International Association
for Cryptologic Research

To mitigate cybersecurity breaches, secure communication is crucial for the Internet of Things (IoT) environment. Data integrity is one of the most significant characteristics of security, which can be achieved by employing cryptographic hash functions. In view of the demand from IoT applications, the National Institute of Standards and Technology (NIST) initiated a standardization process for lightweight hash functions. This work presents field-programmable gate array (FPGA) implementations and carefully worked out optimizations of four Round-3 finalists in the NIST standardization process. A novel compact PHOTON-Beetle implementation is proposed wherein the underlying matrix multiplication is executed in serialized fashion to achieve a small hardware footprint. SPARKLE implementations are carried out by implementing the ARX-box in serialized, parallelized, and hybrid approaches. For Ascon and XOODYAK, the proposed implementations compute certain permutation rounds in one clock cycle in order to explore the trade-off between computation time and hardware area. As a result, this work achieves the smallest hardware footprint for PHOTON-Beetle consuming an area 3.4× smaller than state-of-the-art implementations. Ascon and XOODYAK are implemented in a flexible manner that achieves throughput-to-area (TP/A) ratios 1.8× and 3.9× higher, respectively, compared to implementations found in the literature. In addition, we propose the first FPGA implementations for the SPARKLE hash function. These efficient implementations provide guidelines for choosing a suitable architecture for applications in demand that can be employed in the IoT environment to achieve data integrity for various applications.