(a) Explain the two possible configuration for 3DES.
(b) What is the main disadvantage of 3DES?
(c) Why are most modern symmetric algorithm block ciphers?
(d) Describe four weaknesses of symmetric cryptography.
(e) Consider that Alice have to send bulk data to a remote user Bob.
Explain how Alice would use both asymmetric and symmetric cryptography to achieve both security and efficiency in terms of encryption time.