Visible to the public Extracting Side-Channel Leakage from Round Unrolled Implementations of Lightweight Ciphers

TitleExtracting Side-Channel Leakage from Round Unrolled Implementations of Lightweight Ciphers
Publication TypeConference Paper
Year of Publication2019
AuthorsChawla, Nikhil, Singh, Arvind, Rahman, Nael Mizanur, Kar, Monodeep, Mukhopadhyay, Saibal
Conference Name2019 IEEE International Symposium on Hardware Oriented Security and Trust (HOST)
Keywordsadvanced encryption standard, AES, AES algorithm, Band-pass filters, Ciphers, combinational logics, Correlation, correlation frequency analysis, cryptography, edge nodes, Encryption, Energy efficiency, field programmable gate arrays, Filtering, first-order side-channel leakages, FPGA, fully-unrolled datapath, Hardware, improved CFA attack, leakage models, Lightweight Ciphers, lightweight cryptographic algorithms, multiband narrow bandpass filtering techniques, narrow bandpass filtering, optimal leakage models, parallel round-based datapath, PRINCE, pubcrawl, Resiliency, resource constraints, round unrolled implementations, round unrolling, Scalability, side channel analysis, side channel analysis attacks, side channel signatures, side-channel leakage, signal isolation, Signal to noise ratio, signal-to-noise ratio, SIMON, SIMON datapaths, size 45.0 nm, SNR, time domain correlation power analysis

Energy efficiency and security is a critical requirement for computing at edge nodes. Unrolled architectures for lightweight cryptographic algorithms have been shown to be energy-efficient, providing higher performance while meeting resource constraints. Hardware implementations of unrolled datapaths have also been shown to be resistant to side channel analysis (SCA) attacks due to a reduction in signal-to-noise ratio (SNR) and an increased complexity in the leakage model. This paper demonstrates optimal leakage models and an improved CFA attack which makes it feasible to extract first-order side-channel leakages from combinational logic in the initial rounds of unrolled datapaths. Several leakage models, targeting initial rounds, are explored and 1-bit hamming weight (HW) based leakage model is shown to be an optimal choice. Additionally, multi-band narrow bandpass filtering techniques in conjunction with correlation frequency analysis (CFA) is demonstrated to improve SNR by up to 4x, attributed to the removal of the misalignment effect in combinational logics and signal isolation. The improved CFA attack is performed on side channel signatures acquired for 7-round unrolled SIMON datapaths, implemented on Sakura-G (XILINX spartan 6, 45nm) based FPGA platform and a 24x reduction in minimum-traces-to-disclose (MTD) for revealing 80% of the key bits is demonstrated with respect to conventional time domain correlation power analysis (CPA). Finally, the proposed method is successfully applied to a fully-unrolled datapath for PRINCE and a parallel round-based datapath for Advanced Encryption Standard (AES) algorithm to demonstrate its general applicability.

Citation Keychawla_extracting_2019