Swarm Storage Incentives

This repository contains the smart contracts for Swarm's storage incentives.

Overview

In order to distribute to upload content to the Swarm network, batches of postage stamps are purchased by nodes. These stamps are then attached to content that is divided into 4kb chunks and then uploaded to the Swarm network. In order to distribute the proceeds from the sales of these batches, a Schelling Co-ordination Game is implemented using the smart contracts contained in this repository, in order to identify nodes storing the canonical subset of valid chunks that fall within the radius of responsibility of each node in a neighbourhood at the time of their application. Correct identification of this hash qualifies a node to apply to receive a reward comprising value arising from expired batches.

Stakes

Each storage node seeking to benefit from storage incentive rewards should stake at least the minimum stake by sending BZZ to the staking contract. This stake permits each node to participate in the Schelling game. At this stage, to keep things simple, a stake is not withdrawable. It is expected over time that neighbourhood stakes will find a homeostasis at an amount proportional to a node's expected future returns minus their running costs.

For each round of the storage rewards redistribution process, a node is chosen at random from the participants proportional to their stake density to be that round's truth teller. Nodes that agree with this "truth" are qualified to receive the entire reward for that round if they are chosen by a second random selection procedure, wherein the probability of their selection is similarly weighted by the density of their stake. Over time, all else being equal, a node will hence receive reward relative to the proportional size of their stake if they are fully participant in the Swarm protocols.

A node must have staked at least two rounds prior to their application. If a stake is updated, a node may not participate until the next two rounds have elapsed.

Current Implementation (Phase 3)

Every N blocks, at the end of the previous reveal phase, the redistribution contract selects a random round anchor which determines which neighbourhood may participate in the current round. Eligibility is determined by calculating the proximity of a node's overlay address to the round anchor. A node is eligible if their proximity order to the anchor is less than or equal to the canonical storage depth that they use to calculate their commit hash.

If eligible to participate, a node will use the chunks in its reserve to calculate a reserve commitment. This is the keccack256 hash of the first m chunk addresses when transformed using the standard hmac keyed hash function where the round anchor is used as the key. The reserve commitment should be the same for each node in a neighbourhood and represents their ability to access a full canonical reserve of chunks at the time that the anchor was selected. The nodes then combine this with a unique reveal nonce, their overlay and their current storage depth, defined as the maximum proximity order between their address and that of the furthest chunk that still falls within the node's fixed size reserve. The keccack256 hash of the concatenation of these values is known as a commit hash. This is then submitted to the blockchain during that round's commit phase.

If nodes in the neighbourhood's pull sync protocols are running as they should, each node in the neighbourhood will calculate the same reserve commitment hash and storage depth. However, since the commit hash calculation also includes a random reveal nonce in before it is hashed, each node's reserve commitment hash and storage depth is kept private during the commit phase. Once the commit phase is over, the reveal phase begins, and each participating node is expected to send another transaction to the redistribution contract with the corresponding pre-image of the hash, comprising the reserve commitment, storage depth and reveal nonce.

If the revealed reserve commitment, storage depth and reveal nonce values are found to correctly re-hash to the commit hash the node has submitted, the node is included in a procedure to select the node that will be the beneficiary of the rewards from this round. If the reveal values do not has to the submitted pre-image, the node's overlay is frozen for a number of rounds proportional to the reported storage depth, and that overlay is prevented from being able to participate until this period has elapsed.

Once the reveal phase is over, the claim phase begins. A random seed is chosen using the block.difficulty (= block.prevrandao in post-merge chains) as a source of randomness. Based on this, a node is selected as the truth teller for this round, with a probability proportional to its stake density, then, from the nodes that agree with this "truth", a beneficiary of this round's rewards is selected, with a probability similarly proportional to its stake density.

The entire amount of the total of the postage batch proceeds that have expired during this round are withdrawn from the postage stamp contract and transferred to the winner. Nodes that have revealed reserve commitments or storage depths that do not agree with the truth teller are frozen for a period longer but similarly proportioned to the truthy depth and will have to wait until unfrozen to participate again.

When the claim is submitted, the cardinality of the truthy set of applicants is used as to provide a signal to change the price of storage. If the redundancy per neighbourhood is at the desired amount (4), no action is taken and the price remains static. If it is lower, this indicates an overdemand for storage and an undersupply of storage nodes - the price per chunk per block is increased to cause batches to expire more quickly and to attract more storage nodes to the network. Conversely, if more than 4 nodes per neighbourhood apply with a truthy reserve commitment, this indicates an oversupply of storage nodes and the price is decreased to ensure the efficiency of service provision.

As the seed is chosen, the anchor for the next round is revealed. Once it has noticed it is within the neighbourhood, a node may begin calculating its reserve commitment in preparation for the upcoming commit phase, and so the cycle repeats.

