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From: Chax Plore <ftilojim@tznvy.pbz>
Newsgroups: sci.crypt
Subject: Re: Naive PRNG encryption?
Date: Sat, 22 Feb 2025 13:08:36 +0100
Organization: i2pn2 (i2pn.org)
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On 2024-08-03 12:41, vallor wrote:
> 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.
> 
> How easy is it to crack the resulting "ciphertext"?
> 

Make your PRNG a ChaCha20 and make your seed random and 256-bit,
and you will be OK.

Also: ISAAC seems fit for this job:
https://burtleburtle.net/bob/rand/isaacafa.html

Seed your CSPRNGs using KMACXOF256 on secret key and salt.

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