Mar 13, 2025

The filter is Poisson distributed by simply selecting the count of bits from any byte in the insert key (point) sha256 hash. Mod 7 of any sha256 byte should obtain positions 0,1,2,3,4,5,6,7 with Poisson distribution. Given that this is filtering only a single bucket, and bucket lengths don’t exceed 14, and are are massively weighted toward 0, 1, 2, 3 lengths, this gives us and excellent false positive rate, and still ensures no false natives across the bucket elements (conflict stack).