POSTER: Using Improved Singular Value Decomposition to Enhance Correlation Power Analysis

Cryptographic System-on-Chips (SoCs) are becoming more and more popular. In these systems, cryptographic accelerators are integrated with processor cores to provide users with the software’s flexibility and hardware’s high performance. First, this work aimed to confirm the vulnerability of cryptographic SoCs against several types of power analysis attacks. Then, the novel Random Dynamic Frequency Scaling (RDFS) countermeasure is proposed to improve the resistance of such systems. The proposed RDFS countermeasure improved the power analysis resistance while maintaining low-performance overhead and hardware costs by generating more than 219,000 distinct frequencies for driving only the cryptographic accelerators. The effectiveness of the proposed RDFS countermeasure is demonstrated by conducting realistic Correlation Power Analysis (CPA) attacks, Deep-Learning-based Side-Channel Analysis (DL-SCA) attacks, and Test Vector Leakage Assessment (TVLA) testing methodology. The experimental results show that the RISC-V SoC protected by RDFS countermeasure can withstand CPA attacks and TVLA test with more than five million power traces, which is the best result compared to other related works. The proposed RDFS countermeasure also harden the targeted RISC-V SoC’s resistance against DL-SCA attacks.

In this article, we present a compact implementation of the Salsa20 stream cipher that is targeted towards lightweight cryptographic devices such as radio-frequency identification (RFID) tags. The Salsa20 stream cipher, ann addition-rotation-XOR (ARX) cipher, is used for high-security cryptography in NEON instruction sets embedded in ARM Cortex A8 CPU core-based tablets and smartphones. The existing literature shows that although classical cryptanalysis has been effective on reduced rounds of Salsa20, the stream cipher is immune to software side-channel attacks such as branch timing and cache timing attacks. To the best of our knowledge, this work is the first to perform hardware power analysis attacks, where we evaluate the resistance of all eight keywords in the proposed compact implementation of Salsa20. Our technique targets the three subrounds of the first round of the implemented Salsa20. The correlation power analysis (CPA) attack has an attack complexity of 2 19 . Based on extensive experiments on a compact implementation of Salsa20, we demonstrate that all these keywords can be recovered within 20,000 queries on Salsa20. The attacks show a varying resilience of the key words against CPA that has not yet been observed in any stream or block cipher in the present literature. This makes the architecture of this stream cipher interesting from the side-channel analysis perspective. Also, we propose a lightweight countermeasure that mitigates the leakage in the power traces as shown in the results of Welch’s t -test statistics. The hardware area overhead of the proposed countermeasure is only 14% and is designed with compact implementation in mind.

Side-channel attacks are increasingly recognized as a significant threat to hardware roots of trust. As a result, cryptographic module designers must ensure that their modules are resilient to such attacks before deployment. However, efficient evaluation of side-channel vulnerabilities in cryptographic implementations remains challenging. This paper introduces an open-source framework integrating FPGA designs, power measurement tools, and high-performance side-channel analysis libraries to streamline the evaluation process. The framework provides design templates for two widely used FPGA boards in the side-channel analysis community, enabling Shell-Role architecture, a modern FPGA design pattern. This shell abstraction allows designers to focus on developing cryptographic modules while utilizing standardized software tools for hardware control and power trace acquisition. Additionally, the framework includes acceleration plugins for ChipWhisperer, the leading open-source side-channel analysis platform, to enhance the performance of correlation power analysis (CPA) attacks. These plugins exploit modern many-core processors and graphics processing units (GPUs) to speed up analysis significantly. To showcase the capabilities of the proposed framework, we conducted multiple case studies and highlighted significant findings that advance side-channel research. Furthermore, we compare our CPA plugins with existing tools and show that our plugins achieve up to 8.60x speedup over the state-of-the-art CPA tools.

