A lot of stuff. SHA256 is very slow, and that's no surprise. It's cryptographic after all. Here's a small list of usecases for non-cryptographic hash function

A lot of stuff. SHA256 is very slow, and that's no surprise. It's cryptographic after all. Here's a small list of usecases for non-cryptographic hash functions: - Checksums and error correction codes, as long as there is no way to maliciously use this. - Hash tables. These always use non-cryptographic hash functions. - Bloom filters. - Heuristic fingerprinting. They're not strong enough to be used for normal data fingerprints, but they can be used as a way to decide if two buffers are "probably equal" or "certainly not equal". Hash tables are the main one. Cryptographic hash functions are almost never used in them. SipHash is a popular choice, but it is not cryptographic. That is a misunderstanding: It's a MAC function.