[PATCH net-next 4/5] crypto: fcrypt - Remove support for FCrypt block cipher

[Geert Uytterhoeven]

On Tue, 28 Apr 2026 at 04:49, Eric Biggers <ebiggers at kernel.org> wrote:
> Remove the insecure FCrypt block cipher from the crypto API.  Its only
> user was net/rxrpc/, but now net/rxrpc/ implements it locally.  The
> crypto API implementation is no longer needed.
>
> For some additional context: FCrypt was designed in 1988 and is
> essentially a weakened version of DES.  It has the same 56-bit key size
> as DES, which is easily brute forced.  Moreover, it's cryptographically
> weak and doesn't even provide the intended 56-bit security level.  Its
> author considers it to be a mistake, as well
> (https://lists.openafs.org/pipermail/openafs-devel/2000-December/005320.html).
>
> But fortunately this 1980s-era homebrew block cipher was never adopted
> outside of net/rxrpc/.  So its code can just be kept there.
>
> Signed-off-by: Eric Biggers <ebiggers at kernel.org>

>  arch/m68k/configs/amiga_defconfig           |   1 -
>  arch/m68k/configs/apollo_defconfig          |   1 -
>  arch/m68k/configs/atari_defconfig           |   1 -
>  arch/m68k/configs/bvme6000_defconfig        |   1 -
>  arch/m68k/configs/hp300_defconfig           |   1 -
>  arch/m68k/configs/mac_defconfig             |   1 -
>  arch/m68k/configs/multi_defconfig           |   1 -
>  arch/m68k/configs/mvme147_defconfig         |   1 -
>  arch/m68k/configs/mvme16x_defconfig         |   1 -
>  arch/m68k/configs/q40_defconfig             |   1 -
>  arch/m68k/configs/sun3_defconfig            |   1 -
>  arch/m68k/configs/sun3x_defconfig           |   1 -

Acked-by: Geert Uytterhoeven <geert at linux-m68k.org> # m68k

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds