Re^8: How to generate different random numbers?

Unless you enumerate all of the permutations of the set, I don't know how this could possibly work.

That's exactly what I'm doing; there is no need to limit yourself to individually selected numbers. If you treat each shuffled set as a random selection from the set of all possible shuffles, then you have a perfectly good random number, equivalent to a randomly selected integer from 1 to N!. If you do M shuffles, you can select random numbers from a set of size N! ^ M. It doesn't take a very large N and/or M to reach the cardinality needed from cryptographic applications.

Comment on Re^8: How to generate different random numbers?

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Re^9: How to generate different random numbers? by thor (Priest) on Sep 08, 2004 at 22:01 UTC
This works in theory. I think that it would become pretty unwieldy in practice though. Given a permutation of a set (let's say {5 1 3 2 4}), which permutation is that of {1 2 3 4 5}? The fourteenth or the forty-second? Wouldn't you have to pre-compute and store all of the permutations for this to work? thor `Feel the white light, the light within Be your own disciple, fan the sparks of will For all of us waiting, your kingdom will come`	[reply]
Re^10: How to generate different random numbers? by Pragma (Scribe) on Sep 08, 2004 at 22:14 UTC
Yes, in practice, it would be absurd. I never claimed that this would be a good way to generate random numbers. I was merely responding to the misguided belief that a random shuffle was somehow any less random than a random selection from a finite set. It is not, and the theoretical ability to generate random numbers from a shuffle is what proves the point. QED, etc etc.	[reply]