VeilAuction

Fully confidential sealed-bid auctions on Solana, powered by Arcium MPC.

VeilAuction is a decentralized auction platform where bids remain 100% encrypted from submission through resolution. No one — not validators, not the auction creator, not even the protocol — can see bid amounts until the auction closes and the winner is computed via multi-party computation (MPC).

Features

• Sealed-bid privacy: Bids are encrypted using Arcium's MPC network. Bid values are never visible on-chain.
• First-price auctions: Winner pays exactly their bid amount.
• Vickrey (second-price) auctions: Winner pays the second-highest bid amount, incentivizing truthful bidding.
• SOL-native settlement: Bids are held in on-chain escrow PDAs and released programmatically after resolution.
• Trustless winner determination: The Arcium MPC network computes the winner without ever decrypting individual bids.
• Bid reclamation: Non-winning bidders can reclaim their escrowed SOL after auction resolution.

Architecture

┌─────────────┐     Encrypted Bid     ┌──────────────────┐
│   Bidder    │ ─────────────────────► │  VeilAuction     │
│  (Wallet)   │                        │  Solana Program  │
└─────────────┘                        └────────┬─────────┘
                                                │
                                     Queue Computation
                                                │
                                                ▼
                                       ┌───────────────┐
                                       │  Arcium MPC   │
                                       │  Network      │
                                       │  (3+ Nodes)   │
                                       └───────┬───────┘
                                               │
                                    Callback with Result
                                               │
                                               ▼
                                      ┌──────────────────┐
                                      │  Auction Resolved│
                                      │  (Winner + Price)│
                                      └──────────────────┘

Smart Contracts

Component	Description
programs/veil_auction/src/lib.rs	Anchor program with auction lifecycle: create, bid, close, resolve, claim, reclaim
encrypted-ixs/src/lib.rs	Arcis circuits for encrypted bid tracking and winner determination

Accounts

Account	Purpose
Auction	Stores auction metadata, encrypted state, and bid count
BidEscrow	Holds bidder's SOL in escrow, linked to auction and bidder

Circuits

Circuit	Purpose
init_auction_state	Initializes encrypted auction state (highest bid, highest bidder, second highest, bid count)
place_bid	Encrypted comparison: updates state if new bid is higher
determine_winner_first_price	Reveals winner and payment = highest bid
determine_winner_vickrey	Reveals winner and payment = second-highest bid

Tech Stack

• Solana: Blockchain runtime, account model, program deployment
• Anchor v0.32.1: Solana program framework
• Arcium: MPC network for confidential computation
• Arcis v0.9.6: Rust framework for writing MPC circuits
• Next.js 16: Frontend application
• @solana/wallet-adapter: Wallet integration (Phantom, Solflare)
• @arcium-hq/client: TypeScript client for Arcium MPC

Quick Start

Prerequisites

• Node.js 18+
• Rust 1.82+
• Solana CLI Tools
• Anchor CLI 0.32.1
• Arcium CLI (curl --proto '=https' --tlsv1.2 -sSfL https://install.arcium.com/ | bash)

Install

git clone https://github.com/Glassmahn/VeilAuction.git
cd VeilAuction
yarn install

Build

# Build circuits and Solana program
arcium build

Test

# Run integration tests (requires local validator + Arcium cluster)
arcium test

Deploy to Devnet

# Ensure you have devnet SOL
solana config set --url https://api.devnet.solana.com
solana airdrop 5

# Deploy program and initialize MXE
arcium deploy --cluster-offset 0 --recovery-set-size 3 --keypair-path ~/.config/solana/id.json -u devnet

Run Frontend

npm run dev

Auction Lifecycle

1. Create: Seller creates an auction specifying type (first-price or Vickrey), minimum bid, and duration.
2. Bid: Bidders submit encrypted bids via the Arcium MPC network. Bids are never visible on-chain.
3. Close: After the auction deadline, the seller closes bidding.
4. Resolve: The seller triggers winner determination. Arcium MPC nodes compute the result without decrypting individual bids.
5. Claim: The seller claims the winning payment.
6. Reclaim: Non-winning bidders reclaim their escrowed SOL.

Program ID

Network	Program ID
Devnet	zTkNvsczL8Uvg97KDFKo1PTnPSi8RdAKryyd7d3f2H4

Project Structure

VeilAuction/
├── programs/
│   └── veil_auction/
│       └── src/
│           └── lib.rs          # Anchor program
├── encrypted-ixs/
│   └── src/
│       └── lib.rs              # Arcis MPC circuits
├── build/                       # Compiled circuit artifacts (.arcis, .idarc)
├── app/                         # Next.js frontend
├── tests/
│   └── veil_auction.ts          # Integration tests
├── Anchor.toml                  # Anchor configuration
├── Arcium.toml                  # Arcium cluster configuration
├── Cargo.toml                   # Rust workspace
└── deploy-devnet.sh             # Deployment script

License

MIT