v1.6.1

Install

To install Decrediton desktop wallet, download, uncompress, and run Decrediton Linux or Decrediton macOS or Decrediton Windows.

To install the command-line tools, please see dcrinstall.

See decred-v1.6.1-manifest.txt and the other manifest files for SHA-256 hashes and the associated .asc signature files to confirm those hashes.

See README.md for more info on verifying the files.

Skip to downloads

Contents

• dcrd
• dcrwallet
• Decrediton
• dcrdex

dcrd v1.6.1

This is a patch release of dcrd which includes the following changes:

• Correct a hard to hit issue where connections might not be reestablished after a network outage under some rare circumstances
• Allow stakeholders to make use of the staking system to force proof-of-work miners to upgrade to the latest version so voting on the new consensus changes can commence

Changelog

This patch release consists of 3 commits from 1 contributor which total to 3 files changed, 30 additional lines of code, and 9 deleted lines of code.

All commits since the last release may be viewed on GitHub here.

Protocol and Network

• server: Notify block mgr later and track ntfn (decred/dcrd#2588)
• server: Force PoW upgrade to v8 (decred/dcrd#2597)

Misc

• release: Bump for 1.6.1 (decred/dcrd#2600)

Code Contributors (alphabetical order)

• Dave Collins

dcrwallet v1.6.1

This release focuses on fixing issues with the new VSP fee payments and account mixing.

New Features

• A WalletServer.SetVspdVoteChoice gRPC method was added, allowing clients to update the agenda preferences for the new VSP software.

Bug Fixes

• An additional transaction may be created now when an account does not have enough UTXOs to pay for both a ticket and a VSP fee. This avoids insufficient balance errors where possible and prevents the user from needing to split a UTXO themselves.

• Several issues causing double spends when dealing with unpublished transactions were corrected. This improves the reliability of paying the VSP fee.

• Account balances no longer report the outputs of unpublished transactions as spendable with minconf=0. Instead, these balances are added to the unconfirmed balance.

• Account and output mixing now considers the required fee necessary when selecting which common output amount and output count to mix with. This fixes mixing for some outputs which are currently being rejected by the CoinShuffle++ server due to not paying enough of the required transaction fee.

• The signrawtransaction JSON-RPC method was changed to return an error if the transaction being signed has no inputs.

• The salsa20 and blake2b dependencies were updated to prevent possible memory corruption caused by smashing the SP register in optimized assembly implementations.

Changelog

All commits since the last release may be viewed on GitHub here.

Code Contributors (alphabetical order)

• Josh Rickmar

Decrediton v1.6.1

This patch release fixes several issues discovered in the v1.6.0 release.

Most changes are focused on improving the staking experience with the new VSP system: unexpected insufficient balance error is fixed, successes and failures of various staking operations are better reported now, setting consensus vote choices on the new VSP was implemented.

Updates

• Consensus change voting is now working as expected. When a user sets their vote choice, it is updated in their local wallet and also sent to any legacy VSP. Every live ticket they have assigned with a new VSP is updated as well.

• Due to the way the coins (UTXOs) are handled when purchasing tickets, there is a possibility of the underlying dcrwallet purchasing fewer tickets than what the user requested. This condition is now explained with a better message, to help the user understand why, for example, they only got 1 ticket when trying to buy 2.

• Labels on the Staking tab have been updated to make things more clear with the new tickets and the old tickets.

• An initial Traditional Chinese translation was completed by @smartwojak and verified by long-standing community member Hugo Chang (@changhugo).

• Running or attempting multiple things at the same time is no longer allowed to avoid possible issues or unexpected errors. For instance, when the mixer is running, users may not purchase tickets or run the autobuyer, and vice versa. To perform an action, the user needs to turn off a running activity before proceeding. Several tooltips have been added to make the user aware of the situation.

• Loading indicators have been added to various buttons related to ticket purchasing, to indicate that the user should wait for a long-running operation (like mixed ticket purchasing) to complete.

