FHE Encrypted Limit Orders on Uniswap v4

iceberg-cofhe introduces confidential, iceberg-style limit orders to Uniswap v4 using Fully Homomorphic Encryption (FHE) via the Fhenix coprocessor. Limit order data like trade size and direction are encrypted on-chain and privately stored in the Iceberg hook
— enabling privacy-preserving DeFi trading.

🔒 Built with FHE
🦄 Runs as a Uniswap v4 hook
🚀 Enables private, on-chain limit orders

• Users place encrypted limit orders through the hook (placeIcebergOrder) by providing encrypted values:
  • liquidity: order size
  • zeroForOne: swap direction
• The ticklower price is public, just like a traditional iceberg order. It shows the price you wish to execute a swap without exposing trade size or direction. e.g. the order could be 1 or 1,000,000 and it could be buying or selling token0/token1.
• Orders are stored in a privacy-preserving mapping, protected by FHE.
• In the afterSwap() callback the hook evaluates encrypted order conditions without leaking user intent.
• Once matching conditions are met, decryption is securely requested to fill the order.
• In the next beforeSwap() callback, the decryption result is requested.
  • If the decryption is ready, the order is filled.
  • Otherwise, the swap lifecycle continues

Requires foundry.

#manage foundry toolchain
foundryup

#install dependencies using npm/pnpm
pnpm install

#flag is required, or else stack too deep errors!
forge test --via-ir

#verbose logging and stack traces
forge test --via-ir -vvvv

Other than writing unit tests (recommended!), you can only deploy & test hooks on anvil

# start anvil, a local EVM chain
anvil

# in a new terminal
forge script script/Anvil.s.sol \
    --rpc-url http://localhost:8545 \
    --private-key 0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80 \
    --broadcast

See script/ for hook deployment, pool creation, liquidity provision, and swapping.

Fhenix 🔒

• FHE Hook Template
• CoFhe docs
• FHERC20 Token Docs

Uniswap 🦄

• Awesome Uniswap Hooks
• Hook Examples
• Uniswap v4 docs
• v4-periphery
• v4-core
• v4-by-example

Other 🧊

• Traditional Iceberg Orders