ZK-Port Inter-Chain Hub

ZK-Port is a unified, privacy-preserving asset management and cross-chain transfer hub designed to connect multiple blockchain ecosystems, including Ethereum, Solana, Cosmos, Avalanche, Polygon and Polkadot (and more). This project leverages the power of Rust, zero-knowledge proofs (ZKPs), and cross-chain interoperability standards (like IBC and XCMP) to create a scalable and trust-minimized multichain platform.

Vision

ZK-Port aims to solve the fragmented multichain experience by:

• Aggregating fungible token balances from multiple chains in one seamless interface.
• Enabling private and secure cross-chain transfers with ZKPs, ensuring user balances or eligibility are proven without being fully revealed.
• Supporting multiple blockchain paradigms, including EVM-compatible chains, Substrate-based chains, and Solana.
• Showcasing the potential of Rust as the core programming language for multichain applications.

Key Features

🔵 Unified Asset Dashboard

• Aggregate and display fungible token balances across Ethereum, Solana, Cosmos, Avalanche, Polygon, and Polkadot.
• Provide real-time updates and portfolio valuation.
• Support wallet integrations for each chain (e.g., Metamask for EVM chains, Phantom for Solana, Keplr for Cosmos, and Polkadot.js for Polkadot).

🔵 ZK-Enabled Privacy

• Prove ownership of tokens across chains without revealing exact balances using ZKPs.
• Generate proofs for eligibility or threshold balances (e.g., “User owns at least 100 SOL”).

🔵 Cross-Chain Transfers

• Enable fungible token transfers between chains using:
  • Bridges for EVM and Solana.
  • IBC for Cosmos.
  • XCMP/XCM for Polkadot.
• Handle bridging complexity seamlessly through backend services.

🔵 Built for Developers

• Entire stack built in Rust, showcasing a professional-grade, modular, and scalable architecture.
• Designed to be extensible: adding new chains or proof types involves minimal effort.

Architecture

Overview Diagram

[Wallets/Front-End]
       |
[Backend (Rust)]
       |
       +--> Solana (Rust)
       |
       +--> Ethereum/Avalanche/Polygon (EVM)
       |
       +--> Cosmos (IBC)
       |
       +--> Polkadot (XCMP)

Backend (Rust)

The backend is implemented entirely in Rust, designed to handle data aggregation, cryptographic computations, and cross-chain communication efficiently and securely.

Responsibilities

• Fetching token balances from multiple blockchain ecosystems.
• Aggregating and storing cross-chain token data in a secure database.
• Generating zero-knowledge proofs to validate user requests without revealing sensitive data.
• Managing communication and transactions for cross-chain interoperability, including bridging and message relaying.

Core Technologies

• API Frameworks: Axum for building REST APIs, providing high performance and async support.
• Database: PostgreSQL or SQLite for storing user sessions, token balances, and cached blockchain states.
• Cryptographic Libraries: Arkworks and Halo2 for designing and verifying zero-knowledge proof circuits.
• Blockchain Interaction Crates:
  • solana-client: For querying Solana RPC nodes and submitting transactions.
  • ethers-rs: For interacting with EVM-compatible chains like Ethereum, Avalanche, and Polygon.
  • cosmrs: For querying Cosmos chains and creating IBC messages.
  • substrate-api-client: For interacting with Polkadot and its parachains.
• Bridging Protocols: Wormhole, LayerZero, and Axelar for cross-chain transfers and messaging.
• Logging: tracing for structured logging and Prometheus-compatible libraries for metrics collection.
• Asynchronous Runtime: Tokio for handling concurrency across blockchain networks.

Zero-Knowledge Proofs

Zero-knowledge proofs are foundational to the privacy-preserving features of ZK-Port.

Key Concepts

• Privacy-First Validation: Ensuring that sensitive information, such as exact token balances, is not exposed during proof generation.
• Circuit Design: Leveraging Rust-based libraries to construct modular, efficient ZK circuits capable of threshold and aggregation proofs.
• Efficiency Focus: Optimized circuit design minimizes computation and on-chain verification costs while maintaining scalability.

ZK Flow

1. Request Initialization: A user submits a transfer or validation request.
2. Data Fetching: The backend securely queries balances or state information from the relevant blockchains.
3. Proof Generation: A ZK proof is generated using cryptographic libraries, validating the requested condition (e.g., balance threshold).
4. Verification: The proof is either verified on-chain or relayed to the target chain for further action.

Cross-Chain Integrations

Ethereum/Avalanche/Polygon (EVM-Compatible)

Ethereum, Polygon and Avalanche are integrated as EVM-compatible chains, leveraging existing token standards and bridging solutions. Token balances are aggregated using secure RPC endpoints.

Solana

Solana’s high-throughput ecosystem is connected via custom Rust-based programs, enabling efficient bridging and state validation.

Cosmos

Cosmos inter-chain communication is facilitated using IBC protocols, relaying token information and enabling secure transfers between chains.

Polkadot

Polkadot’s Substrate-based chains are integrated through XCMP/XCM, with future support planned for trust-minimized light client verification.

Roadmap

Backend (Rust)

• Implement wallet connection logic for
  • Solana
  • Ethereum
  • Avalanche
  • Polygon
  • Cosmos
  • Polkadot
• Aggregate token balances across chains.
• Design and optimize ZK circuits for threshold proofs.
• Integrate bridging solutions for EVM and Solana.
• Add IBC message relaying for Cosmos.
• Simulate or implement XCMP calls for Polkadot.

On-Chain Programs

• Solana program for ZK proof verification.
• Minimal on-chain contract for IBC message verification.
• Polkadot XCMP module for token transfers.

Frontend

• Integrate wallet connections for supported chains.
• Display token balances and portfolio valuation.
• Implement cross-chain transfer UI.
• Visualize ZK proof generation and verification.