A seed-independent hash collision in GxHash

For a pangenome deduplication tool I&rsquo;m working on ( pandedup ), I&rsquo;m using 128-bit hashes as &ldquo;unique&rdquo; identifiers of substrings. Sadly, it turns out that gxhash128 (the 128-bit version of gxhash ) has a hash collision between the two strings of length 88 below that only differ in 5 positions, regardless of the value of the seed. Looking at the strings, this clearly…