Simple ways to throw off frequency analysis?
in [Cryptography]
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From: Dave -Turner on 8 Jan 2010 10:28 > but this is presumably not 'simple' in the sense of the original poster. Ouch! :/
From: Greg Rose on 8 Jan 2010 11:44 In article <7-CdneiF-IWt_tvWnZ2dnUVZ8gadnZ2d(a)westnet.com.au>, Dave -Turner <admin(a)127.0.0.1> wrote: >For example, with every byte ... > if byteaddress mod 2 = 1 then > rotate the bits left by x > else > rotate the bits right by x > endif > > >Obviously i'm not after guaranteed security here, just simple ways to add a >decent level of frequency analysis protection with minimal code (the above >example is no doubt a poor one :) as the data being encrypted isn't of high >importance You just made it polyalphabetic, with two related alphabets, so all the standard analysis tools will work. Nothing you can do simply will be much better than polyalphabetic, unless you go to a larger block size (like Playfair). Greg. -- Greg Rose 232B EC8F 44C6 C853 D68F E107 E6BF CD2F 1081 A37C
From: Phil Carmody on 9 Jan 2010 08:55
"Dave -Turner" <admin(a)127.0.0.1> writes: > Say I've encrypted a string with a monoalphabetic cipher (so I haven't used > a polyalphabetic cipher to begin with nor do I want to at any stage) > > What are some simple things I can do to throw off frequency analysis? Compress before encrypting. Phil -- Any true emperor never needs to wear clothes. -- Devany on r.a.s.f1 |