Certora helps 1inch bring you secure cross-chain swaps

The collaboration between 1inch and Certora shows how protocol design, incentives and timing can be strengthened through independent review.

DeFi security involves more than catching bugs or plugging vulnerabilities. Preventing those types of risks is important, but there’s another layer that matters just as much: testing how the protocol itself behaves under real-world conditions.

Users come to 1inch for cross-chain swaps because they’re confident that our system works reliably when it matters most.

When they order a cross-chain swap, they expect a simple outcome: assets move from one chain to another, correctly and on time. Behind the scenes, that process depends on precise infrastructure design.

If the system isn’t carefully built, major issues can arise, such as:

• Funds getting delayed or stuck
• Execution windows failing under timing pressure
• Incentives breaking under stress

Protocol security is what ensures these problems are prevented. That’s where Certora comes in. Certora’s Prover has secured over $100 bln in TVL across protocols like Aave, Uniswap, Lido, and EigenLayer – making them one of the most experienced security firms in DeFi.

What protocol security actually means

In practice, protocol security ensures that funds can’t be accessed by the wrong party, that timing windows behave as expected, that incentives remain aligned between participants, and that edge cases don’t break execution.

Most of this work is invisible and behind the scenes. If every transaction works smoothly, that’s a sign that the system is secure.

1inch’s cross-chain swap mechanism is built on atomic execution - no bridges, no wrapped tokens, no third-party validators. It uses a commit–reveal design, in which a secret is cryptographically committed, funds are locked based on that commitment, and then the correct secret is revealed to complete the swap.

This approach sidesteps the heavy infrastructure, like validators or complex oracle systems, that has made cross-chain bridges the single largest source of DeFi exploits. Instead, it relies on cryptography and aligned incentives. That’s an elegant and efficient solution, but even elegant designs require careful scrutiny.

Cross-chain systems introduce complexity around multiple blockchains, multiple participants, strict timing dependencies, and intricate economic incentives. Small misalignments across any of these variables may create friction or risk. That’s why independent review is critical.

How Certora reviewed our cross-chain architecture

Certora concentrated on mission-critical swap features - starting with timing windows. The maker controls when the secret is revealed, but the taker still needs enough time to complete the swap. Secure and accurate timing windows bring users more reliable execution and reduce the risk of stuck funds.

Every swap also depends on a safety deposit that reinforces honest behavior. Certora identified potential risks that might arise from deposit infrastructure.  Based on their findings, the safety deposit logic was tightened to ensure incentive alignment even under stress.

They also checked parameters like fee configuration - it’s essential that this remains precise. Verifying the fee configuration proved that users gain greater reliability and face no unexpected issues.

Human judgment still matters

Automated tools are powerful, but top-tier security requires coupling those tools with experienced human judgment. Certora is best known for formal (automated) verification – mathematical proofs that smart contract logic holds under every possible state. But for this engagement, we commissioned a dedicated manual code review of the Fusion+ cross-chain swap contracts, drawing on the same expert security tools that have protected protocols like Aave, Uniswap and Lido.

The approach is based on thinking like an attacker: evaluating incentives and timing, and catching edge cases before they escalate or affect end users. 

For our users, that translates into:

• More reliable cross-chain swaps
• Reduced edge-case risks
• Stronger system resilience

Our collaboration with Certora was about hardening the infrastructure that lets users swap across 13+ networks without bridges, wrapped tokens, or third-party trust. In DeFi, security isn’t a one-time audit – it’s an ongoing discipline. This review is one part of a broader commitment to keeping 1inch products robust as the protocol evolves.

Reach out to Certora If you want to work with them.