Adiantum: encryption for the low end

It’s worth noting that Adiantum is not a new encryption algorithm as such; instead, it is a repackaging of the ChaCha stream cipher that makes it useful for disk encryption. HPolyC was the original algorithm that Biggers and Crowley were planning to use as a Speck replacement; it was already faster than Speck but some further refinements led to Adiantum and even better performance. The Poly1305 message authentication code (MAC) hash family is used by both, but Adiantum first uses a hash from the NH family of hashes to effectively compress the data by 32x first.

Source: lwn.net