• Success and failure messages have been added to various new ticket purchasing actions. Now users will be shown a message when they successfully complete (or receive errors for) the following actions: verify that visible tickets are assigned to VSPs and have their fees paid (Process Managed), discover tickets not yet assigned to a VSP and pay their fees (Process Unmanaged), and sync failed VSP tickets.

Bug Fixes

• Added a timeout when not receiving VSP status response within 5 seconds.

• Transaction history filtering has been fixed and now allows to select multiple types of transactions at once.

• Tickets will now show as "Processing", "Error" or "Paid" shortly after purchase. Previously they would be shown as "Solo" until a restart or another block was mined.

• Added explicit wallet lock calls to ensure that wallet is locked after mixing or ticket autobuyer requests.

• There were a few reports of incorrectly created legacy ticket purchases due to a still unknown cause. To work-around this we've added sanity checks prior to purchase request to dcrwallet to avoid any potential malformed requests from being sent. This won't solve the core issue, but should at least notify users of something wrong occuring and give us data to investigate further.

Changelog

All commits since the last release may be viewed on GitHub here.

Code Contributors (alphabetical order)

• Alex Yocom-Piatt
• Amir Massarwa
• bgptr
• Guilherme Marques
• JoeGruffins
• Matheus Degiovani
• Scott Christian
• smartwojak
• Victor Oliveira

dcrdex v0.1.5

This patch release provides several important bug fixes.

Please read the initial release (v0.1.0) notes for important information and instructions.

Client (dexc)

Features and Improvements

• The user's account ID is now logged on connection and authentication with a DEX server. (8ce328)

Fixes

• Fix a possible panic when reconfiguring a wallet that is not connected. (dfe4cd)

• When resuming trades on startup and login, counterparty contract audits now retry repeatedly, as is the case when an audit request is initially received. This prevents a match from being incorrectly revoked on startup if the wallet/node fails to locate the counterparty contract immediately. (dfe4cd)

• The client's database subsystem is always started first and stopped last. This is a prerequisite for the following wallet lock-on-shutdown change. (b4ef3f)

• On shutdown of client Core, the wallets are now locked even if the PromptShutdown function is not used. This does not affect dexc users, only direct Go consumers of the client/core.Core type. (70044e)

• Fix a possible interruption of the DEX reconnect loop if the config response timed out. (4df683)

• Update the crypto/x/blake2 dependency to prevent silent memory corruption from the hash function's assembly code. (c67af3)

• Handle orders that somehow lose their funding coins. Previously, such orders would forever be logged at startup but never retired, and any matches from such orders that required swap negotiation of other recovery would have been improperly abandoned. (a7b5aa)

Server (dcrdex)

There are no substantive server changes, just a few logging improvements.

Code Summary

11 commits, 13 files changed, 564 insertions(+), and 254 deletions(-)

decred/dcrdex@v0.1.4...v0.1.5

3 contributors

• Brian Stafford (@buck54321...

v1.6.0

Install

To install the command line tools, please see dcrinstaller.

To install decrediton download, uncompress, and run decrediton Linux or decrediton macOS or decrediton Windows.

See manifest-v1.6.0.txt, and the package specific manifest files for sha256 sums and the associated .asc files to confirm those shas.

See README.md for more info on verifying the files.

Skip to downloads

Contents

• dcrd
• dcrwallet
• decrediton
• dcrlnd
• dcrdex

dcrd v1.6.0

This release of dcrd introduces a large number of updates. Some of the key highlights are:

• A new consensus vote agenda which allows the stakeholders to decide whether or not to activate support for a decentralized treasury
• Aggregate fee transaction selection in block templates (Child Pays For Parent)
• Improved peer discovery via HTTPS seeding with filtering capabilities
• Major performance enhancements for signature validation and other cryptographic operations
• Approximately 15% less overall resident memory usage
• Proactive signature cache eviction
• Improved support for single-party Schnorr signatures
• Ticket exhaustion prevention
• Various updates to the RPC server such as:
  • A new method to retrieve the current treasury balance
  • A new method to query treasury spend transaction vote details
• Infrastructure improvements
• Quality assurance changes

For those unfamiliar with the voting process in Decred, all code needed in order to support a decentralized treasury is already included in this release, however it will remain dormant until the stakeholders vote to activate it.

