Definition
Non-repudiation
Assurance that a signer cannot credibly deny having signed later on.
In Depth
This is a formal way of saying "you can't wriggle out of it." The technology ties a signature to its author strongly enough that a third party can verify it, so a claim of "that wasn't me" doesn't hold up. It is one of the main reasons organizations trust digital signatures for high-stakes agreements, and it works hand in hand with audit trails and timestamps.
Consistent across the US, UK and EU. It is a security property rather than a legal term, so the definition does not vary. In practice the higher EU and UK signature tiers are designed to deliver stronger non-repudiation than a basic signature.
Sources
- NIST Computer Security Resource Center Glossary - A service that is used to provide assurance of the integrity and origin of data in such a way that the integrity and origin can be verified and validated by a third party as having originated from a specific entity in possession of the private key. Official Guidance csrc.nist.gov/glossary/term/non_repudiation