In this paper, we propose a novel cell-level side channel countermeasure fluctuating power logic (FPL), which diffuses the correlation between the real power consumption and the fixed data transitions by employing a cascade voltage logic. The countermeasure further acts as a cell-level V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DD</inf> randomizer, making it a strong candidate for implementing algorithmic countermeasure and exploiting its noise generation capabilities. This proposed scheme is illustrated by a standard flip-flop. HSPICE based simulation results show that the modified flip-flop is resistant against power analysis at the cost of doubled power dissipation. Two illustrative case studies of PRESENT and AES substitutions have been explored. The resistance against Side-Channel Analysis(SCA) is evaluated by the correlation power analysis. The new logic outperforms other counterparts in consideration of both security and cost, which renders it as a practical solution for resource-constrained systems. The proposed cell-level countermeasure can naturally mitigate other SCA such as electromagnetic analysis.

Most cryptographic systems are secure in theory; however, the implementation of cryptographic system on embedded devices can be attacked by analyzing the power consumption of specific operation to reveal the key. The classic vertical correlation power analysis (CPA) attack requires a large number of power traces for analysis. Using transient secret-key scheme significantly weakens such an attack as insufficient data could be obtained. On the other hand, the horizontal CPA requires at least a single power trace and can make full use of multiple intermediate values to analyze the correlation of power consumption. In this work, we devised a horizontal CPA attack on schoolbook polynomial multiplication of hardware-implemented lattice-based cryptosystem without precise location. The accuracy of correctly recovering any one sub secret-key using only a single trace is 99.90%, and the accuracy of correctly recovering the secret-key is 76.41%. The powerful attack capability of horizontal CPA exposes the vulnerability of unprotected schoolbook polynomial multiplication against the attack of side-channel analysis (SCA).

Cryptographic algorithm implementations need to be secured against side-channel attacks. Correlation Power Analysis (CPA) is an efficient technique for recovering secret key bytes of a cryptographic algorithm implementation by analyzing the power traces of its execution. Although CPA usually does not require a lot of traces to recover secret key bytes, it is no longer true in a noisy environment, for which the required number of traces can be very high. Computation time can then become a major concern for performing this attack and assessing the robustness of an implementation against it.This article introduces FastCPA, which is a correlation computation targeting the same goal as regular CPA, but based on power consumption vectors indexed by plaintext values. The main advantage of FastCPA is its fast execution time compared to the regular CPA computation, especially when the number of traces is high: for 100,000 traces, the speedup factor varies from 70 to almost 200 depending on the number of samples.An analysis of FastCPA accuracy is made, based on the number of correct key bytes found with an increasing noise. This analysis shows that FastCPA performs similarly as the regular CPA for a high number of traces. The minimum required number of traces to get the correct key guess is also computed for 100,000 noisy traces and shows that FastCPA obtains similar results to those of regular CPA. Finally, although FastCPA is more sensitive to plaintext values than the regular CPA, it is shown that this aspect can be neglected for a high number of traces.

This article demonstrates enhanced power (P) and electromagnetic (EM) side-channel analysis (SCA) attack resistance of standard (unprotected) 128-bit advanced encryption standard (AES) engines with parallel (P-AES, 128-bit) and serial (S-AES, 8-bit) datapaths and a 128-bit SIMON engine with the bit-serial (1-bit) datapath by an on-die security-aware all-digital low-dropout (DLDO) regulator. The proposed DLDO improves SCA resistance using control-loop-induced perturbations in a nominal DLDO, enhanced by a random switching noise injector (SNI) by power-stage control and a randomized reference voltage (R-VREF) generator coupled with all-digital clock modulation (ADCM). SCA performed on the measured power/EM signatures acquired from a 130-nm CMOS testchip demonstrates up to 25 $\times $ reduction in test vector leakage assessment (TVLA) leakage for P-AES and 3579 $\times $ , 2182 $\times $ , and 500 $\times $ increase in minimum-traces-to-disclose (MTD) 80% of the subkeys for P-AES, S-AES, and SIMON cores, respectively, with respect to correlation power analysis (CPA) and correlation EM analysis (CEMA).