For reference, the decentralized treasury work was originally proposed and approved for initial implementation via the following Politeia proposal:

• Decentralized Treasury Consensus Change

The following Decred Change Proposal (DCP) describes the proposed changes in detail and provides a full technical specification:

• DCP0006

It is important for everyone to upgrade their software to this latest release even if you don't intend to vote in favor of the agenda.

Downgrade Warning

The database format in v1.6.0 is not compatible with previous versions of the software. This only affects downgrades as users upgrading from previous versions will see a one time database migration.

Once this migration has been completed, it will no longer be possible to downgrade to a previous version of the software without having to delete the database and redownload the chain.

The database migration typically takes about 5 to 10 minutes on HDDs and 2 to 4 minutes on SSDs.

Notable Changes

Decentralized Treasury Vote

A new vote with the id treasury is now available as of this release. After upgrading, stakeholders may set their preferences through their wallet or Voting Service Provider's (VSP) website.

The primary goal of this change is to fully decentralize treasury spending so that it is controlled by the stakeholders via ticket voting.

See the initial Politeia proposal for more details.

Aggregate Fee Block Template Transaction Selection (Child Pays For Parent)

The transactions that are selected for inclusion in block templates that Proof-of-Work miners solve now prioritize the overall fees of the entire transaction ancestor graph.

This is beneficial for both miners and end users as it:

• Helps maximize miner profit by ensuring that unconfirmed transaction chains with higher aggregate fees are given priority over others with lower aggregate fees
• Provides a mechanism for users to increase the priority of an unconfirmed transaction by spending its outputs with another transaction that pays higher fees

This is commonly referred to as Child Pays For Parent (CPFP) as the spending ("child") transaction is able to increase the priority of the spent ("parent") transaction.

HTTPS Seeding

The initial bootstrap process that contacts seeders to discover other nodes to connect to now uses a REST-based API over HTTPS.

This change will be imperceptible for most users, with the exception that it accelerates the process of finding suitable candidate nodes that support desired services, particularly in the case of recently-introduced services that have not yet achieved widespread adoption on the network.

The following are some key benefits of HTTPS seeders over the previous DNS-based seeders:

• Support for non-standard ports
• Advertisement of supported service
• Better scalability both in terms of network load and new features
• Native support for TLS-secured communication channels
• Native support for proxies which allows the use of anonymous overlay networks such as Tor and I2P
• No need for a large DNSSEC dependency surface
• Uses better audited infrastructure
• More secure
• Increases flexibility

Signature Validation And Other Crypto Operation Optimizations

The underlying crypto code has been reworked to significantly improve its execution speed and reduce the number of memory allocations. While this has more benefits than enumerated here, probably the most important ones for most stakeholders are:

• Improved vote times since blocks and transactions propagate more quickly throughout the network
• The initial sync process is around 15% faster

Proactive Signature Cache Eviction

Signature cache entries that are nearly guaranteed to no longer be useful are now immediately and proactively evicted resulting in overall faster validation during steady state operation due to fewer cache misses.

The primary purpose of the cache is to avoid double checking signatures that are already known to be valid.

Orphan Transaction Relay Policy Refinement

Transactions that spend outputs which are not known to nodes relaying them, known as orphan transactions, now have the same size restrictions applied to them as standard non-orphan transactions.

This ensures that transactions chains are not artificially hindered from relaying regardless of the order they are received.

In order to keep memory usage of the now potentially larger orphan transactions under control, more intelligent orphan eviction has been implemented and the maximum number of allowed orphans before random eviction occurs has been lowered.

These changes, in conjunction with other related changes, mean that nodes are better about orphan transaction management and thus missing ancestors will typically either be broadcast or mined fairly quickly resulting in fewer overall orphans and smaller actual run-time orphan pools.

Ticket Exhaustion Prevention

Mining templates that would lead to the chain becoming unrecoverable due to inevitable ticket exhaustion will no longer be generated.

