Non-repudiation is the assurance that someone cannot successfully deny the validity of something. Typically, non-repudiation refers to the ability to ensure that a party to a contract or a communication cannot refuse the authenticity of their signature on a document or that a message was actually sent.

What is the principle of non-repudiation?

Definition(s): Assurance that the sender of information is provided with proof of delivery and the recipient is provided with proof of the sender's identity, so neither can later deny having processed the information.

How is non-repudiation achieved?

There are two types of security mechanisms for generating non-repudiation evidence: secure envelopes and digital signatures. A secure envelope provides protection of the origin and the integrity of a message based on a shared secret key between communication parties.