number available to be sold by the sending address, this indicates the user is offering to sell all of them. That amount will be reserved from the available balance for this address much like anfy other exchange platform.
An address cannot create a new offer while that address has an active sell offer with the same currencies in the same roles. An active sell offer is one that has not been canceled or fully accepted.
To accept a sell offer, simply publish the same message type with an inverse offer (e.g. selling Goldcoins for Mastercoins in the example below) at a price which matches or beats the seller's price. The protocol then finds orders that match and the coins from matching orders are considered transferred at the price specified by the earlier of the two offers. The purchaser’s address must be different than the seller’s address.
Note that when only some coins are purchased, the rest are still for sale with the same terms.
Say you want to publish an offer to sell 2.5 Mastercoins for 50 GoldCoins (coins which each represent one ounce of gold, derived from Mastercoins and described later in this document). For the sake of example, we'll assume that GoldCoins have currency identifier 3. Doing this takes 29 bytes:
- Transaction version = 1
- Transaction type = 21 (currency trade offer for another Master Protocol currency)
- Currency identifier = 1 for Mastercoin
- Amount for sale = 250,000,000 (2.50000000 Mastercoins)
- Currency identifier desired = 3 for GoldCoin
- Amount of GoldCoins desired = 5,000,000,000 (50.00000000 GoldCoins)
- Action = 1 (New offer)
Initially the UI should require that either the currency id for sale or the currency id desired be Mastercoins (or Test Mastercoins), since those currencies are the universal token of the protocol and the only ones which can be traded for bitcoins (and thus exit the Mastercoin ecosystem). This restriction is at the UI level and can be removed if someday more stable Master Protocol currencies become dominant and users no longer need to exit the Mastercoin ecosystem.
To change or cancel these order, use the action byte as described earlier for the message selling mastercoins for bitcoins. The only difference is that there are no coins "in limbo" (accepted but not purchased) complicating these messages.
The Master Protocol supports the creation of property tokens to be used for titles, deeds, user-backed currencies, and even investments in a company. Property tokens can be bought, sold, transferred, and used for betting, just as Master Protocol currencies are.
Properties are awarded currency identifiers in the order in which they are created. Mastercoin is currency identifier 1 (bitcoin is 0), and Test Mastercoins have currency identifier 2. Additional properties and currencies therefore start at ID #3. Properties issued and traded using real MSC are kept completely distinct from those issued and traded using Test MSC, so the ID numbering systems for the two ecosystems are independent. Test Mastercoin properties have the most significant bit set to distinguish them from real properties, and they cannot be traded against real Mastercoins nor otherwise interact with non-test properties. Test MSC property IDs also start numbering from 3, but with the most significant bit set. In sandbox environments using only Test MSC, these IDs can be displayed without the MSB set, for easier reading.
Every property has a property type, which defines whether it is divisible or not and whether the property replaces or appends a previous property. If creating 1,000,000 units of a divisible currency, choose property type 2 and specify 100,000,000,000,000 for the number of properties (1 million divisible to 8 decimal places). For 1,000,000 indivisible tokens for a company, choose property type 1 and specify 1,000,000 for the number of properties. The only difference between divisible and indivisible property types is how they are displayed (i.e. where the decimal point goes).
The attributes of an existing property cannot be changed. However, a new property can be created to replace or append an existing property. Only the address that issued a property can replace or append that property. Attempts by other addresses are invalid. A replaced property can still be used and traded as normal, but the UI should indicate to the user that a newer version of the property exists and link to it. To indicate that the issuer is abandoning a property entirely:
- set Previous Property ID to that property's id,
- set Number Properties to zero, and
- use one of the "replace" values for Property Type (see transaction types 50 and 51, below).
A property can be replaced and appended multiple times, even abandoning and un-abandoning it more than once. Appended properties must not be treated as the same asset in the UI or protocol parsers (the appended properties have independent values). When displaying a property, the UI should provide links to any related properties. Related properties are the property which was replaced or appended by this property (if there is one) as well as any properties from the same issuer which replace or append this property.
The Ecosystem for the property must be the same as the ecosystem for the "Currency identifier desired", i.e. both must be in the Mastercoin ecosystem or both must be in the Test Mastercoin ecosystem.
Any time the name of a property is displayed, the ID number of the property must also be displayed with it in the format "NAME (ID)", to avoid name collisions. For instance, "Quantum Miner (8)". This is very important to prevent a malicious user from creating a property to impersonate another property.
To help distinguish legitimate companies and ventures from scams, spam, and experiments, the Master Protocol allows users to spend Mastercoins for the purpose of promoting a smart property. When UI clients display smart properties, the default ordering should be based on how many Mastercoins have been spent for promoting the property, adjusted for how long ago the Mastercoins were spent. Details on promoting a smart property by spending Mastercoins and how that affects sort ordering can be found below.
The "Property Data" field is general-purpose text, but can be used for things like storing the hash of a contract to ensure it is in the block-chain at property creation (i.e. "Proof of Existence").
Description: Transaction type 50 is used to create a new Smart Property with a fixed number of tokens.
If creating a title to a house or deed to land, the number of properties should be 1. Don’t set number of properties to 10 for 10 pieces of land – create a new property for each piece of land, since each piece of land inherently has a different value, and they are not interchangeable.
Once this property has been created, the tokens are owned by the address which broadcast the message creating the property.
Say you want to do an initial distribution of 1,000,000 digital tokens for your company “Quantum Miner”. Doing so will use a varying number of bytes, due to the use of null-terminated strings. This example uses 80 bytes:
- Transaction version = 0
- Transaction type = 50
- Ecosystem = 1 for tradable within Mastercoin ecosystem (as opposed to Test Mastercoin)
- Property Type = 1 for new indivisible tokens
- Previous Property ID = 0 for a new smart property (or the existing property ID if replacing or appending)
- Property Category = “Companies\0” (10 bytes)
- Property Subcategory = “Bitcoin Mining\0” (15 bytes)
- Property Name = “Quantum Miner\0” (14 bytes)
- Property URL = “tinyurl.com/kwejgoig\0” (21 bytes)
- Property Data = “\0” (1 byte)
- Number Properties = 1,000,000 indivisible tokens
Description: Transaction type 51 is used to initiate a crowdsale which creates a new Smart Property with a variable number of tokens.