This is primarily aimed at the testing networks, but it could also theoretically affect the main network in some far future if the demand for tickets were to ever dry up for some unforeseen reason.

New Initial State Protocol Messages (getinitstate/initstate)

This release introduces a pair of peer-to-peer protocol messages named getinitstate and initstate which support querying one or more pieces of information that are useful to acquire when a node first connects in a consolidated fashion.

Some examples of the aforementioned information are the mining state as of the current tip block and, with the introduction of the decentralized treasury, any outstanding treasury spend transactions that are being voted on.

Mining State Protocol Messages Deprecated (getminings/minings)

Due to the addition of the previously-described initial state peer-to-peer protocol messages, the getminings and minings protocol messages are now deprecated. Use the new getinitstate and initstate messages with the headblocks and headblockvotes state types instead.

RPC Server Changes

The RPC server version as of this release is 6.2.0.

New Treasury Balance Query RPC (gettreasurybalance)

A new RPC named gettreasurybalance is now available to query the current balance of the decentralized treasury. Please note that this requires the decentralized treasury vote to pass and become active, so it will return an appropriate error indicating the decentralized treasury is inactive until that time.

See the gettreasurybalance JSON-RPC API Documentation for API details.

New Treasury Spend Vote Query RPC (gettreasuryspendvotes)

A new RPC named gettreasuryspendvotes is now available to query vote information about one or more treasury spend transactions. Please note that this requires the decentralized treasury vote to pass and become active to produce a meaningful result since treasury spend transactions are invalid until that time.

See the gettreasuryspendvotes JSON-RPC API Documentation for API details.

New Force Mining Template Regeneration RPC (regentemplate)

A new RPC nam...

v1.6.0-rc5

add decrediton v1.5.2 rel notes (#129)

v1.6.0-rc4

add decrediton v1.5.2 rel notes (#129)

v1.6.0-rc3

add decrediton v1.5.2 rel notes (#129)

v1.6.0-rc2

add decrediton v1.5.2 rel notes (#129)

v1.6.0-rc1

2020-10-21

Install

To install the command line tools, please see dcrinstaller.
To install decrediton download, uncompress, and run decrediton Linux or decrediton macOS or decrediton Windows.

See manifest-v1.6.0-rc1.txt, and the package specific manifest files for sha256 sums and the associated .asc files to confirm those shas.

See README.md for more info on verifying the files.

Contents

• dcrd
• dcrwallet
• decrediton
• dcrlnd

dcrd v1.6.0-rc1

This release of dcrd introduces a large number of updates. Some of the key highlights are:

• A new consensus vote agenda which allows the stakeholders to decide whether or not to activate support for a decentralized treasury
• Aggregate fee transaction selection in block templates (Child Pays For Parent)
• Improved peer discovery via HTTPS seeding with filtering capabilities
• Major performance enhancements for signature validation and other cryptographic operations
• Approximately 15% less overall resident memory usage
• Proactive signature cache eviction
• Improved support for single-party Schnorr signatures
• Ticket exhaustion prevention
• Various updates to the RPC server such as:
  • A new method to retrieve the current treasury balance
  • A new method to query treasury spend transaction vote details
• Infrastructure improvements
• Quality assurance changes

For those unfamiliar with the voting process in Decred, all code needed in order to support a decentralized treasury is already included in this release, however it will remain dormant until the stakeholders vote to activate it.

For reference, the decentralized treasury work was originally proposed and approved for initial implementation via the following Politeia proposal:

• Decentralized Treasury Consensus Change

The following Decred Change Proposal (DCP) describes the proposed changes in detail and provides a full technical specification:

• DCP0006

It is important for everyone to upgrade their software to this latest release even if you don't intend to vote in favor of the agenda.

Downgrade Warning

The database format in v1.6.0 is not compatible with previous versions of the software. This only affects downgrades as users upgrading from previous versions will see a one time database migration.

Once this migration has been completed, it will no longer be possible to downgrade to a previous version of the software without having to delete the database and redownload the chain.

The database migration typically takes about 5 to 10 minutes on HDDs and 2 to 4 minutes on SSDs.

