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Yuji Sakai
2015-12-22 18:37:08 Post No. 4020252
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Yuji Sakai
2015-12-22 18:37:08
Post No. 4020252
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ok so everyone know's that if you XOR an integer with its own rotations AND'd by some values, it can be used to reversibly map every n-bit integer into another, in a cryptographically secure way.
now, everyone also knows that using a linear congruence, e.g. (x*0x1337d+69)%(2^n) can be used to permute through the entire n-bit space by applying it repeatedly.
now, the question is, is there a way to do the latter in a cryptographically secure way? what i mean is that, like the first example, construct an arbitrary function (as big as you want) that is impossible to deduce from a few samples, but actually maps through the entire n-bit space when iterated repeatedly, similar to linear congruence?
