There's no doubt you did it - Nonrepudiation - CISSP Study Corner 

What is nonrepudiation?
In cybersecurity, nonrepudiation refers to a state in which an individual is unable to deny having taken a particular action.
It is an important building block for developing a robust cybersecurity program. Nonrepudiation must be closely aligned to strong identification, authentication, authorization, access control, and auditing to be effective.
In this video, we explain how nonrepudiation can actually be achieved in an environment and show you a hands on lab explaining the subject.
Enjoy!