Authenticate (5)
'authenticate' is the definition.
(I know that authenticate is a more specific form of attest)
This is all the clue.
(Other definitions for prove that I've seen before include "Verify" , "Show to be true" , "Demonstrate (truth)" , "Demonstrate to be true" , "Ascertain" .)
'authenticate' is the definition.
(I know that authenticate is a more specific form of certify)
This is all the clue.
(Other definitions for certify that I've seen before include "Authorise officially" , "Formally confirm" , "Declare; endorse" .)