Hyperledger Fabric + Solana

Prerequisites

• Docker & Docker Compose
• Node.js and npm
• Rust toolchain
• Solana CLI
• Anchor CLI

Architecture Overview

The key insight is that Fabric handles encryption/decryption and signature verification, while Solana provides transparent vote recording and state management.

┌─────────────────┐      ┌─────────────────┐     ┌─────────────────┐
│     User        │      │   Fabric HLF    │     │     Solana      │
│  (Solana Key)   │      │   (Chaincode)   │     │    (Program)    │
└─────────────────┘      └─────────────────┘     └─────────────────┘
         │                         │                        │
         │─── register(sig) —─────▶│                        │
         │◄── DH pubkey ─—─────────│                        │
         │                         │                        │
         │─── vote(option,sig) ───▶│                        │
         │                         │─── encrypted vote ────▶│
         │                         │                        │
         │─── count() ────────────▶│                        │
         │◄── results ─────────────│                        │

Flow: Register → Vote (encrypted in HLF) → Record (in Solana) → Count (decrypt in HLF)

Mermaid Diagram

sequenceDiagram
  participant User
  participant API
  participant Solana
  participant Fabric
  
  Note over Fabric: initializeTrustedParty() creates DH keypair
  
  User->>Fabric: registerUser(solanaAddress, message, signature)
  Note right of Fabric: Verify signature<br/>Generate user DH keypair
  Fabric-->>User: User DH Public Key
  
  User->>API: createPoll(pollId, options)
  API->>Fabric: createPoll(hlfPollId, creator, options)
  API->>Solana: createPoll(pollId, options, hlfPollId)
  
  User->>API: submitVote(pollId, voteOption)
  API->>Fabric: submitVote(hlfPollId, voterAddress, voteOption, message, signature)
  Note right of Fabric: Verify signature<br/>Check duplicates<br/>Encrypt vote with shared secret<br/>(user pubkey + trusted party privkey)
  Fabric-->>API: voteId
  API->>Solana: vote(pollId, option, hlfVoteId)
  Solana-->>API: Confirm transaction
  
  User->>API: countVotes(pollId)
  API->>Fabric: countVotes(hlfPollId)
  Note right of Fabric: Decrypt votes using shared secrets<br/>Tally results
  Fabric-->>API: {OptionA: count, OptionB: count}
  API-->>User: Results

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QuickStart

To get the project up and running quickly, follow these steps in two separate terminal windows.

• Terminal 1 (Hyperledger Fabric & Chaincode)

mkdir -p ./bin
ln -s "$PWD/hlf.sh" ./bin/hlf
export PATH="$PWD/bin:$PATH"
hlf install && hlf start && hlf deploy && hlf run

• Terminal 2 (Solana Program)

cd solana-program
npm install
anchor build
anchor test

• Extra: Cleanup & HLF help (Terminal 1)

hlf help
hlf stop

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Setup Instructions

1. Set up hlf CLI (dev-friendly)

The main script for interacing with the project is ./hlf.sh. To use it like a CLI tool(hlf), you can symlink for convenience.

Run the following from the root of the project:

mkdir -p ./bin
ln -s "$PWD/hlf.sh" ./bin/hlf

Then, add the bin directory to your shell’s PATH:

export PATH="$PWD/bin:$PATH"

Note

This export is only valid for your current shell session. If you start a new terminal, you’ll need to re-export or add it to your shell profile (~/.bashrc, ~/.zshrc).

To see all the options run hlf help

2. Start Hyperledger Fabric Network

hlf install
hlf start

Installs Fabric Docker images/binaries, clones fabric-samples repo and start test network.

3. Deploy & Run the Fabric chaincode

hlf deploy
hlf run

Deploys chaincode (as-a-service), installs dependencies, builds, and runs it.

4. Run the Solana program

cd solana-program
npm install
anchor build
anchor test