- Sep 28, 2001
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I'm trying to predict the next X bytes of a stream for which I already have a roughly 7500 byte-long sample. The range of values in the stream is a known fixed count.
On sample intervals of 96 bytes or so I can see trends:
Only 55-65% of the posible byte values are used
5-10% of those bytes repeat up to 4 times in the 96-byte sequence
if I sum a fixed count of the bytes the sum is always in a range of 65-220 witht he average falling between 157 and 162
the same byte never appears more than once in the same grouping if I stick to the groupings given out by this black box - length of grouping is known fixed.
the unicity distance between bytes averages between 7 and 8
pairs of bytes repeat frequently, as do some sets of triples
4 and 5-byte groups do not repeat often at all
there has never been a repeat grouping over 5 bytes long
frequency distributions show that over time, the freq. of each given byte falls along the bell curve. This also applies to the frequency of the frequencies and the freq. of the unicity distance over a fixed sample length.
Total problem set size per sample is approximately 17.7 billion combinations
I think I've manged to narrow the problem set down to 750,000 combinations, but currently that doesn't mean anything.
Anyone know how to hack a bell curve?
On sample intervals of 96 bytes or so I can see trends:
Only 55-65% of the posible byte values are used
5-10% of those bytes repeat up to 4 times in the 96-byte sequence
if I sum a fixed count of the bytes the sum is always in a range of 65-220 witht he average falling between 157 and 162
the same byte never appears more than once in the same grouping if I stick to the groupings given out by this black box - length of grouping is known fixed.
the unicity distance between bytes averages between 7 and 8
pairs of bytes repeat frequently, as do some sets of triples
4 and 5-byte groups do not repeat often at all
there has never been a repeat grouping over 5 bytes long
frequency distributions show that over time, the freq. of each given byte falls along the bell curve. This also applies to the frequency of the frequencies and the freq. of the unicity distance over a fixed sample length.
Total problem set size per sample is approximately 17.7 billion combinations
I think I've manged to narrow the problem set down to 750,000 combinations, but currently that doesn't mean anything.
Anyone know how to hack a bell curve?