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 it’s predecessor Hummingbird-1, Hummingbird-2 has been targeted for low-end microcontrollers and for hardware implementation in lightweight devices such as RFID tags and wireless sensors. Compared to the previous version of the cipher, and in response to extensive 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. In this paper we present the Hummingbird-2 algorithm, its design and security arguments, performance analysis on both software and hardware platforms, and timing analysis in relation to the ISO 18000-6C protocol.