Trail of Bits

Trail of Bits is a New York-based security firm founded in 2012 whose blockchain practice covers smart contracts, nodes, bridges and cryptography alongside non-blockchain work such as AI/ML and supply-chain security. It fits teams that want a private, multi-week review of protocol- or client-level code and expect fuzzing harnesses and invariant tests as deliverables, not only a findings list. The strongest public signal is volume and recency of published work: its report catalog listed 656 public reports, 474 of them in the blockchain domain, when re-checked on 2026-10-14 (620 and 454 on 2026-09-24).

At a glance

Founded	2012 (about page)
Headquarters / jurisdiction	New York, NY; mailing address 228 Park Ave S, New York (contact page)
Engagement model	Private firm audit and consulting
Core specialties	Smart contract and node/client review, cryptography, invariant testing and fuzzing, design review (blockchain services)
Ecosystems / languages	EVM (Solidity), Arbitrum/Optimism, Solana (Rust), Cosmos, Substrate, Starknet (Cairo), TON (FunC), Move (Aptos/Sui) per the firm's services page; published reports confirm EVM, Arbitrum, Solana, cryptography and ZK circuits
Public report index	trailofbits.com/reports and github.com/trailofbits/publications
Open-source tooling	Slither, Echidna, Medusa (via the crytic GitHub org); Building Secure Contracts guidance
Published pricing	Not published

What they do

The firm's blockchain services page lists four engagement types: design assessment (architecture, deployment plans, oracle risk), early-stage assessment, invariant testing and development (custom fuzzing wired into CI), and comprehensive code assessment covering smart contracts, nodes, bridges and infrastructure. It describes a five-stage process: scope and threat model, design and upgradeability review, implementation review with automated tools, invariant testing and exploit development, then reporting with live walkthroughs and patch retesting. The same page says engagements ship custom detectors, invariant test suites, codebase maturity evaluations and CI-ready fuzzing harnesses.

Outside blockchain, the about page lists software assurance, AI/ML security, application security, cryptography consulting, security engineering and R&D. The firm publishes reports that clients clear for release, per its reports page; publication is therefore client-controlled rather than guaranteed.

Specialties and ecosystem coverage

• EVM / Solidity: Well evidenced. Recent catalog entries include Aave v4 (2026-02), Gensyn vault and bridged-token reviews (2026-04) and Kiln Lagoon Vault (2026-05) (reports).
• Arbitrum / L2 clients: Well evidenced through a run of Offchain Labs reviews (ArbOS, Stylus, Nitro) listed in the publications repo.
• Cryptography and ZK: Evidenced by 2026 reviews of Ripple's XRP Ledger confidential transfers, Anza BLS signatures and NEAR One robust ECDSA (reports), a Polygon Labs Iden3 circuits review and an Axiom Halo2 libraries review (publications README), and the firm's 2022 "Frozen Heart" disclosure (blog).
• Solana: Evidenced (e.g. Reserve Solana DTFs, April 2025, in the publications repo).
• Cosmos, Algorand, Starknet, TON: The publications README has section headers for these ecosystems.
• Directory chains: Ethereum, Arbitrum, Solana, Cosmos and Polygon are confirmed by published work. Optimism appears on the services page, but no Optimism-specific report was confirmed in this pass.
• Bridges: The services page claims bridge coverage. No bridge-specific report was confirmed in this pass.

Recent public work

Taken from the reports catalog and the publications repo on 2026-09-24:

Re-checked 2026-10-14, the catalog had added September 2026 reports for OpenAI (OpenClaw), Yon Labs, Google (Private AI Compute), Amazon (Bee) and Offchain Labs (OSP).

1. Offchain Labs Arbitrum ArbOS 60/61 (July 2026) (publications)
2. Kiln Lagoon Vault diff review (May 2026) (reports)
3. Offchain Labs Stylus SDK (April 2026) (publications)
4. Franklin Templeton BenjiSwap differential review (April 2026) (reports)
5. Gensyn Buyback-and-Burn Vault, Bridged Token and Delphi markets (April 2026) (reports)
6. Ripple Labs XRP Ledger Confidential Transfer (April 2026) (reports)
7. Anza BLS Signatures (March 2026) (reports)
8. Aave v4 (February 2026) (reports)
9. Offchain Labs Arbitrum Nitro External DA (January 2026) (publications)
10. Uniswap v4 Core (July 2024) (publications)

