Question

Assume we perform a known-plaintext attack against DES with one pair of plaintext and ciphertext. How many keys do we have to test in a worst-case scenario if we apply an exhaustive key search in a straightforward way? How many on average?

Answer 1

`2^(55)` keys in a worst case scenario

Step-by-step explanation:

So, Average will be :
`2^(56) /2`

`2^(55)`(Answer)