Power analysis attacks are types of side channel attacks that are based on analyzing the power consumption of the cryptographic devices. Correlation power analysis is a powerful and efficient cryptanalytic technique. It exploits the linear relation between the predicted power consumption and the real power consumption of cryptographic devices in order to recover the correct key. The predicted power consumption is determined by using the appropriate consumption model. Until now, only a few models have been proposed and used. In this paper, we describe the process to conduct the CPA attack against AES on SASEBO-GII board. We present a comparison between the Hamming Distance model and the Switching Distance model, in terms of number of power traces needed to recover the correct key using these models. The global successful rate achieves 100% at 11100 power traces. The power traces needed to recover the correct key have been decreased by 12.6% using a CPA attack with Switching Distance model.

Encryption chips are specialized integrated circuits that incorporate encryption algorithms for data encryption and decryption, ensuring data confidentiality and security. In China, the domestic SM4 algorithm is commonly utilized, as opposed to the international AES encryption algorithm. These widely implemented encryption standards have been proven to be difficult to crack through crypt analysis methods Currently, power consumption side-channel attacks are the most prevalent method. They involve capturing power consumption data during the encryption process and subsequently recovering the encryption key from this data. The two leading methods are Differential Power Analysis (DPA) and machine learning techniques. DPA does not necessitate prior knowledge but relies heavily on the number of power consumption curves. With only 50 power consumption data points, the accuracy is a mere 80%. Machine learning methods require prior knowledge, achieving an accuracy rate above 95% with only 30 power traces, albeit with training times typically exceeding 15 min. In this paper, a distributed energy analysis attack approach was presented based on Correlation Power Analysis (CPA). The power consumption data was divided into 16 subsets, with each subset corresponding to 8 bytes of the key. By training each subset separately, the 8-byte key’s corresponding power consumption data is reduced to only 100 dimensions, resulting in a 76% decrease in cracking time and a 3% improvement in cracking accuracy rate.This article also trains a more complex 256 classification model to directly crack the final key, achieving a success rate of 28% in cracking 128-bit passwords with only 1 power trace

PRESENT, proposed by A. Bogdanov et al. in CHES 2007, is an ultra-lightweight symmetric cipher for extremely constrained environments such as RFID tags and sensor networks. In this article, a representative platform, 0.25 µm 1.8 V standard cell circuit is proposed to complement the PRESENT, the simulation-based ASIC experimental environment is built to acquire power data. According to the fact that the power consumption of a digital circuit implemented in the CMOS technology depends on the data that the circuit is processing, we create the hypothetical circuit model for differential power analysis (DPA) against the special block cipher, PRESENT. Two Different statistical methods, multi-bit DPA and correlation power analysis (CPA), are conducted in this paper to analyze the power data sampled from the power traces. We can attack all secret key bits after first two rounds DPA attack. Our results present the vulnerability to power analysis attack against the hardware implementations of PRESENT.

Cryptographic devices are vulnerable to the nowadays well known side channel leakage analysis. Secret data can be revealed by power analysis attacks such as Simple Power Analysis (SPA), Differential Power Analysis (DPA) and Correlation Power Analysis (CPA). First, we give an overview of DPA in mono-bit and multi-bit cases. Next, the existing multi-bit DPA methods are generalized into the proposed Partitioning Power Analysis (PPA) method. Finally, we focus on the CPA technique, showing that this attack is a case of PPA with special coefficients and a normalization factor. We also propose a method that allows us to improve the performance of CPA by restricting the normalization factor.Keywordsside channelpower analysisDPAmulti-bit DPAPPACPAcorrelationDESAES

