Re: difference between AES and AESnnn

[Jari Ruusu <jari.ruusu@pp.inet.fi>]

rkelly@elbow.com wrote:
> aha, so when using just "AES", the password length itself determines the
> number of key bits to encrypt

Yes.

> if i use "losetup -e AES -S xxxxxx<-N->xxxxxxx" (meaning N characters for
> seed) and then password with M characters, will the AES crypt bit size be
> determined by N, by M or somehow by their combination ? Or which ever is
> greater / smaller will determine the crypt bit size ?

For loop-AES' obsolete encryption type AES (without numbers), number of bits
used for encryption is determined by length of M+N:

  128 bit encryption is used for M+N of less than 32
  192 bit encryption is used for M+N of 32...42
  256 bit encryption is used for M+N of more than 42

Loop-AES obsolete encryption type AES (without numbers) exists only for
backward compatibility with some old version. For new setups, _please_ use
AES128, AES192 or AES256 encryption type. Due to creation of unified
(loop-AES + kerneli.org) util-linux, loop-AES' obsolete encryption type
'AES' (without numbers) may be renamed to 'AES-unhashed' in future, so
please avoid using it.

Regards,
Jari Ruusu <jari.ruusu@pp.inet.fi>

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