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181 points ekiauhce | 1 comments | | HN request time: 0.314s | source
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ccleve ◴[] No.42224858[source]
I wonder if it would have been possible to win the challenge legitimately?

If a randomly-generated file happened to contain some redundancy through sheer chance, you could hand-craft a compressor to take advantage of it. This compressor would not work in general for random data, but it could work for this one particular case.

It's a bet worth taking, because the payoff, 50:1 ($5,000 to $100), is pretty good. Play the game 50 times and you might get a file you could compress.

The challenge, then, would be for the person offering the bet to generate a really random file that contained no such redundancy. That might not be easy.

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kittoes ◴[] No.42225027[source]
What if we didn't even attempt to compress the file? Theoretically, there is a random number generator + seed combination that would output the same bytes as the source file.
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changoplatanero ◴[] No.42225036[source]
Neat idea but chances are the length of the seed is equal to the length of the original file.
replies(2): >>42225112 #>>42230911 #
guepe ◴[] No.42225112[source]
There is a polynomial expression that will match the file. I wonder if expressing it would be compressible to a lower size than original file? [edit] I’m wrong - not all sequences can be expressed with a polynomial.
replies(1): >>42225802 #
1. l33t7332273 ◴[] No.42225802[source]
This reminds me of a data compression scheme I came up with once:

Treat an n bit file as a polynomial over the finite field with characteristic 2. Now, there are some irreducible polynomials in this field, but many polynomials have factors of x and of (x+1). Factor the polynomial into P(x)x^n (x+1)^m. and just collect these terms, storing only P, n, and m.