If a key is 43 bits long, how much longer will it take to crack it by exhaustive search if it is extended to 50 bits?
A) 7 times as long
B) 14 times as long
C) 128 times as long
D) 256 times as long

Question

Quizplus · Accepted Answer

The number of possible keys increases exponentially with key length. For every additional bit added to the key, the number of possible keys doubles. Therefore, extending a 43-bit key to 50 bits results in 2^7 (128) times as many possible keys. So, it will take 128 times longer to crack a 50-bit key than a 43-bit key using exhaustive search.

If a Key Is 43 Bits Long, How Much Longer