3.1 List three approaches to message authentication.3.2 What is a message authentication code?3.4 What properties must a hash function have to be useful for message authentication?3.5 In the context o

3.1 List three approaches to message authentication.3.2 What is a message authentication code?3.4 What properties must a hash function have to be useful for message authentication?3.5 In the context of a hash function, what is a compression function?3.6 What are the principal ingredients of a public-key cryptosystem?3.7 List and briefly define three uses of a public-key cryptosystem.3.8 What is the difference between a private key and a secret key?3.9 What is a digital signature?