- Explain in detail why a public key embedded in a digital certificate is much harder to tamper with than the public key alone?

- What is the purpose of a key exchange algorithm? With what type of cryptosystem is such an algorithm needed?

- In the Unites States, organizations sometimes use Social Security Number or a part of it as an authenticator. Is this a good or bad idea? Explain your answer.

- Briefly describe how the techniques of public key cryptography can be used to implement a digital signature. Be sure you distinguish correctly the use of public and private keys.

- Explain why using a computationally intensive (i.e. slow) hash algorithm is important when storing password data.