Question

Which of the following are important differences between digital signatures and message authentication codes (MACs)? (Choose all that apply.)

a. MACs can accept messages of arbitrary length, while digital signatures are limited to messages with sizes less than the RSA modulus

b. Digital signatures can be used to calculate a signature on the encrypted message, but MACs can only be used on the plaintext message before encrypting

c. Digital signatures can enforce integrity, authenticity, and non-repudiation, but MACs can only enforce integrity and authenticity

d. A MAC depends on encrypting the hash with a shared, symmetric key, while a digital signature encrypts the hash using a private key

Answer 1

A,B,C,D

MAC implements integrity and authenticity while Digital signature implements integrity, authenticity, and non-repudiation

All of them are the correct differences