Notable Changes

Decentralized Treasury Vote

A new vote with the id treasury is now available as of this release. After upgrading, stakeholders may set their preferences through their wallet or Voting Service Provider's (VSP) website.

The primary goal of this change is to fully decentralize treasury spending so that it is controlled by the stakeholders via ticket voting.

See the initial Politeia proposal for more details.

Aggregate Fee Block Template Transaction Selection (Child Pays For Parent)

The transactions that are selected for inclusion in block templates that Proof-of-Work miners solve now prioritize the overall fees of the entire transaction ancestor graph.

This is beneficial for both miners and end users as it:

• Helps maximize miner profit by ensuring that unconfirmed transaction chains with higher aggregate fees are given priority over others with lower aggregate fees
• Provides a mechanism for users to increase the priority of an unconfirmed transaction by spending its outputs with another transaction that pays higher fees

This is commonly referred to as Child Pays For Parent (CPFP) as the spending ("child") transaction is able to increase the priority of the spent ("parent") transaction.

HTTPS Seeding

The initial bootstrap process that contacts seeders to discover other nodes to connect to now uses a REST-based API over HTTPS.

This change will be imperceptible for most users, with the exception that it accelerates the process of finding suitable candidate nodes that support desired services, particularly in the case of recently-introduced services that have not yet achieved widespread adoption on the network.

The following are some key benefits of HTTPS seeders over the previous DNS-based seeders:

• Support for non-standard ports
• Advertisement of supported service
• Better scalability both in terms of network load and new features
• Native support for TLS-secured communication channels
• Native support for proxies which allows the use of anonymous overlay networks such as Tor and I2P
• No need for a large DNSSEC dependency surface
• Uses better audited infrastructure
• More secure
• Increases flexibility

Signature Validation And Other Crypto Operation Optimizations

The underlying crypto code has been reworked to significantly improve its execution speed and reduce the number of memory allocations. While this has more benefits than enumerated here, probably the most important ones for most stakeholders are:

• Improved vote times since blocks and transactions propagate more quickly throughout the network
• The initial sync process is around 15% faster

Proactive Signature Cache Eviction

Signature cache entries that are nearly guaranteed to no longer be useful are now immediately and proactively evicted resulting in overall faster validation during steady state operation due to fewer cache misses.

The primary purpose of the cache is to avoid double checking signatures that are already known to be valid.

Orphan Transaction Relay Policy Refinement

Transactions that spend outputs which are not known to nodes relaying them, known as orphan transactions, now have the same size restrictions applied to them as standard non-orphan transactions.

This ensures that transactions chains are not artificially hindered from relaying regardless of the order they are received.

In order to keep memory usage of the now potentially larger orphan transactions under control, more intelligent orphan eviction has been implemented and the maximum number of allowed orphans before random eviction occurs has been lowered.

These changes, in conjunction with other related changes, mean that nodes are better about orphan transaction management and thus missing ancestors will typically either be broadcast or mined fairly quickly resulting in fewer overall orphans and smaller actual run-time orphan pools.

Ticket Exhaustion Prevention

Mining templates that would lead to the chain becoming unrecoverable due to inevitable ticket exhaustion will no longer be generated.

This is primarily aimed at the testing networks, but it could also theoretically affect the main network in some far future if the demand for tickets were to ever dry up for some unforeseen reason.

New Initial State Protocol Messages (getinitstate/initstate)

This release introduces a pair of peer-to-peer protocol messages named getinitstate and initstate which support querying one or more pieces of information that are useful to acquire when a node first connects in a consolidated fashion.

Some examples of the aforementioned information are the mining state as of the current tip block and, with the introduction of the decentralized treasury, any outstanding treasury spend transactions that are being voted on.

Mining State Protocol Messages Deprecated (getminings/minings)

Due to the addition of the previously-described initial state peer-to-peer protocol messages, the getminings and minings protocol messages are now deprecated. Use the new getinitstate and initstate messages with the headblocks and headblockvotes state types instead.

