Which of the following security technologies’ strength is built upon being collision free?

A.
Hash

B.
Digital signatures

C.
Encryption

D.
Decryption

Explanation:
If a hashing algorithm creates the same message digest value for two
different messages, this is considered a collision. Collisions are used in birthday
attacks. Hashing algorithms with longer message digest values are less susceptible
to collisions and birthday attacks.