Shadow-swap

1. Shadow-swap: Privacy-Preserving Intent-Based Cross-Chain Bridge

The Problem

Current cross-chain bridges expose every transaction detail publicly—sender addresses, amounts, recipients, and timing patterns. Users must wait 10-30 minutes for confirmations while their financial activity is tracked. Meanwhile, massive liquidity sits idle in bridge pools earning minimal returns, and users pay high fees for slow, privacy-invasive service.

Our Solution

Shadow-swap reimagines cross-chain bridging by combining cryptographic privacy with intent-based architecture. Users express bridging intent using zero-knowledge-friendly commitments that hide their identity. A competitive network of solvers races to provide instant liquidity on the destination chain within seconds. The entire process maintains complete privacy—no one can link deposits to withdrawals or trace user activity across chains.

How It Works

When a user wants to bridge assets, they generate a secret and nullifier, then compute a cryptographic commitment using Poseidon hashing. They submit this commitment to the source chain's IntentPool contract along with their tokens. The commitment reveals nothing about the user's identity or the transaction details.

Our relayer system detects the intent, generates merkle proofs, and registers it on the destination chain's Settlement contract. Solvers monitoring these registrations evaluate profitability based on fees, gas costs, and risk scores. The first solver to fill the intent provides immediate liquidity to the user on the destination chain.

Meanwhile, the relayer securely retrieves the user's secret and executes a privacy-preserving claim that transfers the destination tokens to the user's chosen recipient address. This recipient can be completely different from the original depositor, breaking any on-chain link between the two transactions.

Finally, solvers prove they filled the intent by submitting merkle proofs to the source chain's IntentPool, where they get reimbursed from the original user deposit. The entire cycle completes in approximately 60 seconds with full privacy preservation.

Key Features

Privacy Guarantees: Zero-knowledge-friendly Poseidon commitments hide user identities. Nullifiers prevent double-spending without revealing transaction history. Flexible recipient addresses enable complete unlinkability between deposits and withdrawals. No on-chain data reveals who bridged what or when.

Instant Liquidity: Competitive solver network provides destination liquidity within seconds instead of waiting for lengthy bridge confirmations. Users get their funds immediately while solvers handle the cross-chain settlement asynchronously.

Capital Efficiency: Solvers earn 0.15% fees on deployed capital. Users pay only 0.15% total fees versus 0.5-2% on traditional bridges. No massive idle liquidity pools required—capital actively deployed by profit-motivated market makers.

Multi-Token Support: Native support for ETH, WETH, USDC, USDT, and MNT with per-token configuration for minimum and maximum amounts. Each token has chain-specific addresses and decimal handling built into the system.

Production-Grade Infrastructure: Built with Rust and Solidity using industry-standard patterns. Comprehensive error handling, automated health monitoring, metrics tracking, and graceful degradation. PostgreSQL for persistent state, WebSocket providers for real-time event monitoring, structured logging throughout.

Technical Architecture

Smart Contracts: Each chain deploys two contracts. PrivateIntentPool manages user deposits, stores commitment merkle trees, and reimburses solvers. PrivateSettlement registers intents from the relayer, allows solvers to fill them, and executes privacy-preserving withdrawals. All merkle operations use canonical hashing for cross-chain proof compatibility.

Relayer System: Monitors both chains for IntentCreated events. Generates merkle proofs from off-chain commitment trees. Registers intents on destination Settlement contracts. Synchronizes merkle roots bidirectionally every 60 seconds. Manages user secrets securely with just-in-time retrieval and immediate purging after use. Coordinates the entire bridging lifecycle from intent creation to solver reimbursement.

Solver Network: Evaluates every registered intent for profitability using configurable parameters—minimum profit threshold in basis points, risk scoring based on intent age and amount, capital reserve requirements per token. Automatically approves ERC20 tokens and manages balance across chains. Submits fill transactions to Settlement contracts and later claims reimbursement from source IntentPools with merkle proofs.

Security Model

Solvers stake their own capital to provide instant liquidity, creating economic incentives for honest behavior. ReentrancyGuard and Checks-Effects-Interactions patterns prevent common exploit vectors. Deadline validation ensures intents can't be filled after expiry. Balance checks before transfers prevent failed claim attempts. Intent parameter validation ensures commitment integrity throughout the lifecycle.

Privacy is cryptographically guaranteed—commitments computed as Poseidon hashes of secret, nullifier, amount, and chain parameters reveal nothing about the underlying data. User secrets are ECIES encrypted and can only be decrypted by the relayer at the point of claiming, ensuring secrets remain protected even if the database is compromised. Nullifiers marked on-chain after claims prevent double-spending while maintaining unlinkability. Flexible withdrawal addresses break any connection between depositor and recipient.

Current Status & Metrics

Deployed on Ethereum Sepolia and Mantle Sepolia testnets. Successfully processed 50+ test bridges. Average fill time under 60 seconds from intent creation to destination liquidity. Gas costs optimized to approximately 120K for fills and 90K for claims.

Roadmap

Immediate focus on mainnet deployment with security audit from reputable firm. Gradual volume ramp starting at $10K daily limits, scaling to $1M+ based on system performance and solver participation. Building decentralized relayer network to eliminate single point of failure. Expanding solver dashboard with real-time profitability analytics and automated capital rebalancing recommendations.

Next phase includes multi-chain expansion to Arbitrum, Starknet, Optimism, and Base. Implementing MEV-resistant solver selection mechanisms to ensure fair competition. Researching zk-SNARK integration for amount hiding to achieve complete transaction privacy.

Long-term vision extends beyond simple asset transfers—enabling privacy-preserving cross-chain DeFi interactions, anonymous DAO voting across chains, and confidential multi-chain treasury management. Shadow-swap serves as infrastructure for a truly private, interoperable blockchain ecosystem where users control their financial privacy without sacrificing efficiency or user experience.

2. Veil Wallet: Privacy-First DeFi Without Compromise

Veil is a non-custodial smart account wallet that brings true financial privacy to Mantle and EVM chains. Unlike traditional wallets that expose your entire transaction history and balances on-chain, Veil offers dual-mode operation: use public addresses for normal transactions or switch to private mode for confidential transfers that hide amounts and recipients.

Built on Account Abstraction (AA) infrastructure, Veil leverages smart accounts to enable powerful features like transaction batching—execute multiple operations in a single transaction to save on gas costs and improve efficiency. Privacy-preserving cryptography is built into the core architecture, supporting all ERC20 tokens while giving you control over what financial information you share.

Transfer tokens privately between Veil users, batch multiple DeFi interactions into one transaction, interact with protocols anonymously, or seamlessly switch back to public mode when transparency is needed—all within a single interface powered by smart contract accounts.

No more choosing between privacy and functionality. Veil gives you both, putting you back in control of your financial privacy while maintaining full compatibility with the EVM ecosystem.

Key Features:

• Smart account architecture with Account Abstraction (AA)

• Transaction batching for gas efficiency

• Dual public/private mode operation

• Full ERC20 token support

• Privacy-preserving transfers with hidden amounts

• Non-custodial—you control your keys

• Seamless integration with existing EVM infrastructure