What is Offshore Cash?

Offshore Cash is a non-custodial privacy protocol for cryptocurrency transfers. It uses zero-knowledge proofs to break the on-chain link between deposit and withdrawal addresses.

The Problem

Every transaction on Ethereum and other blockchains is publicly visible. Anyone can trace the flow of funds between addresses, compromising financial privacy.

The Solution

Offshore Cash uses a single shared pool where users deposit funds. When withdrawing, a zero-knowledge proof demonstrates that the withdrawal is authorized — without revealing which deposit it corresponds to.

Deposit (Public)          Pool (Private)           Withdraw (Public)
┌──────────┐            ┌──────────────┐          ┌──────────────┐
│ Address A │ ────ETH──→ │              │ ──ETH──→ │  Address X   │
│ Address B │ ────ETH──→ │  MainPool    │ ──ETH──→ │  Address Y   │
│ Address C │ ────ETH──→ │  (ZK Proof)  │ ──ETH──→ │  Address Z   │
└──────────┘            └──────────────┘          └──────────────┘
                     No link between A↔X, B↔Y, C↔Z

Key Features

• Arbitrary amounts — deposit and withdraw any amount (not fixed denominations)
• Partial withdrawals — withdraw part of your deposit, keep the rest in the pool
• Relayer network — withdrawals go through relayers so your wallet never touches the withdrawal transaction
• Ethereum native — built on Ethereum Mainnet
• Non-custodial — only your secret note can authorize a withdrawal