I wonder if using an operation other than XOR on the bit
representations of pairs of letters would lead to "the other half" of
the message. Perhaps AND, OR, NAND etc.
For the sake of argument suppose this bit operator is called
"XYZ". The idea here is that I'm guessing Gamer split the
plaintext into two halves. So far, Charlie has found the "first
18 letters" of the plaintext by using the XOR operator on the 36 letter
ciphertext, two letters at a time:
s XOR k = x
a XOR n = o
k XOR y = r
suppose the first 3 letters of "the second half" of the message are
"asp", which I'm picking at random. (It's another snake name, and
snakes are fun). Then our mythical bit operator would result in:
s XYZ k = a
a XYZ n = s
k XYZ y = p
So to use this encryption method to encode, say, a 36 letter plaintext,
Gamer would have needed to find two letters (in this case "s" and "k")
such that XOR'ing them gives the first letter ("x") and XYZ'ing them
gives the 19th letter ("a").
Unfortunately, I don't think this would work in general unless the XOR
and XYZ operators were completely independent of each other.
Anyone care to weigh in on this idea?

Posted by Larry
on 20051023 18:07:47 