Suppose we have a computer that can do 2⁵⁰ AES decryptions per second. What is the expected time (in seconds) to find the correct key by brute force search if the AES key setting is 128 bits?
a) 1.20892582 × 10¹⁴ seconds
b) 3.40282367 × 10³⁸ seconds
c) 5.42101086 × 10¹⁸ seconds
d) 7.2057594 × 10¹⁶ seconds
