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From: Phil Carmody <pc+usenet@asdf.org>
Newsgroups: sci.crypt
Subject: Re: Naive PRNG encryption?
Date: Wed, 21 Aug 2024 20:56:46 +0300
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vallor <vallor@cultnix.org> writes:
> I saw someone mention this on another 'froup, and I've thought about it 
> myself.  Is it really "uncrackable"?
>
> Take a plaintext and transform each character with the output
> of a PRNG, with the seed being the key.

That's just a stream cypher.

> How easy is it to crack the resulting "ciphertext"?

If you have more than one encrypted with the same key, probably pretty
easy, depending on the transform.  Just "subtract" (the inverse of the
transform) the two streams from each other, and you'll end up with the
difference between the two plain-texts, which will be highly non-uniform.

Phil
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