Say that instead of creating tokens and selling them, you'd rather do a kickstarter-style crowdsale to raise money for your "Quantum Miner" venture, with investors getting tokens for Quantum Miner in proportion to their investment, and the total number of tokens distributed being dependent on the amount of investment received. You want each Mastercoin invested over the next four weeks (ending January 1st, 2215) to be worth 100 tokens of Quantum Miner, plus an early-bird bonus of 10%/week for people who invest before the deadline, including partial weeks. You also wish to grant yourself a number of tokens equal to 12% of the tokens distributed to investors as compensation for all your R&D work so far. This grant to yourself is in addition to the tokens distributed to investors. This transaction message will use a varying number of bytes, due to the use of null-terminated strings. This example uses 101 bytes:
- Transaction version = 0
- Transaction type = 51
- Ecosystem = 1 for tradable within Mastercoin ecosystem (as opposed to Test Mastercoin)
- Property Type = 1 for new indivisible tokens
- Previous Property ID = 0 for a new smart property (or the existing property ID if replacing or appending)
- Property Category = “Companies\0” (10 bytes)
- Property Subcategory = “Bitcoin Mining\0” (15 bytes)
- Property Name = “Quantum Miner\0” (14 bytes)
- Property URL = “tinyurl.com/kwejgoig\0” (21 bytes)
- Property Data = “\0” (1 byte)
- Currency identifier desired = 1 for Mastercoin (cannot be bitcoin)
- Number Properties per unit invested = 100 indivisible tokens
- Deadline = January 1st, 2215 00:00:00 UTC (must be in the future)
- Early bird bonus %/week = 10
- Percentage for issuer = 12
Funds raised are locked and cannot be spent or otherwise used until after the crowdsale deadline or the crowdsale is manually closed (to prevent using the same funds to purchase tokens multiple times).
A MSC address may have only one crowdsale active per ecosystem at any given time, eliminating the need for participants to specify which crowdsale from that address they are participating in when they purchase.
Participating in a crowdsale is accomplished by sending coins to the crowdsale owner's address with the Simple Send transaction. Use multiple Simple Send messages to make multiple purchases in the crowdsale. In order to participate in the crowdsale, the currency id must match the "Currency identifier desired" value in the crowdsale and each Simple Send message must be confirmed by the "Deadline" value in the crowdsale.
For divisible properties, the sending address will receive the number of tokens calculated as the "Number Properties per unit invested" value multiplied by the number of coins (units) specified in the Simple Send message, to eight decimal places. For indivisible properties, the sending address will receive the number of tokens calculated as the "Number Properties per unit invested" value multiplied by the number of coins (units) specified in the Simple Send message, rounded down to an integer number of tokens (with no fractional portion). The UI should accurately display the number of tokens that will be received.
A few details are important to have here:
- If the transaction is not in the correct currency, no purchase will be made and no tokens will be received, but the Simple Send itself will complete if it is valid.
- Payments will be applied to whatever crowdsale is active at the time of confirmation if the currency specified matches the crowdsale's "Currency identifier desired".
- If the transaction is confirmed after the crowdsale deadline or if for any other reason no crowdsale is active, no purchase will be made and no tokens will be received, but the Simple Send itself will complete.
- Tokens received are immediately added to the available balance belonging to the sending address and can be spent or otherwise used by that address.
Say that having created your "Quantum Miner" smart property (which was assigned property ID #8) you now want it to show up higher in the list of properties. You decide to spend 3 Mastercoins to promote your smart property so that it is displayed higher in the list than all the spam/scam/experimental properties. Doing so takes 13 bytes:
- Transaction version = 0
- Transaction type = 52
- Ecosystem = 1 for a property within the Mastercoin ecosystem (as opposed to Test Mastercoin)
- Property ID = 8
- Number of Mastercoins = 300,000,000 (3.00000000 Mastercoins)
This transaction permanently destroys Mastercoins in exchange for favorable placement of this property in the default sort-ordering of properties on every UI. Protocol parsers accumulate all promotions of a property (which can be done by any address which has Mastercoins), with newer promotions being worth more than older promotions.
To accomplish this time-weighting, a promotion is worth (# Mastercoins spent) * 3^(years since exodus), where "years since exodus" is the number of years (including partial years) since the Mastercoin fund-raiser ended on September 1st 2013, and thus new promotions are always worth 3x as much as year-old promotions and 9x as much as two-year-old promotions if the same number of Mastercoins were spent on each.
UIs will probably also choose to offer other sort orderings, such as by transaction volume, removing the need to continually promote a property once it is well-established. Categories and subcategories should be similarly sorted, using the sum of the promotions they contain by default with other sorting available such as the sum of the transaction volumes. UI designers should expect the number of spammy properties, categories, and sub-categories to be quite large, so intelligent sorting will be important.
In the Test Mastercoin ecosystem, test MSC are destroyed instead of real MSC.
Since crowdsales are generally open-ended, it leaves the potential that raising far more funds than intended could dilute the value of tokens sold early in the crowdsale to an unacceptable level. To prevent this, the address that created the crowdsale can issue a command to close the crowdsale manually. It is invalid to attempt to close a crowdsale that is not active. Closing an active crowdsale requires 8 bytes. For example, to close the crowdsale that was assigned Property ID 9, the transaction message is:
- Transaction version = 0
- Transaction type = 53
- Property ID = 9
Note that attempts to participate in a closed crowsale will result in no investment in that crowdsale and no tokens from that crowdsale will be received. See Participating in a Crowdsale for details.
The transactions below are still subject to revision and therefore are not included in deployments based on this version of the spec.
The Master Protocol defines some transactions which effectively lock funds from being spent quickly, making theft of a "savings" wallet much more difficult, even if that wallet is online.