RPC Server Changes

The RPC server version as of this release is 6.1.2.

New Treasury Balance Query RPC (gettreasurybalance)

A new RPC named gettreasurybalance is now available to query the current balance of the decentralized treasury. Please note that this requires the decentralized treasury vote to pass and become active, so it will return an appropriate error indicating the decentralized treasury is inactive until that time.

See the gettreasurybalance JSON-RPC API Documentation for API details.

New Treasury Spend Vote Query RPC (gettreasuryspendvotes)

A new RPC named gettreasuryspendvotes is now available to query vote information about one or more treasury spend transactions. Please note that this requires the decentralized treasury vote to pass and become active to produce a meaningful result since treasury spend transactions are invalid until that time.

See the gettreasuryspendvotes JSON-RPC API Documentation for API details.

New Force Mining Template Regeneration RPC (regentemplate)

A new ...

v1.5.2

2020-08-27

Install

To install the command line tools, please see dcrinstaller.
To install decrediton download, uncompress, and run decrediton Linux or decrediton macOS or decrediton Windows.

See decred-v1.5.2-manifest.txt, and the package specific manifest files for sha256 sums and the associated .asc files to confirm those shas.

See README.md for more info on verifying the files.

Contents

• dcrd

dcrd v1.5.2

This is a patch release of dcrd to address a potential denial of service vector.

Changelog

This patch release consists of 5 commits from 2 contributors which total to 4 files changed, 114 additional lines of code, and 20 deleted lines of code.

All commits since the last release may be viewed on GitHub here.

Protocol and network:

• blockmanager: handle notfound messages from peers (decred/dcrd#2344)
• blockmanager: limit the requested maps (decred/dcrd#2344)
• server: increase ban score for notfound messages (decred/dcrd#2344)
• server: return whether addBanScore disconnected the peer (decred/dcrd#2344)

Misc:

• release: Bump for 1.5.2(decred/dcrd#2345)

Code Contributors (alphabetical order):

• Dave Collins
• David Hill

v1.5.1

2019-01-28

Install

To install the command line tools, please see dcrinstaller.
To install decrediton download, uncompress, and run decrediton Linux or decrediton macOS or decrediton Windows.

See decred-v1.5.1-manifest.txt, and the package specific manifest files for sha256 sums and the associated .asc files to confirm those shas.

See README.md for more info on verifying the files.

Contents

• dcrd
• dcrwallet
• decrediton

dcrd v1.5.1

This is a patch release of dcrd to address a minor memory leak with authenticated RPC websocket clients on intermittent connections. It also updates the dcrctl utility to include the new auditreuse dcrwallet command.

Changelog

This patch release consists of 4 commits from 3 contributors which total to 4 files changed, 27 additional lines of code, and 6 deleted lines of code.

All commits since the last release may be viewed on GitHub here.

RPC:

• rpcwebsocket: Remove client from missed maps (decred/dcrd#2049)
• rpcwebsocket: Use nonblocking messages and ntfns (decred/dcrd#2050)

dcrctl utility changes:

• dcrctl: Update dcrwallet RPC types package (decred/dcrd#2051)

Misc:

• release: Bump for 1.5.1(decred/dcrd#2052)

Code Contributors (alphabetical order):

• Dave Collins
• Josh Rickmar
• Matheus Degiovani

dcrwallet v1.5.1

This release contains bug fixes and minor feature additions. A comprehensive list of improvements and bug fixes follows.

New features

• An auditreuse JSON-RPC method was added. This method reports all transactions that reuse an output address, excluding votes and
  revocations which must use the committed address from a ticket. An optional block height parameter may be provided to only search for
  reuse following a block.

• The createrawtransaction JSON-RPC method was implemented directly. This allows users of the SPV syncing mode to perform the call, rather than the call erroring due to no RPC passthrough to a dcrd JSON-RPC server.

Other improvements

• The --csppserver.ca option is now expanded with ~ and environment variables.

• The sample config has been updated with options related to CoinShuffle++.

Bug fixes

• Duplicate logs for insufficient balance errors during automated ticketbuying have been silenced.

