2. Determine the key size, in bits, required for a key space containing 1.157x10⁷⁷ keys.

3. Algorithm A has a complexity of 25N² and algorithm B has a complexity of 2.5*2^N. For small values of N algorithm A will perform better than algorithm B. At what value of N will the complexity of algorithm B begin to overtake algorithm A?

4. (a) A total of 92 seconds are required for unencrypted transmission of a large file. When the same file is transferred with encryption, it takes 127 seconds. What is the encryption overhead, as a percentage?

(b) If a second, unencrypted file requires 250 seconds for transmission, what can we expect if it is encrypted?

5. What is the importance of prime numbers in the encryption process?