- Transaction version = 0
- Transaction type = 10
- Reversibility period = 2,592,000 (30 days)
Marking an address as savings is PERMANENT and cannot be undone. If an address is marked as savings, the reversibility rules affect not only Mastercoins, but any Master Protocol child currency stored at that address.
When marking an address as savings, the reference payment points to a “guardian” address authorized to reverse fraudulent transactions. The guardian address should preferably be from an unused offline or paper wallet. The sending address is the address to be marked as savings.
When a fraudulent transaction is reversed, any pending funds go to the guardian address, rather than going back to the compromised savings address. Also, any funds which remain in the compromised address also go to the guardian wallet.
Say you send funds out of a savings wallet. Doing so requires using a transaction identical to version 0 of "simple-send", but with the transaction type of 2:
- Transaction version = 0
- Transaction type = 2
- Currency identifier = 1 for Mastercoin
- Amount to transfer = 100,000,000 (1.00000000 Mastercoins)
An address marked as savings can only do this "restricted send" transaction type. All other transaction types must be ignored, as they are invalid from a savings address. This transaction type is also used for sending from rate-limited wallets.
Say you notice that the address you marked as savings has been compromised, and you want to reverse transactions and transfer everything to the guardian address. Doing this takes 4 bytes:
- Transaction version = 0
- Transaction type = 11 for marking a compromised savings address
This transaction must be sent from the guardian address. The reference payment must be to the compromised savings address. Funds from any pending transactions and any remaining funds will then be transferred to the guardian address, both Mastercoins and any other Master Protocol currencies.
The savings/guardian model is intended to allow the user to take extreme precautions against accidental loss of the savings address (for instance, by storing lots of backups, including in the cloud), and extreme precautions against theft of the guardian address. Although reasonable precautions should be taken, if your savings address gets hacked, or the key to your guardian address gets lost or destroyed, the coins can still be recovered.
This model also facilitates estate planning. You simply give your heir(s) a paper copy to the private key of your savings address, but you keep the guardian address key to yourself. If you die, your heirs can simply transfer the funds out of your savings (they will have to wait for the reversibility period to pass), but they can't steal from you while you are alive since you are the only one with the key to the guardian address and can reverse their transaction if they try.
It should be obvious that anyone parsing Mastercoin transactions for payment must check that the payment is not reversible before completing the transaction!
Say you want to enforce a spending limit of 1 Mastercoin per Month on one of your addresses. Doing this takes 20 bytes:
- Transaction version = 0
- Transaction type = 12
- Currency identifier = 1 for Mastercoin
- Spending Limit = 100,000,000 (1.00000000 Mastercoins)
- Limitation Reset period = 2,592,000 (30 days)
Marking an address as rate-limited only affects the specified currency. Other currencies stored in the address are not rate-limited. The limitation reset period begins once the protected address makes a send. Attempting to send beyond the rate limit results in the maximum send possible under the limit.
When marking an address as rate-limited, the reference payment must point to a “guardian” address authorized to remove the limitation. The guardian address should preferably be from an unused offline or paper wallet. The sending address must be the address to be marked as rate-limited. Note that an address could be marked as savings AND rate limited, with the same or different guardian addresses.
An address marked as savings can only do Restricted Send transactions as described above. All other transaction types must be ignored, as they are invalid from a rate-limited address.
Removing the rate limitation above takes 8 bytes:
- Transaction version = 0
- Transaction type = 14
- Currency identifier = 1 for Mastercoin
This transaction must be sent from the guardian address in charge of the rate limitation. The reference payment must be to the rate-limited address. Removing the limit affects only the specified currency, and not any other rate-limited currencies stored at that address.
The Master Protocol allows users to publish data onto the bitcoin block-chain, which other users can then bet on.
(AKA Data Feed)
Say you decide you would like to start publishing the price of Gold in the block chain. Registering your data stream takes a varying number of bytes due to the use of null-terminated strings. This example uses 57 bytes:
- Transaction version = 0
- Transaction type = 30
- Ecosystem = 1 for useable within Mastercoin ecosystem (as opposed to Test Mastercoin)
- Parent currency identifier = 1 for Mastercoin (the price of Gold will be published in units of Mastercoin)
- Category = “Commodities\0” (12 bytes)
- Sub-Category = “Metals\0” (7 bytes)
- Label = “Gold\0” (5 bytes) (if a second “Gold” is registered in this sub-category, it will be shown as “Gold-2”)
- Description/Notes = “tinyurl.com/kwejgoig\0” (21 bytes) (Please save space in the block chain by linking to your description!)
The reference payment must be to the bitcoin address which will be publishing the data.
Each data stream gets a 4-byte unique identifier, determined by the order in which they were registered. For instance, if your data stream was the third data stream ever registered, your data stream identifier would be 3. Note that data streams in the Test MSC ecosystem are completely independent, and have the most significant bit set to distinguish them from normal data streams. However, in sandbox environments using only Test MSC, these IDs can be displayed without the MSB set, for easier reading.
Since anyone can cheaply register a data stream, and thereby create categories and subcategories, we can assume that there will be a lot of noise. Anyone writing code to display data stream categories should note which data streams are the most actively used, and order categories and subcategories by descending activity, thereby pushing unused categories to the bottom of the list.
If you ever need to change the description/notes for your data stream (for instance, if some poor sport takes down your website), simply re-register it from the same address with the same category, subcategory, and label. When re-registering, you can also change the ticker address by choosing a different address for the reference payment (for instance, if your ticker address gets compromised), or change the display multiplier.
If you wish to cancel your data stream (and all unsettled bets on it), update the datastream to have an empty category, subcategory, and label (null character only for each).
