Goals
Hyperledger Iroha v2 aims to be an even more simple, highly performant distributed ledger platform than Iroha v1. V2 carries on the tradition of putting on emphasis on having a library of pre-defined smart contracts in the core, so that developers do not have to write their own code to perform many tasks related to digital identity and asset management.
Background and strategic fit
Assumptions
- Users will work with provided client libraries (iOS, Android, JS).
- 3f+1 nodes are enough to tolerate f Byzantine nodes in the network.
- Iroha uses a simple data model made up of domains, peers, accounts, assets, signatories, and permissions, as shown in the figure below - all other entities are built on top of them.
Requirements
Sources
There are the following sources for all requirements:
- The main source of core structure: Iroha 2 white paper, authored by Makoto Takemiya
- List of requests from the Soramitsu projects regarding features
- Decisions made during the discussion, which are fixed in the list of RFCs
Functional
Peer to peer communication
| ID | Item | EPIC | Importance | ADR/RFC | Brief description | Notes |
|---|---|---|---|---|---|---|
| IF2-100 | Peer to Peer Network Library | MUST | Networking stack | Iroha must have a specific peer-to-peer protocol for effective communication and provided it as a detachable library. | Plain TCP\IP based protocol with SCALE as de\serialization format. | |
| IF2-101 | Transactions Time to Live | HI2-38 | MUST | Prevent replay of rejected transactions | Iroha must provide the possibility to explicitly state time-to-live (TTL) for each transaction, so the clients can set time interval in which transactions should be confirmed and put into the block store or removed from the queue by timeout. | |
| IF2-102 | Multisignature Transactions | HI2-13 | MUST | Iroha must provide the possibility to configure each account to have a list of signatories, which needs to provide their signatures to confirm the transaction. Also, Iroha should provide the possibility to perform conditional multi-signature transactions, so the conditions will automate transaction creation or signing them | ||
| IF2-103 | Transaction dependencies | NOT DEFINED | Transaction tags | (Proposed by Kamil') Iroha may provide a possibility to perform tag-based dependencies between transactions for making their sequence configurable by the client |
Blocks storage
| ID | Item | EPIC | Importance | ADR/RFC | Brief description | Notes |
|---|---|---|---|---|---|---|
| IF2-200 | World State View | MUST | Iroha must have an in-memory representation of the World State View for optimization of access and change time. | In-memory, read fast data representation of the current World's State. | ||
| IF2-201 | Kura | MUST | Iroha must have abstraction over the disk-based block storage, which will cover all validation- and world-state-view-related functionality. Iroha should have the Kura as a detachable library, so other Hyperledger solutions can easily reuse it. | Kura is a decorator on top of Disk Block Storage and provides validation and World State View synchronization functionality. | ||
| IF2-202 | Blocks Synchronization | MUST | Block Synchronization | Iroha must perform seamless synchronization of block storage between peers, so new peers or lagging ones will quickly synchronize their state with the network and join the decision-making process in consensus. | Peers periodically gossip with each other, sharing the latest block hash. If the hashes differ, then the peers discover they are out of sync and request synchronization. | |
| IF2-203 | Merkle Tree | MUST | Merkle Tree | Iroha provides a general purpose implementation of a Merkle Tree, which is used to verify the state of committed blocks and their transactions. |
Consensus
| ID | Item | EPIC | Importance | ADR/RFC | Brief description | Notes |
|---|---|---|---|---|---|---|
| I2-300 | Sumeragi | HI2-3 | MUST | Iroha must have a reliable BFT consensus of blocks between all peers, which should keep effectively prevent attacks and malfunctioning in case of (details of Sumeragi are described in the white paper) Sumeragi should be implemented as a detachable component and be available as a library, so other Hyperledger solutions can reuse it. |
