# 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.

All instances use (a slight variation of) the Beetle mode of operation presented, which is based on the well-known SpongeWrap AEAD mode.

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 `Schwaemm256-128`

.