1. A computer-implemented method comprising: obtaining, by a computing system, at least one content item for which a hash value is to be generated; generating, by the computing system, a set of n-grams based at least in part on the at least one content item; generating, by the computing system, a first vector based at least in part on the set of n-grams, wherein the vector maintains respective counts of n-grams in the set of n-grams; determining, by the computing system, a quantized vector based at least in part on the first vector and one or more parameters; and generating, by the computing system, the hash value for the at least one content item based at least in part on the quantized vector.