Queries
| ID | Item | EPIC | Importance | ADR/RFC | Brief description | Notes |
|---|---|---|---|---|---|---|
| I2-400 | Iroha Queries | HI2-31 | MUST | Iroha must provide a set of queries, which will cover the acquisition of all client-related data about all existing entities. | Iroha Queries provide information about World State View based on client permissions. |
Smart Contracts
| ID | Item | EPIC | Importance | ADR/RFC | Brief description | Notes |
|---|---|---|---|---|---|---|
| IF2-500 | Iroha Special Instructions mechanism | MUST | Iroha must provide a possibility to create various instructions to cover | |||
| IF2-501 | Out of the box set of Iroha Special Instructions | MUST | Several Tiers of Iroha Special Instructions provide:
| |||
| IF2-502 | Permissions | HI2-36 | MUST | Permissions and Event Listeners | Permissions in Iroha implemented based on Assets and Iroha Special Instructions. | |
| IF2-503 | Triggers | HI2-37 | COULD | Permissions and Event Listeners | Triggers in Iroha implemented based on Assets and Iroha Special Instructions. | |
| IF2-504 | Domain-Specific Language | COULD | DSL Structure | Custom Iroha Special Instructions and usage of the full set of Iroha Special Instructions should be easy for developers. | ||
| IF2-505 | Advanced Permissions Model | COULD | Expand Iroha Permission model | Full-fledged rights model in Iroha will greatly reduce the amount of server development for Iroha-based applications. |
Modules
| ID | Item | EPIC | Importance | ADR/RFC | Notes |
|---|---|---|---|---|---|
| IF2-600 | Bridge | MUST | Bridges | The mechanism for communication between third-party blockchains. | |
| DEX | MUST | DEX Requirements and Design | The ability to exchange assets between accounts. |
Maintenance
| ID | Item | EPIC | Importance | ADR/RFC | Brief description | Notes |
|---|---|---|---|---|---|---|
| IF2-700 | Maintenance Endpoint | MUST | Maintenance Endpoint | Iroha must provide a maintenance endpoint, which can be used for performing operations (control over node status), requesting statistics and health information and subscribing on the updates (new blocks, transaction status changes, etc.). |
Clients
| ID | Item | EPIC | Importance | ADR/RFC | Notes |
|---|---|---|---|---|---|
| HTTP API | MUST | HTTP API for Clients | Because of clients restrictions decision about HTTP API was pushed forward. | ||
| IF2-800 | Rust Client Library | HI2-32 | MUST | Iroha Client encapsulates network-related functionality and provides "local" Rust Interface for:
| |
| IF2-801 | `no-std` client | ??? | Migration from Strings | ||
| IF2-802 | Mobile SDK | MUST | |||
| IF2-803 | Web SDK | MUST | Web API |
Non-Functional
Security
- Support configurable crypto algorithms
- Support for server-side HSM integration
- Security and consistency improvements
- Encapsulation of crypto-related functionality
- Transport Layer Security Configuration
Target Platforms
Iroha deployment should support GNU/Linux, macOS and Windows machines with x86 and Arm64 CPUs.
Transactions Processing
Iroha Peer should be able to process 20,000 transactions per second.
Blocks Processing
Iroha should be able to commit a new block every 3 seconds.
Development related
Benchmarks
Maintenance
- Logging -
- Service Discovery
Continuous Delivery
- Docker images publish
- Binary and documentation publish
Longevity Stand
Distributed testing
- 10 servers, each on a different machine and in different geographies.
- Run data through them for several minutes to really get some meaningful data.
- Here is what each peer should do:
- sync with peers about the latest blocks
- gossip about (forward) transactions that are pending that they have
- propose or vote on a block (as part of consensus)
- ping and verify peers as part of the Hijiri reputation system (basically something like eigentrust++)
- share time information as part of a p2p network time service
User interaction and design
Questions
Below is a list of questions to be addressed as a result of this requirements document:
| Question | Outcome |
|---|---|
Not Doing
- Genesis Block