Non-Repudiation

Non-repudiation ensures that a party cannot deny having performed a specific action — such as sending a message, signing a document, or authorizing a transaction. It provides proof of the origin and integrity of data, preventing someone from later claiming 'I didn't do that' or 'I didn't send that.'

Non-repudiation is typically achieved through digital signatures, audit logs, and timestamps. When a user digitally signs a document with their PKI certificate, there's cryptographic proof that they signed it — they can't later deny it. Similarly, detailed audit logs with user identification provide evidence of who did what and when.