3.Consider the brute-force attack.

a. Assume the keys used in a cryptosystem are 10 bits long and it needs 1 second to test an individual key by using the brute-force attack. In the worst case, how much time would it take for the attacker to determine a particular key?

b. If the time needed to test an individual key reduces to 0.001 second, how much time would it take now to determine a particular key by using the brute-force attack in the worst case?

c. If we increase the length of the keys to 20 bits and the time needed to test an individual key is still 0.001 second. How much time would it take now to determine a particular key by using the brute-force attack in the worst case?

d. What can you observe from Questions a-c?