Which of the following concepts is enforced by certifying that email communications have been sent by who the
message says it has been sent by?

A.
Key escrow

B.
Non-repudiation

C.
Multifactor authentication

D.
Hashing

Explanation:
Regarding digital security, the cryptological meaning and application of non-repudiation shifts to mean:
A service that provides proof of the integrity and origin of data.
An authentication that can be asserted to be genuine with high assurance.