• The gRPC method TicketBuyerV2Service.RunTicketBuyer contained a regression causing all change to be created for only the default (first) account. A fix was made to restore the previous behavior, where change is created for the source account.

• An address reuse bug caused by resetting child indexes backwards after address and account discovery was corrected. It was possible
  for this bug to be hit any time network synchronization had to be restarted (e.g. the dcrd JSON-RPC link was lost), because address discovery would always occur on resync.

• A shutdown hang of the dcrwallet process following a panic in a JSON-RPC handler was fixed with improved synchronization code.

• A data race in the signrawtransaction JSON-RPC method was corrected.

• A memory leak in the JSON-RPC websocket client to dcrd was fixed. This bug caused excessive memory usage by retaining every unmarshaled response in memory for the lifetime of the websocket connection.

• Extended pubkeys imported via the importxpub JSON-RPC method may now be used immediately rather than requiring a restart of the process.

Changelog

All commits since the last release may be viewed on GitHub here.

decrediton v1.5.1

This patch release for decrediton mainly focuses on patching various issues that were found during public usage. We have also included an update to the QR code that shows a basic DCR logo within.

New Features

• The QR Code generated for addresses to receive funds in Decrediton now include a blue/green DCR logo in the center. Functionally, this will be no different than before. (#2385)

Bug Fixes

• Double notifications were being shown when sending transactions (#2375)

• Allow for the second instance warning to be closed and quit the application. (#2394)

• Various typos and spelling fixes. (#2383, #2400, #2395)

• The number of active tickets on the overview was not showing correctly while in SPV wallets. (#2389)

• Prevent gap exhaustion during change generation. (#2358)

• Disable various elements from being selectable. (#2388)

Changelog

All commits since the last release may be viewed on GitHub here.

v1.5.0

2019-12-16

Install

To install the command line tools, please see dcrinstaller.
To install decrediton download, uncompress, and run decrediton Linux or decrediton macOS or decrediton Windows.

See manifest-v1.5.0.txt, and the package specific manifest files for sha256 sums and the associated .asc files to confirm those shas.

See README.md for more info on verifying the files.

Contents

• dcrd
• dcrwallet
• decrediton
• dcrlnd

dcrd v1.5.0

This release of dcrd introduces a large number of updates. Some of the key highlights are:

• A new consensus vote agenda which allows the stakeholders to decide whether or not to activate support for block header commitments
• More efficient block filters
• Significant improvements to the mining infrastructure including asynchronous work notifications
• Major performance enhancements for transaction script validation
• Automatic external IP address discovery
• Support for IPv6 over Tor
• Various updates to the RPC server such as:
  • A new method to query information about the network
  • A method to retrieve the new version 2 block filters
  • More calls available to limited access users
• Infrastructure improvements
• Quality assurance changes

For those unfamiliar with the voting process in Decred, all code in order to support block header commitments is already included in this release, however its enforcement will remain dormant until the stakeholders vote to activate it.

For reference, block header commitments were originally proposed and approved for initial implementation via the following Politeia proposal:

• Block Header Commitments Consensus Change

The following Decred Change Proposal (DCP) describes the proposed changes in detail and provides a full technical specification:

• DCP0005

It is important for everyone to upgrade their software to this latest release even if you don't intend to vote in favor of the agenda.

Downgrade Warning

The database format in v1.5.0 is not compatible with previous versions of the software. This only affects downgrades as users upgrading from previous versions will see a one time database migration.

Once this migration has been completed, it will no longer be possible to downgrade to a previous version of the software without having to delete the database and redownload the chain.

Notable Changes

Block Header Commitments Vote

A new vote with the id headercommitments is now available as of this release. After upgrading, stakeholders may set their preferences through their wallet or Voting Service Provider's (VSP) website.

The primary goal of this change is to increase the security and efficiency of lightweight clients, such as Decrediton in its lightweight mode and the dcrandroid/dcrios mobile wallets, as well as add infrastructure that paves the way for several future scalability enhancements.

A high level overview aimed at a general audience including a cost benefit analysis can be found in the
Politeia proposal.

