The Hummingbird-2 Lightweight Authenticated Encryption Algorithm
Hummingbird-2 is an encryption algorithm with a 128-bit secret key and a 64-bit initialization vector. Hummingbird-2 optionally produces an authentication tag for each message processed. Like its predecessor Hummingbird-1, Hummingbird-2 has been targeted for low-end microcontrollers and for hardware implementation in light-weight devices such as RFID tags and wireless sensors. Compared to the previous version of the cipher, and in response to analysis, the internal state has been increased to 128 bits and a flow of entropy from the state to the mixing function has been improved.