Arcium Examples

Example applications built with Arcium, the encrypted compute network on Solana. Each example computes on encrypted data using multi-party computation (MPC): confidential inputs stay encrypted end to end, and no compute node sees them in plaintext.

How Arcium works

The examples share the same computation lifecycle:

1. The client submits plaintext or locally encrypted inputs. Confidential client inputs use x25519 key exchange and RescueCipher.
2. The Anchor program queues a computation with the Arcium program.
3. An MPC cluster executes the encrypted instruction defined in encrypted-ixs/.
4. The result returns on-chain via a callback instruction, which stores or reveals it.

Data stays private as long as one node in the cluster is honest; the protocol tolerates a dishonest majority. See Core Concepts and Computation Lifecycle for the full picture.

Examples

Recommended path: work through them in order. Each introduces one new pattern.

Example	Pattern	Encrypted on-chain state	Main concept
Coinflip	Trustless randomness	No	ArcisRNG, revealing results
Rock Paper Scissors	Hidden moves	Yes (vs player), No (vs house)	Enc<Shared, T> inputs, RNG opponent
Voting	Private aggregation	Yes	Enc<Mxe, T> accumulators, callbacks
Medical Records	Controlled sharing	Yes	Re-encryption to a new owner
Sealed-Bid Auction	Encrypted comparison	Yes	First-price and Vickrey clearing prices
Blackjack	Hidden game state	Yes	Pack<T> storage efficiency
Ed25519 Signatures	Distributed signing	No	Keys that never exist in one place

Running an example

Prerequisites: the Arcium CLI, which requires Rust, the Solana CLI, Anchor, and Docker. Toolchain versions are pinned per example in Cargo.toml and rust-toolchain.toml.

Every example builds and tests the same way:

cd voting        # or any example
yarn install
arcium build     # compiles the encrypted circuit and the Anchor program
arcium test      # runs the tests against a local Arcium cluster

Each example has the same layout:

encrypted-ixs/   # Arcis circuit: the code that runs inside MPC
programs/        # Anchor program: queues computations, handles callbacks
tests/           # TypeScript tests: encryption happens client-side here

Troubleshooting

• arcium test hangs at keygen after a version bump: stale localnet cache. Remove artifacts/localnet/mxe_utility_pubkeys.bin and artifacts/localnet/private_shares_node_*, then rerun.
• Computation stuck in queued: the local cluster did not finalize; rerun the test. Persistent failures usually mean the circuit and program are out of sync: run arcium build again.
• AbortedComputation in a callback: the MPC output failed verification. Check that the argument order in the queue call matches the circuit signature exactly.

Documentation

Mental Model · Arcis reference · Best Practices · Discord

These examples are for learning. They are not audited and cut corners a production deployment must not; see each example's Limitations section.