# Brute force strategy

I am a beginner in this field, and I was thinking about brute force strategies to break symmetric key encryption.

Let's say we have a block cipher in CTR mode and the key is 56 bits in size. What would a process of finding the key look like (brute forced strategy)?

• It seems you want to work on DES, see the historical machines on DES here and note that some of today's supercomputers can deal with less than an hour. Feb 13 '21 at 17:47
• The RSA DES challenges are nice examples. You need at least one known-plaintext to execute the attack, possibly more than one. Now, considering that you tagged CTR, are you going to execute crib-dragging on the CTR mode that requires that the $(key, IV)$ pair is used again? Feb 13 '21 at 18:00