5 AEAD Algorithms

Authenticated encryption (AE) schemes are methods using a shared key to transform a message (M) into a ciphertext (C). This process ensures that C not only keeps the message private but also verifies its authenticity.

As researchers analyzed existing AE schemes, they recognized that not all data needs encryption. Many applications involve a mix of secret and non-secret data, so it would be helpful to have a method that ensures privacy for secret data while also verifying authenticity for both types of data. This led to the development of authenticated encryption with associated data (AEAD). The non-secret data is referred to as associated data (AAD) or the header.

CCM and EAX are two-pass schemes, meaning they require two steps: one for privacy and another for authenticity. EAX is generally simpler and more efficient compared to CCM.