Say you decide you would like publish that today's gold price is 15 Mastercoins per ounce, using the datastream described above. Doing so takes 13 bytes:
- Transaction version = 0
- Transaction type = 31
- Ecosystem = 1 for useable within Mastercoin ecosystem (as opposed to Test Mastercoin)
- Data = 1,500,000,000 (15.00000000 Mastercoins per ounce of gold)
Say you want to use USDCoins (another hypothetical currency derived from Mastercoin, each USDCoin being worth one U.S. Dollar) to bet $200 that the gold ticker will not rise above 20 Mastercoins/Ounce in the next 30 days at 2:1 odds. For the sake of example, we will assume that USDCoins have currency identifier 5. Creating this bet takes 36 bytes:
- Transaction version = 0
- Transaction type = 40 for creating a bet offer (32-bit unsigned integer, 4 bytes)
- Bet Currency identifier = 5 for USDCoin (32-bit unsigned integer, 4 bytes)
- Data Stream identifier = 3 for the Gold ticker, per our data stream example (32-bit unsigned integer, 4 bytes)
- Bet Type = 35 for “Will not exceed on or before” (See table below) (16-bit unsigned integer, 2 bytes)
- Bet threshold (Non-CFDs only) = 200,000 (0.00200000 BTC, which equates to a ticker value of 20 per our data stream example) OR Leverage (CFDs only) = 65536 (1x leverage) (32-bit unsigned integer, 4 bytes)
- Settlement Date = January 1st, 2215 00:00:00 UTC (8 bytes)
- Amount of wager = 20,000,000,000 (200.00000000 USDCoins) (64-bit unsigned integer, 8 bytes)
- Amount of counter-wager = 10,000,000,000 (100.00000000 USDCoins) (64-bit unsigned integer, 8 bytes)
Since this bet is not a CFD (described later) "bet threshold" is used rather than "leverage".
By offering $200 against $100, the desired 2:1 odds are implied. Since one address might want to have multiple similar wagers, it is not possible to change a bet (you must cancel and then broadcast a new bet). To cancel your bet, rebroadcast it with all the same data except set the amount of wager to zero.
Table of Bet Types
| 0 | Will equal on | 32 | Will equal on or before |
| 1 | Will not equal on | 33 | Will not equal on or before |
| 2 | Will exceed on | 34 | Will exceed on or before |
| 3 | Will not exceed on | 35 | Will not exceed on or before |
| 4 | Will be below on | 36 | Will be below on or before |
| 5 | Will not be below on | 37 | Will not be below on or before |
| 6 | Bullish Contract for Difference | ||
| 7 | Bearish Contract for Difference |
A "Contract for Difference" (CFD) allows a bettor to temporarily gain bullish or bearish exposure to a price movement, in direct proportion to that movement. A bettor who creates a bullish CFD on Gold with 1x leverage (65536) will receive 10% of the counter-wager funds if Gold rises 10% during the period of the bet. If instead Gold falls 10%, the bettor loses 10% of his own money at stake. As with normal bets, 0.5% of the total pot goes to the creator of the data stream before winnings are determined.
CFD bets store "leverage" in place of the data used by "bet threshold" in other bet types. If a bettor prefers that a 10% price movement means a 20% gain or loss, they may select 2x leverage (65536*2=131072). Similarly, a 10% price movement could mean a 5% gain or loss using 0.5x leverage (65536*0.5 = 32768). Just as with normal bets, a CFD bettor can "sweeten the deal" by offering better odds (a lower counter-wager amount). High-leverage bets or big price movements could result in a winnings calculation higher than the amount at stake, in which case the winner simply gets the entire pot.
Say you see a bet which you would like to accept. Simply publish the inverse bet with matching odds and the same end date, and the Master Protocol will match them automatically (that is, everyone parsing Mastercoin data will mark both bets as accepted). Here is what a bet matching our last example would look like:
- Transaction version = 0
- Transaction type = 40 for creating a bet offer (32-bit unsigned integer, 4 bytes)
- Bet Currency identifier = 5 for USDCoin (32-bit unsigned integer, 4 bytes)
- Data Stream identifier = 3 for the Gold ticker, per our data stream example (32-bit unsigned integer, 4 bytes)
- Bet Type = 34 for “Will exceed on or before” (See table above) (16-bit unsigned integer, 2 bytes)
- Bet threshold (Non-CFDs only) = 200,000 (0.00200000 BTC, which equates to a ticker value of 20 per our data stream example) OR Leverage (CFDs only) = 65536 (1x leverage) (32-bit unsigned integer, 4 bytes)
- Settlement Date = January 1st, 2215 00:00:00 UTC (8 bytes)
- Amount of wager = 5,000,000,000 (50.00000000 USDCoins) (64-bit unsigned integer, 8 bytes)
- Amount of counter-wager = 10,000,000,000 (100.00000000 USDCoins) (64-bit unsigned integer, 8 bytes)
Note that this bet will be matched against only half of the previous example, because while the odds match (2:1 vs. 1:2), the amount of this bet is for less. This bet is only for $50, so would only win $100 if they win, as opposed to the full $200. Once the bets are matched, the first bet still has $100 available for someone else to bet $50 against.
Once GoldCoins reach a value of 20 or the bet deadline passes, the bet winner gets 99.5% of the money at stake. The other 0.5% goes to the creator of the data stream.
##Transferring coins (Future)
We are not sure the "pay dividends" message will be feasible, given that it potentially affects a huge number of balances. Consequently, it is currently in the "future transactions" bucket. It might become feasible if some kind of anti-spam fee is added to make sure this message is used sparingly.
Say your company has made a huge profit and wishes to pay 1000 MSC evenly distributed among the holders of Quantum Miner digital tokens. Doing so will use 20 bytes:
- Transaction version = 0
- Transaction type = 3 for "send all" (32-bit unsigned integer, 4 bytes)
- Currency identifier = 1 for Mastercoin (32-bit unsigned integer, 4 bytes)
- Amount to transfer = 100,000,000,000 (1000.00000000 Mastercoins) (64-bit unsigned integer, 8 bytes, should not exceed number owned, but if it does, assume user is transferring all of them)
- Currency ID of Payees = 6 for Quantum Miner Tokens (32-bit unsigned integer, 4 bytes)
Note that this transaction is very similar to "simple send", with just one extra field. The protocol will split up the 1000 MSC among the investors, according to how many tokens they have.
