1
vote
1answer
37 views

Process of dividing 168bit key into 56bit keys in TripleDES

I used TripleDES so many times but never thought about this. In TripleDES it requires 168bit ...
3
votes
2answers
190 views

Have these compositions of block ciphers the same security?

I'm interested by the compositions of the block cipher DES, instantiated with independent keys $k_1$, $k_2$ and $k_3$. Are these 3 compositions equivalent in terms of security? ...
1
vote
1answer
966 views

How can 3DES encryption use decryption in the middle step?

I have been reading about the 3DES algorithm and I cannot understand one part. In 3DES we do following operation: $$C=E[K_3,D[K_2,E[K_1,P]]].$$ Where $C$ is ciphertext, $P$ is plaintext, $E$ is DES ...
4
votes
1answer
162 views

Does anyone have a KAT for 3DES KO-2?

Does any one have, or can refer to a Known-Answer-Test (KAT) for Triple DES Keying Option 2? (Keying Option 2 means $C = DES_{k_1}(DES^{-1}_{k_2}(DES_{k_1}(P)))$ for encryption and $P = ...