Non repudiation

In a general sense non-repudiation involves associating actions or changes to a unique individual. For a secure area, for example, it may be desirable to implement a key card access system. Non-repudiation would be violated if it were not also a strictly enforced policy to prohibit sharing of the key cards and to immediately report lost or stolen cards. Otherwise determining who performed the action of opening the door cannot be trivially determined.

The term is often seen in a legal setting wherein the authenticity of a signature is being challenged. In such an instance, the authenticity is being "repudiated".^a

[1] https://en.wikipedia.org/wiki/Non-repudiation

See also

Protocol