Question 1:

1 What are the essential ingredients of a symmetric cipher?

2 What are the two basic functions used in encryption algorithms?

3 How many keys are required for two people to communicate via a symmetric cipher?

4 What is the difference between a block cipher and a stream cipher?

5 What are the two general approaches to attacking a cipher?

6 Why do some block cipher modes of operation only use encryption while others use both encryption and decryption?

7 What is triple encryption?

8 Why is the middle portion of 3DES a decryption rather than an encryption?

Question:2

1 List three approaches to message authentication.

2 What is a message authentication code?

3. What properties must a hash function have to be useful for message authentication?

4. In the context of a hash function, what is a compression function?

5. What are the principal ingredients of a public-key cryptosystem?

6. List and briefly define three uses of a public-key cryptosystem.

7. What is the difference between a private key and a secret key?

8. What is a digital signature?

Answer rating: 100% (QA)

1 1 There are five ingredients of a symmetric cipher as follows aPlaintext the original comprehensible data or message normally fed into algorithm as input bEncryption algorithm this does a number of ... View the full answer