@node en2814789
@section GOST 28147-89 (Magma)

@table @asis
@item Algorithm type
    Block cipher
@item Blocksize
    64 bit
@item Keysize
    256 bit
@item Structure
    Feistel network
@item Rounds
    32
@item RFC
    @itemize
    @item @url{https://tools.ietf.org/html/rfc5830.html, 5830}
    @item @url{https://tools.ietf.org/html/rfc8891.html, 8891} (Magma)
    @end itemize
@item Best attack
    2@sup{224} with 2@sup{32} open-enciphered text pairs.
    Highly depends on used S-boxes
@item Wikipedia
    @url{https://en.wikipedia.org/wiki/GOST_(block_cipher), article}
@end table

@strong{Features}:
@itemize
@item Was developed by KGB in USSR
@item Standard does not define any S-boxes:
    @itemize
    @item There could be backdoors in S-box, if it was defined and fixed
    by the standard.
    @item Secret/private S-box could be used as an additional keying
    information.
    @item You can not determine cipher's strength without knowing the
    exact S-box. Self-made S-boxes can highly affect overall cipher's
    strength.
    @item Implementations using different S-boxes are not interoperable.
    @end itemize
@item You have to be very cautious using that cipher with that small
blocksize and often do rekeying.
@item "Magma" name was issued in @ref{en34122015, Kuznechik} standard.
It is identical to GOST 28147-89, except for fixed S-boxes and slightly
different key and block conversion.
@end itemize

@strong{Implementations}: @ref{2814789Impl, here}.