Randomness

Perry E. Metzger pmetzger at shearson.com
Wed Jan 27 09:24:28 PST 1993


> From: thug at phantom.com (Murdering Thug)
> 
> Yes I do think the idea of making a "more random than random" stream
> by filtering out long runs of 0's or 1's weakens the the key stream
> in theory, but in practical use it strengthens it, because if the stream
> is left alone, runs of 500 bits of 0's or 1's can come through, and any
> fool can then extract plain text using XOR in this area of the cyphertext.

The odds against a run of 500 1's is one in 2^500th, which is a number so
large I can't imagine a real random number source creating it in the lifetime
of our universe. Presumably, your problem is that your random number source
is crap.

Perry






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