Schwaemm, Authenticated Encryption with Associated Data
Schwaemm is an Authenticated Encryption with Associated Data (AEAD) algorithm that uses the Sparkle permutation in a specific mode. Several versions exist, each providing a specific security level and requiring a permutation operating on a specific block size. The following table summarizes the proposed instances of the family. Here, \(n\) denotes the size of the permutation (in bits), \(r\) denotes the rate, \(c\) denotes the capacity,
\(|K|, |N|, |T|\) denote the sizes of key, nonce and tag respectively.
The difference between the instances is the version of the underlying
Sparkle permutation (and thus the rate and capacity is different) and the size of
the authentication tag. The following figure shows the structure on the example of