more update: flipping half the bits with xor is analytically breakable for repeated use on same document where changes are small. modulo solution does not have same weakness.

... but both you and tobyink were discussing a one-time pad. AFAIK, repetition is a common way to break encryption schemes and it's a substantial part of how the Enigma machine was broken. Although I'm not an expert and open to being proven wrong, I'd be willing to bet the modulo solution is breakable in a similar way to XOR if the pad is re-used.

In reply to Re^4: crypto with core modules only by haukex
in thread crypto with core modules only by morgon

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