Overview
SHROUD is a SOL perpetuals venue on Solana where a position's side, size, leverage and liquidation price are encrypted before they leave the trader's browser. Arcium's multi-party computation (MPC) cluster checks those encrypted positions against the oracle price and reveals only which ones to liquidate. When a position closes, the only number revealed is its payout.
Why it exists
On-chain perp venues store every position as public state. Anyone can read a large position's liquidation price and push the market toward it. SHROUD keeps that number sealed for the life of the position.
What is public and what is not
| Anyone can see | Nobody can see |
|---|---|
| Collateral deposited and paid out (plain USDC transfers) | Long or short |
| That a wallet opened a position, and when (so the entry price) | Size, and so leverage |
| Which book slot the position occupies | The liquidation price |
| That a slot was liquidated, after it happens | Open profit or loss |
| The payout at close |
The parts
- Your browser works out the liquidation threshold and encrypts size, side and threshold with Arcium's Rescue cipher (an x25519 key exchange, then Rescue in counter mode).
- The Solana program holds the USDC vault, the LP pool, the sealed book and every position account.
- Arcium's cluster runs three circuits on secret shares:
open_pos,chk128andclose_pnl. - Keepers (anyone) queue check rounds at the oracle price and settle marked slots for a 1% reward.
- LPs fund the one pool that takes the other side of every trade.
Where it runs today
The engine is tested end to end on a local Arcium cluster with two nodes: 24 positions opened with USDC collateral, a check round at a lower price marked exactly the liquidatable slots, and every close paid out to the micro-USDC of the plain-text formula. The numbers are on the Measurements page.