Future Implementations Plan

Phase 4

Nodes will be expected to submit inclusion proofs during the claim period, which prove...

Phase 5

Nodes will be expected to submit inclusion proofs during the claim period, which prove inclusion of ...

End Phase

Relinquish admin rights...

Emergency

Deployment and Bootstrapping Procedure

...

Contents:

Smart Contracts and Metadata

This project includes the following smart contracts and their metadata:

• Smart Contracts

  • Redistribution
  • Staking Registry
  • Price Oracle
  • Postage Stamps
    • HitchensOrderStatisticsTreeLib
  • Test Token

• Metadata (Testnet,Mainnet)

  • Chain ID: Chain ID of the blockchain.
  • Network ID: Network ID.
  • ABI: Interface to communicate with smart contracts.
  • Bytecode: Compiled object code that is executed during communication with smart contract.
  • Address: Address of the deployed contract on the blockchain.
  • Block: Block height in which the transaction is mined.
  • URL: URL for analyzing the transaction.

Scripts

• Script for deploying all and individual contracts
• Script assigning roles/permissions for smart contracts
  • Redistributor role
  • Price Oracle role
  • Price Updater role

Project Setup

Prerequisites

To set up the project, you will need yarn and node.

The project has been tested with the latest node LTS (Erbium). A .nvmrc file is also provided.

Setup

To get started with this project, follow these steps:

1. Clone the repo.
2. Run yarn install at the root of the repo to install all dependencies.
3. Add a .env file in your root directory, where you'll store your sensitive information for deployment. An example file .env.example is provided for reference.

Run

Tests

• Unit Tests
  • Run yarn hardhat test to run all the tests.
  • Run yarn hardhat coverage to see the coverage of smart contracts.

Deployments

Method

All deployments and Tests are fully dependant on Hardhat Deploy library https://github.com/wighawag/hardhat-deploy and follow best practices used there

Prerequisites

Feel free to use public RPCs but if you want extra security and speed, feel free to use Infura, Alchemy or any other private RPC and add full path with your KEY to .env file

Steps

1. Run yarn hardhat compile to get all the contracts compiled.
2. Run yarn hardhat test to run all the tests.
3. Configure .env file
   • Set your WALLET_SECRET in the .env file.
   • Set your INFURA_TOKEN in the .env file.
4. To deploy all contracts and set roles:
   • Mainnet: yarn hardhat deploy --network mainnet
   • Testnet: yarn hardhat deploy --network testnet

Note can also use npx instead of yarn, so it would be 'yarn hardhat compile'. For fastest typing you can install https://hardhat.org/hardhat-runner/docs/guides/command-line-completion and then just run 'hh compile' 'hh test'

Note: If using Goerli as tesnet be aware that GAS prices are very high and maybe you will should add custom gasPrice that is very high if you want to get your picked up fast, set it in hardhat.config.ts or as options when deploying

Note: After successfully deploying to mainnet or testnet the mainnet_deployed.json and testnet_deployed.json will be automatically updated and those changes should be committed as bee node is picking them up as data that is used in nodes. This is done utilizing codegen/generate_src.sh script that is activated as github action, more on this at the bottom in Releasing section

Note: WALLET_SECRET can be Mnemonic or Private Key.

Local

• Run yarn hardhat deploy to deploy all contracts on hardhat environment(network).
• To deploy on Ganache (or other networks):
  • Add network configuration in your hardhat.config.ts.

    ganache: {
          url: 'http://localhost:8545',
          chainId: 1337,
    },
    

  • To run: yarn hardhat deploy --network ganache

Additional commands and flags:

• Make necessary changes to hardhat.config.ts.
  • List of available configs can be found here.
• Run script yarn hardhat run <script> --network <network>
  • Network: Configure network name
  • Script: Configure script name and path

Releasing

To release a new rc version, tag the commit with the -rcX suffix, where X is the release candidate number. For example, to release v0.4.0-rc1, execute the following command: git tag v0.4.0-rc1 && git push origin v0.4.0-rc1. This will generate Golang source code for the smart contracts and publish it to the ethersphere/go-storage-incentives-abi repository. It'll also generate .env file with the bytecodes and publish it to the ethersphere/docker-setup-contracts repository. The values for the Golang source code and .env file are taken from the testnet_deployed.json file, (see the Deployment section).

To release a new stable version, tag the commit without the -rcX suffix. For example, to release v0.4.0, execute the following command: git tag v0.4.0 && git push origin v0.4.0. This will generate Golang source code for the smart contracts and publish it to the ethersphere/go-storage-incentives-abi repository. The values for the Golang source code file are taken from the mainnet_deployed.json file (see the Deployment section).