Residual Vulnerabilities to Power side channel attacks of lightweight ciphers cryptography competition Finalists

The protection of communications between Internet of Things (IoT) devices is of great concern because the information exchanged contains vital sensitive data. Malicious agents seek to exploit those data to extract secret information about the owners or the system. Power side channel attacks are of great concern on these devices because their power consumption unintentionally leaks information correlatable to the device\u27s secret data. Several studies have demonstrated the effectiveness of authenticated encryption with advanced data, in protecting communications with these devices. A comprehensive evaluation of the seven (out of 10) algorithm finalists of the National Institute of Standards and Technology (NIST) IoT lightweight cipher competition that do not integrate built‐in countermeasures is proposed. The study shows that, nonetheless, they still present some residual vulnerabilities to power side channel attacks (SCA). For five ciphers, an attack methodology as well as the leakage function needed to perform correlation power analysis (CPA) is proposed. The authors assert that Ascon, Sparkle, and PHOTON‐Beetle security vulnerability can generally be assessed with the security assumptions “Chosen ciphertext attack and leakage in encryption only, with nonce‐misuse resilience adversary (CCAmL1)” and “Chosen ciphertext attack and leakage in encryption only with nonce‐respecting adversary (CCAL1)”, respectively. However, the security vulnerability of GIFT‐COFB, Grain, Romulus, and TinyJambu can be evaluated more straightforwardly with publicly available leakage models and solvers. They can also be assessed simply by increasing the number of traces collected to launch the attack

On Side-Channel Vulnerabilities of Bit Permutations: Key Recovery and Reverse Engineering

Lightweight block ciphers rely on simple operations to allow compact implementation. Thanks to its efficiency, bit permutation has emerged as an optimal choice for state-wise diffusion. It can be implemented by simple wiring or shifts. However, as recently shown by Spectre and Meltdown attacks, efficiency and security often go against each other. In this work, we show how bit permutations introduce a side-channel vulnerability that can be exploited to extract the secret key from the cipher. Such vulnerabilities are specific to bit permutations and do not occur in other state-wise diffusion alternatives. We propose Side-Channel Assisted Differential-Plaintext Attack (SCADPA) which targets this vulnerability in bit permutation operation. SCADPA is experimentally demonstrated on PRESENT-80 on an 8-bit microcontroller, with the best case key recovery in 17 encryptions. The attack is then extended to latest bit-permutation based cipher GIFT, allowing full key recovery in 36 encryptions. We also propose and experimentally verify an automatic threshold method which can be easily applied to SCADPA, allowing automation of the attack. Moreover, SCADPA on bit permutations has other applications. Application for reverse engineering secret sboxes in PRESENT-like proprietary ciphers is shown. We also highlight a special case, where fixing one vulnerability opens another one. This is shown by applying SCADPA on some assembly level fault attack countermeasures, rendering it less secure than unprotected implementations. Lastly, we also provide several different attack scenarios, such as targeting different encryption modes

Systematic Characterization of Power Side Channel Attacks for Residual and Added Vulnerabilities

Power Side Channel Attacks have continued to be a major threat to cryptographic devices. Hence, it will be useful for designers of cryptographic systems to systematically identify which type of power Side Channel Attacks their designs remain vulnerable to after implementation. It’s also useful to determine which additional vulnerabilities they have exposed their devices to, after the implementation of a countermeasure or a feature. The goal of this research is to develop a characterization of power side channel attacks on different encryption algorithms\u27 implementations to create metrics and methods to evaluate their residual vulnerabilities and added vulnerabilities. This research studies the characteristics that influence the power side leakage, classifies them, and identifies both the residual vulnerabilities and the added vulnerabilities. Residual vulnerabilities are defined as the traits that leave the implementation of the algorithm still vulnerable to power Side Channel Attacks (SCA), sometimes despite the attempt at implementing countermeasures by the designers. Added vulnerabilities to power SCA are defined as vulnerabilities created or enhanced by the algorithm implementations and/or modifications. The three buckets in which we categorize the encryption algorithm implementations are: i. Countermeasures against power side channel attacks, ii. IC power delivery network impact to power leakage (including voltage regulators), iii. Lightweight ciphers and applications for the Internet of Things (IoT ) From the characterization of masking countermeasures, an example outcome developed is that masking schemes, when uniformly distributed random masks are used, are still vulnerable to collision power attacks. Another example outcome derived is that masked AES, when glitches occur, is still vulnerable to Differential Power Analysis (DPA). We have developed a characterization of power side-channel attacks on the hardware implementations of different symmetric encryption algorithms to provide a detailed analysis of the effectiveness of state-of-the-art countermeasures against local and remote power side-channel attacks. The characterization is accomplished by studying the attributes that influence power side-channel leaks, classifying them, and identifying both residual vulnerabilities and added vulnerabilities. The evaluated countermeasures include masking, hiding, and power delivery network scrambling. But, vulnerability to DPA depends largely on the quality of the leaked power, which is impacted by the characteristics of the device power delivery network. Countermeasures and deterrents to power side-channel attacks targeting the alteration or scrambling of the power delivery network have been shown to be effective against local attacks where the malicious agent has physical access to the target system. However, remote attacks that capture the leaked information from within the IC power grid are shown herein to be nonetheless effective at uncovering the secret key in the presence of these countermeasures/deterrents. Theoretical studies and experimental analysis are carried out to define and quantify the impact of integrated voltage regulators, voltage noise injection, and integration of on-package decoupling capacitors for both remote and local attacks. An outcome yielded by the studies is that the use of an integrated voltage regulator as a countermeasure is effective for a local attack. However, remote attacks are still effective and hence break the integrated voltage regulator countermeasure. From experimental analysis, it is observed that within the range of designs\u27 practical values, the adoption of on-package decoupling capacitors provides only a 1.3x increase in the minimum number of traces required to discover the secret key. However, the injection of noise in the IC power delivery network yields a 37x increase in the minimum number of traces to discover. Thus, increasing the number of on-package decoupling capacitors or the impedance between the local probing site and the IC power grid should not be relied on as countermeasures to power side-channel attacks, for remote attack schemes. Noise injection should be considered as it is more effective at scrambling the leaked signal to eliminate sensitive identifying information. However, the analysis and experiments carried out herein are applied to regular symmetric ciphers which are not suitable for protecting Internet of Things (IoT) devices. The protection of communications between IoT devices is of great concern because the information exchanged contains vital sensitive data. Malicious agents seek to exploit those data to extract secret information about the owners or the system. Power side channel attacks are of great concern on these devices because their power consumption unintentionally leaks information correlatable to the device\u27s secret data. Several studies have demonstrated the effectiveness of authenticated encryption with advanced data (AEAD), in protecting communications with these devices. In this research, we have proposed a comprehensive evaluation of the ten algorithm finalists of the National Institute of Standards and Technology (NIST) IoT lightweight cipher competition. The study shows that, nonetheless, some still present some residual vulnerabilities to power side channel attacks (SCA). For five ciphers, we propose an attack methodology as well as the leakage function needed to perform correlation power analysis (CPA). We assert that Ascon, Sparkle, and PHOTON-Beetle security vulnerability can generally be assessed with the security assumptions Chosen ciphertext attack and leakage in encryption only, with nonce-misuse resilience adversary (CCAmL1) and Chosen ciphertext attack and leakage in encryption only with nonce-respecting adversary (CCAL1) , respectively. However, the security vulnerability of GIFT-COFB, Grain, Romulus, and TinyJambu can be evaluated more straightforwardly with publicly available leakage models and solvers. They can also be assessed simply by increasing the number of traces collected to launch the attack

