Copyright (c) 1997 Bart Massey

[This program is licensed under the "MIT License". Please see the file COPYING in this distribution for license terms.]

These are implementations of the "Ciphersaber" RC4 stream cipher. See the file ciphersaber.html in this distribution for the late-90s webpage describing Ciphersaber, or see the currently-available version. Maybe it's a little silly, but it's a lot of fun.

There are three implementations here:

• A C "reference" implementation I wrote about 1997 is supplied for correctness purposes and as a performance baseline. (I made some cosmetic changes to this code to get it to cleanly compile in 2012.) The code is kind of inelegant, but it works.

• I wrote a more interesting implementation in 2012 in Haskell, using Data.ByteString for the IO and an IOUArray for the RC4 state. It's kind of crufty, and was 14x slower than the C version in 2012, but it works correctly even on large files. (I fixed a bug in 2016, but it should not affect performance.)

• I did a third implementation in 2016 in Rust. It works, but various pieces still need to be pushed upstream before it is stable. I did some more work on it in late 2017. It currently is (temporarily) UNIX-only.

• In 2016 I did a bunch of work/rework, adding "Ciphersaber 2" support (basically 20 repetitions of the key initialization to work around some known security issues) and support for reading the key from /dev/tty to all the implementations.

Enjoy.

Bart Massey
2017-11-27