UTXO programmability for Bitcoin Bitcoin Cash Liquid Arkade Fractal
Sighash Labs helps teams design, build, and secure applications on Bitcoin, Bitcoin Cash, OPCAT layer, and Bitcoin-like UTXO systems. We provide consulting, development, and audits for smart contracts, covenant protocols, transaction flows, and L2 infrastructure.
What we do
Consulting, development, and audits for UTXO teams
UTXO applications are won or lost in the details: script limits, transaction topology, state encoding, wallet behavior, mempool policy, and adversarial signing paths. We help teams reason through those constraints and ship working systems.
UTXO Smart Contract Development
Design and implementation support for covenant-driven applications, transaction builders, wallet flows, and production UTXO contracts.
Protocol Design & Consulting
Hands-on guidance for teams building on Bitcoin, Bitcoin Cash, OPCAT layer, Liquid, Arkade, Fractal, and related Bitcoin-like systems.
Security Audits
Manual reviews of UTXO smart contracts, transaction protocols, bridge assumptions, and application logic before launch.
How we work
From transaction design to launch review
Engagements can be advisory, implementation-heavy, audit-focused, or a mix. The common thread is precise reasoning about the UTXO model and the product constraints around it.
Map the transaction model
We start from the exact scripts, covenants, state transitions, signing flows, and chain constraints your product depends on.
Design or review the protocol
We pressure-test the off-chain and on-chain pieces together, including failure modes, fee handling, replay risks, and upgrade paths.
Build with your team
Engagements can include implementation, test harnesses, transaction construction, wallet integration, or focused engineering review.
Harden before release
For audit work, you get concrete findings, exploit paths where relevant, and follow-up review of fixes.
When to contact us
Bring us in before the transaction model hardens
The best time to catch UTXO protocol issues is while the architecture is still flexible. We can help at the design, build, or pre-launch review stage.
Discuss a UTXO projectYou are designing a UTXO smart contract protocol and need the transaction model reviewed.
You need help turning a protocol spec into working scripts, transactions, tests, or wallet flows.
You are preparing for launch and want an independent review before funds are at risk.
You are unsure whether your covenant, state, or signing model is safe under adversarial conditions.
Why sighash
Specialized in Bitcoin-style programmability
General smart contract experience does not automatically translate to UTXO systems. Sighash Labs focuses on the transaction-level design, contract constraints, and protocol edge cases that matter on Bitcoin, Bitcoin Cash, and adjacent chains.
- Deep experience with UTXO smart contracting and Bitcoin-style transaction semantics.
- Practical support across consulting, implementation, and independent security review.
- Clear scopes and direct collaboration with the engineer doing the work.
Separate audit archive
Audits library
Published audit reports remain available on a dedicated page, separate from consulting and development services.