Cipher Jedi

http://ciphersaber.gurus.com/

In George Lucas' Star Wars trilogy, Jedi Knights were expected to make their own light sabers. The message was clear: a warrior confronted by a powerful empire bent on totalitarian control must be self-reliant. As we face a real threat of a ban on the distribution of strong cryptography, in the United States and possibly world-wide, we should emulate the Jedi masters by learning how to build strong cryptography programs all by ourselves. If this can be done, strong cryptography will become impossible to suppress. </excerpt>

Thus CipherSaber?-1 is borne as is RC4 (ArcFour?) From

1. The CipherSaber?-1 encryption algorithm is RC4 as published in the beginning of Chapter 17 of Applied Cryptography, Second Edition, by Bruce Schneier, John Wiley & Sons, New York, 1996. RC4 is on page 397 in the English edition, ISBN 0-471-11709-9 . Also see the CipherSaber? FAQ.

<excerpt> RC4 [ArcFour?] is simple to describe. The algorithm works in OFB: The keystream is independent of the plaintext. It has a 8 * 8 SBox: s0, s1, ..., s255. The entries are a permutation of the numbers 0 through 255, and the permutation is a function of the variable-length key. It has two counters, i and j, initialized to 0. To generate a random byte [cipher], do the following:

    i = (i + 1) mod 256
    j = (j + si) mod 256
    swap si and sj
    t = (si + sj) mod 256
    k = st

The byte k is XORed with the plaintext to produce ciphertext or XORed with the ciphertext to produce plaintext. Encryption is fast -- about 10 times faster than DES.

Initializing the SBox is also easy. First, fill it linearly: s0=0, s1=1, ..., s255=255. Then fill another 256-byte array with the key, repeating as necessary to fill the entire array: k0, k1, ..., k255. Set the index j to zero. Then:

    for i=0 to 255:
        j=(j + si + ki) mod 256
        swap si and sj

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The above ciphersaber algorithm pretty much requires a computer. Is it possible to build reasonably secure encryption algorithms that *don't* require a computer -- that can be done "by hand"?

http://metaweb.com/wiki/wiki.phtml?title=Pontifex [broken link, Tue Mar 20 00:00:04 PDT 2007]

Is this page titled 'Cipher Jedi' because so few people can spell 'saber'?

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The message was clear: a warrior confronted by a powerful empire bent on totalitarian control must be self-reliant.

The analogy falls completely flat when you consider that Jedi were building their own tools long before the existence of the Empire. There are plenty of reasons to have the ability to build your own tools. An "Evil Empire" ranks way down on the list.

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Preceded the Empire, the Jedi have, but the Jedi anticipated several scenarios, including local falling of civilisation, and the idea that one, or more than one totalitarian regimes, the Jedi religion might survive. From within and without, Enemies come, and the more important your task the more vital preparedness against enemies and obstacles is.