A VHDL implementation of the Hummingbird cryptographic algorithm

Abstract

In this paper a VHDL implementation of the Hummingbird lightweight cryptographic algorithm is presented, with the initialization, encryption and decryption processes analyzed and simulated. All these processes include stream cipher and block cipher encryption or decryption techniques, such as transposition with linear transform and substitution with Substitution box (Sbox). These techniques are described in detail, and a full paradigm is presented. The Hummingbird algorithm exploits the extra safety provided by the Linear Feedback Shift Register (LFSR). Such a circuit is fully designed and analyzed, demonstrating a reliable and well performed system that can implement a successful encryption/decryption process. The analysis of both the forward and the reverse procedure are described together with a case study, using suitable programming via the Xilinx Design Suite. Following the analysis of the Hummingbird algorithm, the LFSR circuit and the whole decryption process circuit are designed from scratch. The results of the simulation proved the reliable execution of the algorithm.