IoT devices have very strong requirements on all the resources such as memory, randomness, energy and execution time. This paper proposes a number of scalable shuffling techniques as countermeasures against side channel analysis. Some extensions of an existing technique called Random Start Index (RSI) are suggested in this paper. Moreover, two new shuffling techniques Reverse Shuffle (RS) and Sweep Swap Shuffle (SSS) are described within their possible extensions. Extensions of RSI, RS and SSS might be implemented in a constrained environment with a small data and time overhead. Each of them might be implemented using different amount of randomness and thus, might be fine-tuned according to requirements and constraints of a cryptographic system such as time, memory, available number of random bits, etc. RSI, RS, SSS and their extensions are described using SubBytes operation of AES-128 block cipher as an example, but they might be used with different operations of AES as well as with other algorithms. This paper also analyses RSI, RS and SSS by comparing their properties such as number of total permutations that might be generated using a fixed number of random bits, data complexity, time overhead and evaluates their resistance against some known side-channel attacks such as correlation power analysis and template attack. Several of proposed shuffling schemes are implemented on a 8-bit microcontroller that uses them to shuffle the first and the last rounds of AES-128.&#x0D;

Field-programmable gate arrays (FPGAs) are widely used in many fields because of their low power consumption, easy design and good performance. For applications running on FPGAs, security is very important. A lot of researches have been done on the security issue of FPGA implementations, many attacks and countermeasures have been proposed. The dual complementary strategy is a countermeasure designed to thwart side channel attacks. In this paper, we perform Correlation Power Analysis (CPA) against dual complementary AES implemented on the SAKURA-G FPGA board. For dual complementary AES with constant Hamming Weight (HW) value, which is demonstrated to be robust against CPA based on HW model, we successfully recover the secret key using Hamming Distance (HD) and Switching Distance (SD) models with 2,000 power traces. For dual complementary AES with constant HD, 16,000 resp. 10,000 power traces are required to recover the key with HD resp. SD model.

The Correlation Power Analysis (CPA) is used to compromise the security of crypto systems by measuring and analyzing physical leakage that is the power consumption. Unlike classical cryptanalysis techniques, it requires very less computations to extract the secret information of the cipher systems. But, one of the main hindrances in mounting the CPA attack is the segregation of single power trace of multiple encryptions performed continuously (without pause) among number of traces corresponding to individual encryptions. To overcome this limitation, a new technique is proposed in this paper to split the power traces of AES and DES algorithms running continuously on FPGA. This (energy of samples based algorithm) finds the start of the encryption and computes number of samples in each clock of FPGA. It exploits the repetition of specific patterns available in the traces to determine the encryption length in terms of number of samples. With this information, it splits a power trace of several consecutive encryptions among number of traces corresponding to each encryption. The important thing is that it does not require information about clock frequency of FPGA board and sampling rate of the Oscilloscope. This algorithm was applied on the traces of 25, 50, 100, 125 and 250 samples per clock (when processing was performed at 1, 2 & 4 MHz clock frequencies). In all the cases, the key of AES and DES were retrieved by mounting the CPA attack on splitted traces resulting from the splitting technique.

We propose a Multiplexer Look-Up-Table (MLUT) based Substitution-Box (S-Box) implementation for the Advanced Encryption Standard (AES) algorithm. There are two key features in the proposed MLUT based S-Box. First, it is implemented based on 256-byte to 1-byte multiplexer with a 256-byte memory instead of the conventional implementation of employing multiplication inversion in GF(28) and affine transformation. Thus, our proposed S-Box is simpler in circuit implementation and lower in power dissipation. Second, our S-Box is 30× more secured against the Side Channel Attack (SCA) based on Correlation Power Analysis (CPA), as our proposed S-Box exhibits smaller variance in its power dissipation profile for different processed data. Based on the measurement results of AES-128 implemented on the Sakura-X FPGA board, our proposed S-Box dissipates only 1.9mW and features 5.5× lower power than the conventional S-Box implementation. Our proposed MLUT S-Box design is also highly secured as the CPA attack on the AES with our proposed S-Box implementation requires 13540 power traces. This is significantly higher than the conventional S-Box which requires only 445 power traces to uncover the same secrete key.