In this paper we propose a reconfigurable lightweight Internet Protocol Security (IPSec) hardware core. Our architecture supports the main IPSec protocols; namely Authentication Header (AH), Encapsulating Security Payload (ESP), and Internet Key Exchange (IKE). In this work, the cryptographic algorithms and their modes of operation, which are at the heart of the IPSec protocols, are implemented in hardware. Instead of re-implementing common IPSec configurations, which are deemed “too heavy” for pervasive devices, we evaluate efficient implementations of standardized and/or well-known lightweight and hardware-friendly algorithms. In particular, we examine different versions of Present, Grøstl, Photon, and a very compact ECC core. As a consequence, we present IPSecco, a core with adequate security and only moderate resource requirements, making it suitable for lightweight devices. We selected the Xilinx Spartan family of Field Programmable Gate Arrays (FPGA) as target platform due its low-power footprint and reduced costs compared to other FPGAs. Our results show that it is possible to realize a high performance IPSec core even on members of the Spartan-3 family.

In this article, we introduce a novel approach to achieving lightweight device authentication through the use of a low-complexity Convolutional Neural Network (CNN). In our work, we improve the False Authentication Rate (FAR) by transforming the standard CNN into a Bayesian CNN (BCNN or BNN). This transformation enables the use of probabilistic modelling techniques, increasing the model’s robustness and its confidence in authentication decisions. Regardless of the model used, clients authenticate with a retention-based Dynamic Random Access Memory Physical Unclonable Function (DRAM PUF) response. Our approach integrates the low computational complexity of the CNN with the intrinsic security characteristics of the DRAM PUF, offering a robust solution for lightweight and secure device authentication.

Authenticated encryption (AE) has been a vital operation in cryptography due to its ability to provide confidentiality, integrity, and authenticity at the same time. Its use has soared in parallel with widespread use of the internet and has led to several new schemes. There have been studies investigating software performance of various schemes. However, the same is yet to be done for hardware. We present a comprehensive survey of hardware (specifically ASIC) performance of the most commonly used AE schemes in the literature. These schemes include encrypt-then-MAC combination, block-cipher-based AE modes, and the recently introduced permutation-based AE scheme. For completeness, we implemented each scheme with various standardized block ciphers and/or hash algorithms, and their lightweight versions. Our evaluation targets minimizing the time-area product while maximizing the throughput on an ASIC platform. We used 45nm NANGATE Open Cell Library for syntheses. We present area, speed, time-area product, throughput, and power figures for both standard and lightweight versions of each scheme. We also provide an unbiased discussion on the impact of the structure and complexity of each scheme on hardware implementation. Our results reveal 13%--30% performance boost in permutation-based AE compared to conventional schemes, and they can be used as a benchmark in the ongoing AE competition CAESAR.

Modern cryptography today is substantially involved with securing lightweight (and pervasive) devices. For this purpose, several lightweight cryptographic algorithms have already been proposed. Up to now, the literature has focused on hardware-efficiency while lightweight with respect to software has barely been addressed. However, a large percentage of lightweight ciphers will be implemented on embedded CPUs- without support for cryptographic operations. In parallel, many lightweight ciphers are based on operations which are hardware-friendly but quite costly in software. For instance, bit permutations that accrue essentially no costs in hardware require a non-trivial number of CPU cycles and/or lookup tables in software. Similarly, S-Boxes often require relatively large lookup tables in software. In this work, we try to address the open question of efficient cipher implementations on small CPUs by introducing a non-linear/linear instruction set extension, to which we refer to as NLU, capable of implementing on-linear operations expressed in their algebraic normal form(ANF) and linear operations expressed in binary "matrix multiply-and-add" form. The proposed NLU is targeted for embedded micro controllers and it is therefore 8-bit wide. However, its modular architecture allows it to be used in16, 32, 64 and even 4-bit CPUs. We furthermore present examples of the use of NLU in the implementation of standard cryptographic algorithms in order to demonstrate its coding advantage.