In addition, a much more in-depth treatment can be found in the motivation section of DCP0005.

Version 2 Block Filters

The block filters used by lightweight clients, such as SPV (Simplified Payment Verification) wallets, have been updated to improve their efficiency,
ergonomics, and include additional information such as the full ticket commitment script. The new block filters are version 2. The older version 1 filters are now deprecated and scheduled to be removed in the next release, so consumers should update to the new filters as soon as possible.

An overview of block filters can be found in the block filters section of DCP0005.

Also, the specific contents and technical specification of the new version 2 block filters is available in the version 2 block filters section of DCP0005.

Finally, there is a one time database update to build and store the new filters for all existing historical blocks which will likely take a while to complete (typically around 8 to 10 minutes on HDDs and 4 to 5 minutes on SSDs).

Mining Infrastructure Overhaul

The mining infrastructure for building block templates and delivering the work to miners has been significantly overhauled to improve several aspects as follows:

• Support asynchronous background template generation with intelligent vote propagation handling
• Improved handling of chain reorganizations necessary when the current tip is unable to obtain enough votes
• Current state synchronization
• Near elimination of stale templates when new blocks and votes are received
• Subscriptions for streaming template updates

The standard getwork RPC that PoW miners currently use to perform the mining process has been updated to make use of this new infrastructure, so existing PoW miners will seamlessly get the vast majority of benefits without requiring any updates.

However, in addition, a new notifywork RPC is now available that allows miners to register for work to be delivered asynchronously as it becomes available via a WebSockets work notification. These notifications include the same information that getwork provides along with an additional reason parameter which allows the miners to make better decisions about when they should instruct workers to discard the current template immediately or should be allowed to finish their current round before being provided with the new template.

Miners are highly encouraged to update their software to make use of the new asynchronous notification infrastructure since it is more robust, efficient, and faster than polling getwork to manually determine the aforementioned conditions.

The following is a non-exhaustive overview that highlights the major benefits of the changes for both cases:

• Requests for updated templates during the normal mining process in between tip changes will now be nearly instant instead of potentially taking several seconds to build the new template on the spot
• When the chain tip changes, requesting a template will now attempt to wait until either all votes have been received or a timeout occurs prior to handing out a template which is beneficial for PoW miners, PoS miners, and the network as a whole
• PoW miners are much less likely to end up with template with less than the max number of votes which means they are less likely to receive a reduced subsidy
• PoW miners will be much less likely to receive stale templates during chain tip changes due to vote propagation
• PoS voters whose votes end up arriving to the miner slightly slower than the minimum number required are much less likely to have their votes excluded despite having voted simply due to propagation delay

PoW miners who choose to update their software, pool or otherwise, to make use of the asynchronous work notifications will receive additional benefits such as:

• Ability to start mining a new block sooner due to receiving updated work as soon as it becomes available
• Immediate notification with new work that includes any votes that arrive late
• Periodic notifications with new work that include new transactions only when there have actually been new transaction
• Simplified interface code due to removal of the need for polling and manually checking the work bytes for special cases such as the number of votes

NOTE: Miners that are not rolling the timestamp field as they mine should ensure their software is upgraded to roll the timestamp to the latest timestamp each time they hand work out to a miner. This helps ensure the block timestamps are as accurate as possible.

Transaction Script Validation Optimizations

Transaction script validation has been almost completely rewritten to significantly improve its speed and reduce the number of memory allocations. While this has many more benefits than enumerated here, probably the most important ones for most stakeholders are:

• Votes can be cast more quickly which helps reduce the number of missed votes
• Blocks are able to propagate more quickly throughout the network, which in turn further improves votes times
• The initial sync process is around 20-25% faster

Automatic External IP Address Discovery

In order for nodes to fully participate in the peer-to-peer network, they must be publicly accessible and made discoverable by advertising their external IP address. This is typically made slightly more complicated since most users run their nodes on networks behind Network Address Translation (NAT).

Previously, in addition to configuring the network firewall and/or router to allow inbound connections to port 9108 and forwarding the port to t...