Another use-case for this transaction type would be a giveaway, where someone wants to raise interest in their new coin or property by giving some away to everyone who owns (for instance) Mastercoins.
The Master Protocol allows for the buying and selling of physical goods in a sort of distributed classified ads system, with purchase money held in escrow by the protocol. Some might call this a "distributed e-bay", while the cynical might call it a "distributed silk road". Due to the potential for black-market uses of this feature, we encourage our users to know and follow the laws of their respective jurisdictions.
Say you want to sell a Bible for 0.001 Mastercoins. Creating a sell offer will use a variable number of bytes due to the use of null-terminated strings:
- Transaction version = 0
- Transaction type = 60 for sale listing (32-bit unsigned integer, 4 bytes)
- Currency identifier of price = 1 for Mastercoin (32-bit unsigned integer, 4 bytes)
- Desired price = 100,000 (0.00100000 Mastercoins) (64-bit unsigned integer, 8 bytes)
- Item category = "Contraband\0" (11 bytes)
- Item subcategory = "Forbidden Books\0" (16 bytes)
- Item title = "Bible, NASB\0" (12 bytes)
- Description/Notes = “tinyurl.com/kwejgoig\0” (21 bytes) (Please save space in the block chain by linking to your description!)
Every sale offer published by a given address gets a 32-bit "Listing ID" number assigned, which increments for each item offered for sale from that address. We'll assume this is the first item offered for sale from this address (Listing ID=0).
To delist an unsold item, publish the exact same message, but with a price of zero. Sellers should make sure they provide some method of contacting them (for instance, on the listing webpage), so they have a communication channel to help resolve disputes with buyers.
Say you see the Bible listed above and wish to purchase it. However, you have no reputation as a buyer, so you want to offer a 10% higher purchase price than what the seller is asking. You want your purchase offer to expire in 3 days, which is 1/1/2225. Starting the purchase process takes 24 bytes:
- Transaction version = 0 (2 bytes)
- Transaction type = 61 for Initiate purchase from listing (2 bytes)
- Listing ID = 0 (the ID for the listing above) (32-bit unsigned integer, 4 bytes)
- Expiration Date = January 1st, 2215 00:00:00 UTC (8 bytes)
- Offered price = 110,000 (0.00110000 Mastercoins) (64-bit unsigned integer, 8 bytes)
The reference address points to the address which listed the Bible for sale. The seller now has 3 days to accept this buyer before the offer expires. The buyer's money is now locked in escrow until their offer expires or the purchase is complete.
The purchaser may also offer less than the suggested price. This may be viable for an established buyer and/or a stale listing.
If the buyer offers a bad price, has a bad reputation, or has no reputation, then you may not wish to do business with them. If you see an offer that you like, the message to accept the offer takes X bytes:
- Transaction version = 0
- Transaction type = 62 for Accept buyer offer (32-bit unsigned integer, 4 bytes)
- Which buyer = 2 (3rd offer received) (16-bit unsigned integer, 2 bytes)
Once a buyer has been accepted, the seller may ship the Bible.
Once a buyer has been accepted, they may release funds held in escrow (or destroy those funds) and leave feedback. To do so takes a variable number of bytes due to the use of a null-terminated string:
- Transaction version = 0
- Transaction type = 63 for Release Funds and Leave Feedback (32-bit unsigned integer, 4 bytes)
- Listind ID = 0 (the ID for the listing above) (32-bit unsigned integer, 4 bytes)
- Percentage of funds to release = 105% (65536*1.05 68813) (32-bit unsigned integer, 4 bytes)
- Text feedback = “tinyurl.com/kwejgoig\0” (21 bytes) (Please save space in the block chain by linking to your feedback!)
The reference address points to the address which listed the Bible for sale. Funds which are not released are permanently destroyed. Specifying more than 100% signifies an additional tip beyond the funds held in escrow. Funds are released automatically after 60 days if the buyer never leaves feedback. In addition to the text feedback, each transaction gets "1 star" to "5 stars" based on the following criteria:
- 1 Star: All funds destroyed (very unhappy customer)
- 2 Stars: Some funds destroyed
- 3 Stars: No funds destroyed, no tip
- 4 Stars: Tip < 10%
- 5 Stars: Tip >= 10%
In order to avoid people gaming the reputation system, some coins must be destroyed with every purchase. The percentage of coins destroyed goes down with each new purchase. The percentage is calculated as 2*(value of this purchase) / (value of all purchases, including this one). Note that this formula causes 50% of the coins from the first purchase to be destroyed.
The most important and also the most controversial feature (at least the escrow backed part) of the Master Protocol is the built-in support for users to create their own currencies out of existing Mastercoins. For the purposes of demonstrating how user currencies will work, we will use an example currency called “GoldCoins”, which are intended to track the value of one ounce of gold, and which may be stored, transferred, bought, and sold similarly to Mastercoins.
So how do we drive the value of these GoldCoins to their target value, when demand for them may surge and decline? The price of GoldCoins is decided by the balance of supply and demand. Since we can’t control the demand for GoldCoins, we must control the supply. The key to accomplishing this is to use an escrow fund which holds Mastercoins, as shown below:
The escrow fund operates like a battery on the power grid, charging when there is excess energy then discharging where there isn't enough. When there are too few GoldCoins (GoldCoin price is too high), the escrow fund releases new GoldCoins, and the escrow-battery “charges” by holding Mastercoins in escrow. When there are too many GoldCoins (GoldCoin price is too low), the escrow fund purchases some of the excess GoldCoins, thereby “discharging” the escrow-battery as it releases the stored Mastercoins.
