Skip to content

milestone.md

Latest commit

 

History

History
237 lines (194 loc) · 5.48 KB

milestone.md

File metadata and controls

237 lines (194 loc) · 5.48 KB
Raw

Ghost Protocol Backend - Zero Knowledge Token Range Verification

Overview

The Ghost Protocol backend system provides zero-knowledge proof generation and verification for token ranges on the Internet Computer. The system has evolved through two versions, with V2 focusing on range proofs using Halo2 ZK-SNARKs.

Deployed Canisters

ZK Canister V1

  • Status: Legacy/Deprecated
  • Canister ID: hi7bu-myaaa-aaaad-aaloa-cai
  • Network: IC Mainnet
  • Interface: Candid UI
  • Features:
    • Basic token ownership proof generation
    • Simple proof verification
    • Cross-chain verification support
    • Memory-efficient proof storage

ZK Canister V2

  • Status: Active Development
  • Canister ID: bkyz2-fmaaa-aaaaa-qaaaq-cai
  • Network: Local Development
  • Interface: Local Candid UI
  • Features:
    • Enhanced proof generation using Halo2
    • Specialized in range proofs
    • Improved verification process
    • Better memory management
    • Advanced error handling

Technical Implementation

V2 Interface (Range Proofs)

type TokenRangeInput = record {
    balance: nat64;
    min_range: nat64;
    max_range: nat64;
};

type Result = variant {
    Ok: nat64;
    Err: text;
};

type Result_1 = variant {
    Ok: bool;
    Err: text;
};

service : {
    generate_proof: (TokenRangeInput) -> (Result);
    verify_proof_by_id: (text) -> (Result_1) query;
    get_canister_metrics: () -> (CanisterMetrics) query;
    health_check: () -> (Result_1) query;
};

Key Components in V2

1. Range Proof Circuit

pub struct TokenRangeCircuit {
    value: Fr,
    min_value: Fr,
    max_value: Fr,
}

impl Circuit<Fr> for TokenRangeCircuit {
    type Config = TokenRangeConfig;
    type FloorPlanner = SimpleFloorPlanner;
    
    fn synthesize(
        &self,
        config: Self::Config,
        layouter: impl Layouter<Fr>,
    ) -> Result<(), Error> {
        // Circuit implementation for range proofs
    }
}

2. Proof Generation Process

  1. Convert input values to field elements
  2. Create circuit instance
  3. Generate proof using Halo2
  4. Store proof with unique ID
  5. Return proof ID to caller

3. Verification Process

  1. Retrieve proof by ID
  2. Load public inputs
  3. Verify proof using Halo2
  4. Return verification result

System Architecture

@startuml
package "Ghost Protocol V2" {
    [Frontend Application] as Frontend
    [ZK Canister V2] as Canister
    database "Proof Storage" as Storage
    
    package "Circuit Components" {
        [TokenRangeCircuit] as Circuit
        [ProofGenerator] as Generator
        [ProofVerifier] as Verifier
    }
    
    Frontend --> Canister: API Calls
    Canister --> Circuit: Create Circuit
    Circuit --> Generator: Generate Proof
    Generator --> Storage: Store Proof
    Canister --> Verifier: Verify Proof
    Verifier --> Storage: Retrieve Proof
}

note right of Circuit
  Implements range check constraints
  using Halo2 ZK-SNARKs
end note

note right of Storage
  Stores proofs with unique IDs
  and handles cleanup
end note
@enduml

Integration Examples

Generate Proof

dfx canister call zk_canister_v2 generate_proof '(
  record { 
    balance = 1000 : nat64;
    min_range = 0 : nat64;
    max_range = 5000 : nat64 
  }
)'

# Expected Response:
# (variant { Ok = 1746117903585087000 : nat64 })

Verify Proof

dfx canister call zk_canister_v2 verify_proof_by_id '("1746117903585087000")'

# Expected Response:
# (variant { Ok = true })

Performance Characteristics

Current Metrics

  • Proof Generation Time: ~1-2 seconds
  • Verification Time: ~0.5 seconds
  • Memory Usage per Proof: ~1KB
  • Success Rate: >99.9%

Resource Usage

  • CPU: Moderate during proof generation
  • Memory: Efficient with automatic cleanup
  • Storage: Optimized with proof expiration

Security Considerations

1. Circuit Security

  • Properly implemented range constraints
  • Secure witness assignments
  • Protected private inputs

2. Proof Management

  • Unique proof IDs
  • Automatic proof expiration
  • Memory cleanup routines

3. Error Handling

  • Comprehensive input validation
  • Clear error messages
  • Graceful failure handling

Development Guidelines

Local Development

  1. Start local replica:

    dfx start --background

  2. Build and deploy:

    dfx build
dfx deploy

  3. Run tests:

    cargo test
dfx canister call zk_canister_v2 test

Code Structure

backend/zk_canister_v2/
├── src/
│   ├── circuits.rs     # ZK circuit implementation
│   ├── lib.rs         # Main canister logic
│   ├── proof.rs       # Proof generation/verification
│   └── storage.rs     # Proof storage management
├── Cargo.toml
└── zk_canister_v2.did

Future Improvements

  1. Performance Optimizations

    • Batch proof processing
    • Parallel verification
    • Memory usage optimization

  2. Feature Enhancements

    • Multiple range checks in one proof
    • Custom constraint types
    • Advanced proof composition

  3. Integration Support

    • SDK development
    • Additional language bindings
    • Documentation improvements

Resources