Lightweight Design Choices for LED-like Block Ciphers

Serial matrices are a preferred choice for building diffusion layers of lightweight block ciphers as one just needs to implement the last row of such a matrix. In this work we analyze a new class of serial matrices which are the lightest possible $4 \times 4$ serial matrix that can be used to build diffusion layers. With this new matrix we show that block ciphers like LED can be implemented with a reduced area in hardware designs, though it has to be cycled for more iterations. Further, we suggest the usage of an alternative S-box to the standard S-box used in LED with similar cryptographic robustness, albeit having lesser area footprint. Finally, we combine these ideas in an end-end FPGA based prototype of LED. We show that with these optimizations, there is a reduction of $16$ in area footprint of one round implementation of LED

Finding Desirable Substitution Box with SASQUATCH

This paper presents ``SASQUATCH\u27\u27, an open-source tool, that aids in finding an unknown substitution box (SBox) given its properties. The inspiration of our work can be directly attributed to the DCC 2022 paper by Lu, Mesnager, Cui, Fan and Wang. Taking their work as the foundation (i.e., converting the problem of SBox search to a satisfiability modulo theory instance and then invoking a solver), we extend in multiple directions (including -- but not limiting to -- coverage of more options, imposing time limit, parallel execution for multiple SBoxes, non-bijective SBox), and package everything within an easy-to-use interface. We also present ASIC benchmarks for some of the SBoxes

Progress in Cryptology – INDOCRYPT 2017 [electronic resource] : 18th International Conference on Cryptology in India, Chennai, India, December 10-13, 2017, Proceedings /

This book constitutes the refereed proceedings of the 18th International Conference on Cryptology in India, INDOCRYPT 2017, held in Chennai, India, in December 2017. The 19 revised full papers presented in this book were carefully reviewed and selected from 75 submissions. The focus of the conference includes works on Public-Key Cryptography, Cryptographic Protocols, Side-Channel Attacks, Implementation of Cryptographic Schemes, Functional Encryption, Symmetric-Key Cryptanalysis, Foundations, and New Cryptographic Constructions.Post-Quantum Cryptography using Module Lattices -- Recent Advances in Function & Homomorphic Secret Sharing -- A note on Ring-LWE security in the case of Fully Homomorphic Encryption -- Architecture level Optimizations for Kummer based HECC on FPGAs -- Bricklayer Attack: A Side-Channel Analysis on the ChaCha Quarter Round -- CCA-secure Predicate Encryption from Pair Encoding in Prime Order Groups: Generic and Efficient -- Cold Boot Attacks on NTRU -- DSA Signing Key Recovery with Noisy Side Channels and Varying Error Rates -- Fast Scalar Multiplication for Elliptic Curves over Binary Fields -- Field lifting for smaller UOV public keys -- Gabidulin matrix codes and their application to small ciphertext size cryptosystems -- Lightweight Design Choices for LED-like Block Ciphers -- Looting the LUTs : FPGA Optimization of AES and AES-like Ciphers for Authenticated Encryption -- Improved Differential Cryptanalysis on Generalized Feistel Schemes -- Improvements for Gate-Hiding Garbled Circuits -- Recovering Short Generators of Principal Fractional Ideals in Cyclotomic Fields of Conductor p_q -- Revisiting a Masked Lookup-Table Compression Scheme.- .This book constitutes the refereed proceedings of the 18th International Conference on Cryptology in India, INDOCRYPT 2017, held in Chennai, India, in December 2017. The 19 revised full papers presented in this book were carefully reviewed and selected from 75 submissions. The focus of the conference includes works on Public-Key Cryptography, Cryptographic Protocols, Side-Channel Attacks, Implementation of Cryptographic Schemes, Functional Encryption, Symmetric-Key Cryptanalysis, Foundations, and New Cryptographic Constructions