Say you want to create the GoldCoin currency described above, using the Gold data stream we defined. Doing so will use a varying number of bytes, due to the use of a null-terminated string. This example uses 38 bytes:
- Transaction version = 0
- Transaction type = 100 for creating a new child currency (32-bit unsigned integer, 4 bytes)
- Data Stream identifier = 3 for the Gold ticker, per our data stream example (32-bit unsigned integer, 4 bytes)
- Escrow fund delay = 4 for 4 days (see below) (8-bit unsigned integer, 1 byte)
- Escrow fund aggression factor = 1,000,000 for 1% (See below) (32-bit unsigned integer, 4 bytes)
- Currency Name = “GoldCoin\0” (9 bytes)
- Escrow Fund Initial Size = 100,000,000,000 for 1,000 Mastercoins (64-bit unsigned integer, 8 bytes, causes 1,000 Mastercoins to be debited from the currency creator and credited to the escrow fund. This number should not exceed the amount owned by the creator, but if it does, assume they are crediting all their Mastercoins to the escrow fund)
- Escrow Fund Minimum Size = 99,000,000 for 99% (32-bit unsigned integer, 4 bytes, if the escrow fund value is ever less than 99% of all GoldCoins, the currency is dissolved and the escrow fund is distributed to GoldCoin holders who would take a 1% loss)
- Sale/Transfer Penalty = 100,000 for 0.1% (32-bit unsigned integer, 4 bytes, any time GoldCoins are sold or transferred, 0.1% are destroyed, which improves the health of the escrow fund)
As with properties, currencies are awarded currency identifiers in the order in which they are created. Mastercoin is currency identifier 1 (bitcoin is 0), and Test Mastercoins have currency identifier 2, so if GoldCoin is the first Master Protocol currency, it will get a currency identifier of 3.
The currency held in escrow is the parent currency of the data stream. In this example it is Mastercoins, but it could also be any currency derived from Mastercoins. For instance, GoldCoins could later be held in escrow to support a currency whose data stream uses GoldCoins as a parent currency.
The escrow fund delay of 4 days means that the price of GoldCoins must be too high (or too low) for 4 days in a row before the escrow fund will take any action.
The escrow fund aggression factor determines how aggressively the escrow fund corrects the price of GoldCoins when their price diverges from their target. An escrow fund with aggression factor of 0 will never take any action. If the aggression factor is 100%, the escrow fund will take the maximum possible action (buying every GoldCoin for sale above the target price, or selling new GoldCoins to every buyer below the target price).
In the case of a 1% aggression factor, the escrow fund's first action will be to fix 1% of the error. If the error the next day is still in the same direction, the escrow fund will fix 2% of the error, then 3% the next day, and so on until it reaches 100% or the error changes direction. Once the error changes its direction, the escrow fund has done its job and it starts counting again from zero.
The fields Escrow Fund Initial Size, Escrow Fund Minimum Size, and Sale/Transfer Penalty were added in response to the “bytemaster/d’aniel attack”, which becomes possible once malicious actors are able to short these currencies. The attack only works on currencies with underfunded escrows, and consists of a malicious actor creating a competing GoldCoin with a healthy escrow fund, which the market would presumably prefer over the GoldCoin with the unhealthy escrow fund. The malicious actor could then profit by shorting the unhealthy GoldCoin until people panicked and fled for the healthy version. More information about unhealthy escrow funds can be found in the next section.
What if the price of Mastercoins falls 95%, and the value of the escrow fund is now only 5% of the target value of all GoldCoins? Using the battery analogy, this escrow fund now has less “charge” and is therefore less capable of intervening to correct prices.
If the currency creator had set the minimum escrow size to 100% the escrow fund would never get into this situation because it would simply dissolve and pay out to currency stakeholders as soon as the escrow fund value dropped to parity, with zero or minimal losses. For currencies which are set up to allow continued operation once unhealthy, the protocol responds by adjusting the aggression factor accordingly. In the example of GoldCoins backed by only 5% given above, the 1% aggression factor would be multiplied by 5% to get 0.05%, meaning that the adjustments will be of much smaller magnitude, and it will take a lot longer to get to 100% aggression.
Note that escrow funds holding funds worth more than their currency do not get more aggressive. That is, if the GoldCoins escrow fund is worth twice the value of all GoldCoins in existence, the aggression factor is still 1%.
Given a reasonably stable Mastercoin, escrow funds should generally grow healthier over time. Our GoldCoin escrow fund, when it does act, is buying GoldCoins when they are cheap, and selling them when they are expensive. Thus it will generally tend to make a profit, and the Mastercoins held by the escrow fund will grow. The larger the escrow fund, the lower the chance of the currency failing to maintain its value. Additionally, the currency creator can optionally supply initial escrow funds if desired, and the currency can be tuned to destroy some GoldCoins with every sale or transfer, further increasing escrow fund health.
When an escrow fund is unhealthy, lowering the aggression factor makes the escrow fund take more profitable trades, which increases the likelihood of recovery. For instance, if it is buying excess GoldCoins, the cheapest 0.05% can be purchased at a better average price than the cheapest 1% on the market.
Escrow funds should generally be tuned to act slowly. This will allow arbitrage traders to do the heavy lifting, as the knowledge that the escrow fund will eventually get the price back to the target makes for a self-fulfilling prophecy when traders act on that knowledge. If the escrow fund acts too quickly, it loses money when the bitcoin version of a security leads the real-world version, as would happen if someone was engaging in insider trading anonymously using the bitcoin version.
By Zathras, Copyright © 2013 The Mastercoin Foundation
The following appendix serves to detail the different approaches to storing Mastercoin transaction data in the Bitcoin blockchain along with their validity requirements and use cases.
This appendix will not discuss the varying types of Mastercoin transaction or what the transaction data contains (these are defined in the main body of the Mastercoin specification) and will focus solely on transaction data storage.
For the purposes of a simplified overview, parties wishing to develop Mastercoin software should support the decoding of both Class A and Class B transactions, but only need support encoding of Class B transactions.
Note that for all transaction classes, we have some unused "padding" bytes at the end of most messages. Those bytes are undefined (they are ignored, so they can have any value).
Class A transactions were the first class of Mastercoin transaction and store data in the blockchain by utilizing fake Bitcoin addresses to encode transaction data.
