0

While reading about the Davies-Meyer mode (and other modes), I have got some doubts:

  1. What can I use as the key to the encryption $E$? Since I am generating hash of a message (not MAC), then there should not be any secret key involved.
  2. What is the initial hash value ($H_0$)? Can I take it as some public value (IV/nonce) so that it can be changed, or I can set it to be a randomly chosen constant? Related question
  3. (To the previous questions) Can the message $M$ is chosen as the key to $E$? Can $M$ be chosen as $H_0$? Can $M$ be chosen as the key to $E$ and as $H_0$?
  4. Say, I want to use AES as $E$ (which gives 128-bit output), then it is true the Davies-Meyer output is compulsorily of 128 bits?
hola
  • 613
  • 6
  • 23

0 Answers0