The type of token device that employs a challenge response mechanism is which ofthe following?

A.
One-time password generator

B.
Token generator

C.
Synchronous

D.
Asynchronous

Explanation:
A token device using an asynchronous token-generating method employs achallenge/response scheme to authenticate the user. this situation, theauthentication server sends the user a challenge, a random value also called anonce. The user enters this random value into the token device, which encrypts itand returns a value the user uses as a one-time password. The user sends this value,along with a username, to the authentication server. If the authentication servercan decrypt the value and it is the same challenge value sent earlier, the user isauthenticated.