The transaction data is encoded into said fake Bitcoin address which is then used as an output in a single Bitcoin transaction satisfying the following requirements:
- Has a single or the largest input signed by the sending address
- Has an output for the recipient address (the 'reference' address)
- Has an output for the exodus address
- Has an output for the encoded fake address (the 'data' address)
- Has all output values above the 'dust' threshold (currently 0.00005460 BTC) and preferable be equal.
- Has exactly two non-Exodus outputs (one of which must be the data address) with a value equal to the Exodus output and/or has exactly one output with a sequence number +1 of the data address for reference output identification
- Additional outputs are permitted for the remainder of the input (the 'change' address)
NOTE: The sequence number for a given address is defined as a 1 -byte integer stored as the first byte of each 'packet'. Sequence numbers are continuous with 0 following 255 (256=0, 255+1=0).
NOTE: Should a transaction result in an edge case that provides conflicting reference address values for sequence numbers and equal outputs, the reference address identified via equal outputs will take precedence.
As there is no private key associated with these fake addresses they are inherently unspendable. This creates concerns around blockchain bloat, especially within the UTXO (Unspent Transaction Output) set as each use of a fake address adds an unspent output to the UTXO dataset that will never be redeemed, thus growing (or ‘bloating’) it.
As the UTXO set is designed to be memory resident it is thus in the interests of Bitcoin to avoid UTXO bloat to minimize the memory requirement for client implementations.
Class B transactions were developed to address this issue by using provably redeemable outputs. Class A transactions are thus considered deprecated and are supported for backwards compatibility only.
NOTE: Class A transactions are restricted to the ‘simple send’ transaction type only. All other Mastercoin transaction types are supported by Class B transactions only. Client implementations should utilize Class B for all transaction types, including ‘simple send’.
Class B transactions attempt to address the UTXO ‘bloat’ issue by storing data in the blockchain by utilizing ‘1-of-n’ multisignature outputs where one of the signatories should be the sender.
By adopting a ‘1-of-n’ approach (credit Tachikoma @ bitcointalk) we can increase n to the number of packets (public keys) needed to store the transaction data while maintaining the ability of the sender to redeem the output.
NOTE: The reference client currently supports a maximum value of 3 for n. As one signatory should be the sender for redemption purposes, there is a current limit of 2 data packets per output. A number of multisig outputs can be combined to increase the space available for transaction data as required. On decoding all Mastercoin packets from all multisig outputs are ordered via their sequence number and evaluated as a continuous data stream.
Transaction data is encoded into one or a number of compressed public keys which are obfuscated and then should have their last byte manipulated to form a valid ECDSA point. These compressed public keys then can be included as signatories in a multisig output ordered by their sequence number.
The size of a Mastercoin packet in a compressed public key is thus 31 bytes (33 bytes minus the first and last bytes for the key identifier (02) and ECDSA manipulation byte). The Mastercoin packet reserves the first byte for the sequence number, providing a total of 30 bytes per packet for Mastercoin transaction data. The range of sequence numbers in a Class B transaction is 1 to 255, providing for a total 7,650 bytes maximum actual transaction data storage per Mastercoin Class B transaction.
Sequence numbers are again used to order the packets (again first byte of the packet), however as we no longer need to use sequence numbers to identify the recipient (reference) address we are able to start the sequence at one (we do not start the sequence at zero due to our need for a positive sequence number in obfuscation).
Obfuscation is performed by SHA256 hashing the sender's address S times (where S is the sequence number) and taking the first 31 bytes of the resulting hash and XORing with the 31 byte Mastercoin packet. Multiple SHA256 passes are performed against an uppercase hex representation of the previous hash.
EXAMPLE: The following provides example output for an obfuscated Mastercoin packet (where and XX is the last byte reserved for ECDSA point validity manipulation):
| REFERENCE ADDRESS | {1CdighsfdfRcj4ytQSskZgQXbUEamuMUNF } |
| SHA256 HASH (S TIMES) OF ADDRESS | {1D9A3DE5C2E22BF89A1E41E6FEDAB54582F8A0C3AE14394A59366293DD130C }59 |
| CLEARTEXT MASTERCOIN PACKET | 02{ 0100000000000000010000000002faf0800000000000000000000000000000 }XX |
| OBFUSCATED MASTERCOIN PACKET | 02{ 1C9A3DE5C2E22BF89B1E41E6FED84FB502F8A0C3AE14394A59366293DD130C }XX |
Once the obfuscated Mastercoin packet is prepared, the key identifier (02) is prefixed and a random byte compressed public key is then run across a check to ensure the key is a valid ECDSA point. If the key fails this check, the last byte is simply rotated with a different random byte and tested again until the key forms a valid ECDSA point.
These compressed public key 'packets' can then be included in one or multiple OP_CHECKMULTISIG output along with the senders public key. A single transaction must be constructed satisfying the following requirements:
- Has a single or the largest input by sum signed by the sending address
- Has an output for the recipient address (the 'reference' address)
- Has an output for the exodus address
- Has one or more n-of-m OP_CHECKMULTISIG outputs each containing at least two public keys whereby the first should be the sender's public key, the second must be Mastercoin 'data package n' and the third may be 'data package n+1'
- Mastercoin 'data packages' appear in order by their sequence number
- Has all output values above the 'dust' threshold (the threshold is higher for multisig outputs)
- An additional output is permitted for the remainder of the input (the 'change' address) however this output must be addressed to the sending address
It should be clear by now that the Master Protocol can be used for activities that may be regulated or even prohibited in certain jurisdictions. Anyone working on an implementation of the Master Protocol should be very careful to warn users to know and understand the regulatory environment of their jurisdiction and country of residence in order to not break any laws. It is up to the user to know the laws of their country, and not (for instance) engage in sports betting in a jurisdiction / country where sports betting is not a legal activity.
Also, the contributors to this open source specification are not securities experts, and offer no advice or counsel on how to properly comply with securities or other regulations. This protocol is presented as a open source tool on which others can implement clients and build innovative services for the benefit of others.
