Repudiation

Definition
Repudiation is

"[t]he ability of a user to deny having performed an action that other parties cannot prove otherwise. For example, a user who deleted a file can successfully deny doing so if no mechanism (such as audit files) can contradict that claim."

Source
U.S. Justice Department, Justice Information Privacy Guideline - Developing, Drafting and Assessing Privacy Policy for Justice Information Systems, Glossary (Sept. 2002).