Security & Audits

Trust model, security architecture, and audit history

Trust Model

Relay Settlement is designed to be non-custodial — no single entity can unilaterally access user funds. Each component has different trust properties:

Depository

The Depository contracts are the most trust-minimized component:

• Non-upgradable — Contract logic is immutable after deployment
• Single authorization path — Only the registered Allocator can authorize withdrawals
• Short custody duration — Funds are typically held for seconds to minutes, not hours or days
• No admin withdrawal — There is no backdoor function for the contract owner to withdraw user funds

The Depository’s security relies on the Allocator’s signing authority. If the Allocator is compromised, it could authorize unauthorized withdrawals — but it cannot create balances that don’t exist on the Hub.

Oracle

The Oracle determines which deposits and fills are considered valid:

• Can attribute balances — The Oracle controls what gets minted, transferred, or burned on the Hub
• Cannot steal Depository funds — Even an incorrect attestation only affects Hub balances. The Allocator independently verifies Hub balances before authorizing any withdrawal.
• Consensus threshold — Attestations require signatures from a threshold of independent validators. The onchain Oracle contract verifies the threshold is met before executing any action on the Hub.

The Oracle is the main trust-bearing component. A compromised minority of validators cannot submit false attestations. A compromised majority could incorrectly attribute balances, but the damage is bounded by the Allocator’s balance checks and the Security Council’s ability to pause the system.

Hub

The Hub is a deterministic smart contract on the Relay Chain:

• Rule-based — Balance changes only occur through Oracle-attested actions (MINT, TRANSFER, BURN)
• Idempotent — The same attestation cannot be processed twice
• Transparent — All balance changes are visible on the Relay Chain block explorer

Allocator

The Allocator controls withdrawal authorization:

• MPC signatures — No single entity holds the full signing key
• Balance-bounded — Can only authorize withdrawals up to a solver’s Hub balance
• Governed by Security Council — A multisig can pause or replace the Allocator
• Replay-protected — Nonces and expirations prevent proof reuse

Security Council

The Security Council is a multisig that governs the Allocator. Any single member can immediately pause all withdrawals, while structural changes (replacing the Allocator, changing membership) require a supermajority. Because all withdrawals flow through a single Allocator, the entire protocol across 80+ chains can be paused with a single transaction.

See the full Security Council page for details on tiered thresholds and scope.

Audits

The protocol has been audited by leading security firms:

Date	Scope	Auditor	Report
February 2025	Relay Depository (EVM)	Spearbit	View Report
June 2025	Relay Depository (EVM)	Certora	View Report
November 2025	Settlement Protocol	Zellic	View Report

Bug Bounty

Details of the Relay bug bounty program can be found on the Relay GitHub.

Source Code

All protocol contracts are open source:

• settlement-protocol — Hub, Oracle, Allocator contracts
• relay-depository — Depository contracts (EVM + Solana)