That said, stable distributed currencies / smart property and the other features of this protocol will be incredibly useful in a huge number of legal applications, and even modest success of this protocol could allow early adopters (and even those who simply hold bitcoins) to greatly benefit. The Master Protocol and Mastercoins, are just neutral tools, capable of being used for good or for evil. We urge our early adopters to consider how they may use Mastercoin for good, and if they gain from its adoption, to use those funds for good. It will take a lot of work to make the good, outshine bad actors.
Placing your funds in experimental currencies is really, absurdly risky. This paper is not investment advice, and anyone predicting what will happen with experimental currencies such as those described here is indulging in the wildest sort of speculation, and that includes the speculations in the previous appendix.
Please consult your financial adviser before purchasing Mastercoins or other digital tokens (hint: they will probably tell you to RUN and not look back unless you assure them that it is money you are totally prepared to lose).
Anyone who puts their rent money or life savings into an experiment of this type is very unwise, and is risking financial ruin from this or similarly other risky enterprise.
One of the large differences between Mastercoin and Bitcoin is that there is no reference implementation available for Mastercoin which you can use to test your own implementation. The official spec, the document you hopefully just read, is open for interpretation. This makes it very difficult to make sure every implementation processes transactions the same. In order to make it easier to compare implementations and spot discrepancies every webbased Mastercoin service should ideally implement the following API calls.
GET /mastercoin_verify/addresses?currency_id=#currency_id#
[{address: 1KZmDQGzGJWYmPP9X3b7TA9dY91KBXgaG4, balance: 20.1}, {address: 1Q1sFqsi8S5DxV5hz6sWLamGBp9To93iG7, balance: 3.1}, etc..]You supply this URL a currency_id, initially 1 or 2, and it should return an JSON array of objects with two keys: address and balance. This will be a quick way to spot differences between implementations. If an other returns a different balance for two implementations a second call can be used to spot the offending transaction.
GET /mastercoin_verify/transactions/#address#?currency_id=#currency_id#
{address: 1KZmDQGzGJWYmPP9X3b7TA9dY91KBXgaG4, transactions: [{tx_hash: 5f01def181b761f1d03bcd20590c5729a47b11c68955b364add9253d7aec5eb9, valid: true, accepted_amount: nil, bought_amount: nil}, {tx_hash: 130c5175d4f3e9add03bd1d115a87b26e613293fbe3815b970f8fc830f018ebc, valid: false, accepted_amount: nil, bought_amount: nil}, etc..]} This URL takes an address and currency_id as arguments and should return an JSON object with an address and a transactions key for this given address. The transactions key should have an array of all transactions for this address and whether this implementation considers a given transaction valid or not.
In all likeliness this will capture most of the discrepancies. If this doesn't proof enough we can supply addional information like the amount transferred per transaction in the future.
For Simple Send transactions accepted_amount and bought_amount can be null values. These values are only used for Distributed Exchange transactions. The accepted amount should contain the amount that was accepted when a Purchase Offer got added to a block.
Example:
User A has a Selling Offer for 5 MSC. User B sends out a Purchase Offer for 8. It gets added to a block but since User A only had a Selling Offer for 5 the Accepted Amount for User B's Purchase Offer is now 5.
The bought amount is the total amount a user actually spends on an open Purchase Offer.
Example:
User B has a valid Purchase Offer to buy 5 MSC from User A. He sends out a transaction that actually purchases 2 MSC. At that point his Purchase Offer has an bought_amount of 2 MSC. If he decides to sent an other 3 MSC later this values gets updated to 5 MSC.
The Master Protocol is at its core a layer of functionality on top of Bitcoin, utilizing the Bitcoin network for cryptographically secured data storage. As such inherent to this approach are Bitcoin transaction fees.
In addition to transaction fees however there are costs associated with the outputs used to store transaction data for the various classes of transaction and these must be considered to reach a total cost to the end user for broadcasting a given Master Protocol message.
Each output must carry a value higher than the dust threshold (0.00005460 as of 6 Feb 2014) in order for the transaction to be considered for inclusion within a block. Class B multisig outputs are significantly larger and thus command a higher minimum output value. For the purposes of this appendix default minimum values of 0.00006 and 0.00012 respectively will be used.
The following calculations will demonstrate the perceived cost to the end-user, assuming a rate of 650 USD per BTC:
Class A
0.00006 ($0.04) - Exodus Address Output
0.00006 ($0.04) - Reference Address Output
0.00006 ($0.04) - Data Address Output
0.0001 ($0.07) - Bitcoin Transaction Fee
Total perceived cost ~$0.18 per transaction.
Class B
0.00006 ($0.04) - Exodus Address Output
0.00006 ($0.04) - Reference Address Output
0.00012 ($0.7) - Per Multisig Output
0.0001 ($0.07) - Bitcoin Transaction Fee
Total perceived cost ~$0.22 per transaction.
Each multisig output in a Class B transaction may contain two Master Protocol packets of 30 bytes each. Thus we can infer (again at 650 USD per BTC) that for every 60 bytes, we increase perceived transaction cost by ~$0.08.
The term 'perceived' cost has been applied as the Master Protocol transaction model does not 'burn' (destroy) these outputs, but rather they are redeemable by the various participants of the transaction (with the exception of the Class A data address, hence its deprecation).
In a class A transaction (note class A allows simple send only):
- The foundation (by controlling the Exodus address) may redeem the Exodus output
- The reference address may redeem the Reference output
In a class B transaction:
- The foundation may redeem the Exodus output
- The reference address may redeem the Reference output
- The sending address may redeem the Multisig output(s)
As we can see from the above, the true cost of a Master Protocol message may be less than that of the perceived cost (as for example the sender may recover some of the cost). A challenge for communication strategy will be providing awareness on this topic in a clear and simple fashion to the community.
A further consideration relates to how multisig outputs are presented in the bitcoin reference client. It is technically accurate to state that any of the addresses within a Class B multisig output can redeem, however only one of these addresses (the sending address) actually has a known private key. The bitcoin reference client however of course has no way of knowing this and so does not include unspent multisig outputs in the displayed balance.
It is envisaged that in future Master Protocol clients will 'clean up' periodically by redeeming and consolidating unspent multisig outputs.