Research, tooling and methodology

• Tools: The crytic org, described there as Trail of Bits' blockchain security arm, maintains Slither (static analysis for Solidity and Vyper), Echidna (a property-based fuzzer) and Medusa (a parallel fuzzer built on go-ethereum). The about page dates the release of Slither and Echidna to 2018.
• Guidance: Building Secure Contracts covers development guidelines, code-maturity criteria, token-integration checklists, "Not So Smart Contracts" vulnerability examples and tool tutorials, for EVM, Algorand, Cairo, Cosmos, Substrate, Solana, Sui and TON.
• Recent research: The blockchain blog category includes posts on Uniswap v4 hook security (July 2026), mistakes in ERC-4337 smart accounts (March 2026), dimensional analysis for DeFi bugs (March 2026), Slither-MCP for LLM tooling (November 2025) and an analysis of the Balancer hack (November 2025).
• Disclosures: "Frozen Heart" (April 2022) was a coordinated disclosure of Fiat-Shamir implementation flaws that affected libraries including SnarkJS, gnark and Dusk Network's PLONK (blog).
• Report data: The publications repo also contains a dataset of smart contract audit findings.

Track record and incidents

• Raft (November 2023): Raft's R stablecoin was exploited on 10 November 2023 through a precision issue in share-token minting (CoinDesk). rekt.news names Trail of Bits and Hats Finance among Raft's auditors. Crypto Daily, citing Raft, reported that the exploited contracts had been audited by Trail of Bits and Hats Finance and that the vulnerability was not detected in those audits. This pass could not load Raft's original post-mortem, so the exact audited commit versus deployed code could not be compared. No public response from Trail of Bits was found. An exploit after an audit does not by itself show that a finding was missed.

Who should consider them — and who might look elsewhere

The public evidence is strongest for L2 client and node code (Arbitrum), EVM DeFi, and cryptography or ZK primitives. It also fits teams that want fuzzing and invariant suites handed over for ongoing CI use. Teams on Move, Cairo or TON may want to ask for recent public examples first, because this pass saw these ecosystems in the services page and guidance repo but did not verify recent published reports for them. Projects that need a published fixed price, or a competitive-contest format, will not find either on the firm's own pages.

How to engage

Use the contact form on the contact page, which also offers SendSafely or PGP for sensitive material. The blockchain services page mentions quote requests and free technical office hours with engineers. Before scoping, prepare a frozen commit, architecture and threat-model notes, deployment and upgrade plans, and any existing invariants or tests, since the firm's process begins with scope and threat modelling.

Gaps and unverified claims

• Team size is not published on the pages fetched, so the directory's "200+" is unverified.
• Pricing and turnaround are not published. Engagement lengths in the publications repo range from about 2 weeks to 47 weeks, so the directory's "6-12 weeks" is not a firm-published figure.
• Of the directory's notable audits, Uniswap and Compound (a compound-2.pdf report file) were confirmed. MakerDAO, Lido and Yearn reports were not located in this pass. Algorand appears only as a README section header.
• No Optimism-specific or bridge-specific public report was confirmed in this pass.
• The reports page shows "25 Clients / groups" next to the report total (656 on 2026-10-14). That figure looks like a grouping count and should not be read as a total client count.
• Raft's own post-mortem could not be loaded (the Paragraph URL returned 404), so the scope details above rely on press reporting.

Sources

1. Trail of Bits — About, accessed 2026-09-24
2. Trail of Bits — Reports catalog, accessed 2026-09-24
3. trailofbits/publications (GitHub), accessed 2026-09-24
4. trailofbits/publications README, accessed 2026-09-24
5. trailofbits/publications — compound-2.pdf, accessed 2026-09-24
6. Trail of Bits — Blockchain services, accessed 2026-09-24
7. Trail of Bits — Contact, accessed 2026-09-24
8. crytic GitHub org, accessed 2026-09-24
9. crytic/building-secure-contracts, accessed 2026-09-24
10. Trail of Bits blog — blockchain category, accessed 2026-09-24
11. Trail of Bits blog — Frozen Heart disclosure, accessed 2026-09-24
12. rekt.news — Raft REKT, accessed 2026-09-24
13. Crypto Daily — Raft audits report, accessed 2026-09-24
14. CoinDesk — Raft exploit, accessed 2026-09-24