DFA on LS-Designs with a Practical Implementation on SCREAM (extended version)

LS-Designs are a family of SPN-based block ciphers whose linear layer is based on the so-called interleaved construction. They will be dedicated to low-end devices with high performance and low-resource constraints, objects which need to be resistant to physical attacks. In this paper we describe a complete Differential Fault Analysis against LS-Designs and also on other families of SPN-based block ciphers. First we explain how fault attacks can be used against their implementations depending on fault models. Then, we validate the DFA in a practical example on a hardware implementation of SCREAM running on an FPGA. The faults have been injected using electromagnetic pulses during the execution of SCREAM and the faulty ciphertexts have been used to recover the key’s bits. Finally, we discuss some countermeasures that could be used to thwart such attacks

A Survey of Lightweight Cryptosystems for Smart Home Devices

A Smart Home uses interconnected network technology to monitor the environment, control the various physical appliances, and communicate with each other in a close environment. A typical smart home is made up of a security system, intercommunication system, lighting system, and ventilation system.  Data security schemes for smart homes are ineffective due to inefficiency cryptosystems, high energy consumption, and low exchange security. Traditional cryptosystems are less-applicable because of their large block size, large key size, and complex rounds. This paper conducts a review of smart homes, and adopts Ultra-Sooner Lightweight Cryptography to secure home door. It provides extensive background of cryptography, forms of cryptography as associated issues and strengths, current trends, smart home door system design, and future works suggestions. Specifically, there are prospects of utilizing XORed lightweight cryptosystem for developing encryption and decryption algorithms in smart home devices. The Substitution Permutation Network, and Feistel Network cryptographic primitives were most advanced forms of cipher operations with security guarantees. Therefore, better security, memory and energy efficiency can be obtained with lightweight ciphers in smart home devices when compared to existing solutions. In the subsequent studies, a blockchain-based lightweight cryptography can be the next springboard in attaining the most advanced security for smart home systems and their appliances.     &nbsp

Face-off between the CAESAR Lightweight Finalists: ACORN vs. Ascon

Authenticated ciphers potentially provide resource savings and security improvements over the joint use of secret-key ciphers and message authentication codes. The CAESAR competition has aimed to choose the most suitable authenticated ciphers for several categories of applications, including a lightweight use case, for which the primary criteria are performance in resource-constrained devices, and ease of protection against side channel attacks (SCA). In March 2018, two of the candidates from this category, ACORN and Ascon, were selected as CAESAR contest finalists. In this research, we compare two SCA-resistant FPGA implementations of ACORN and Ascon, where one set of implementations has area consumption nearly equivalent to the defacto standard AES-GCM, and the other set has throughput (TP) close to that of AES-GCM. The results show that protected implementations of ACORN and Ascon, with area consumption less than but close to AES-GCM, have 23.3 and 2.5 times, respectively, the TP of AES-GCM. Likewise, implementations of ACORN and Ascon with TP greater than but close to AES-GCM, consume 18 percent and 74 percent of the area, respectively, of AES-GCM

A First DFA on PRIDE: from Theory to Practice (extended version)

PRIDE is one of the most effcient lightweight block cipher proposed so far for connected objects with high performance and low resource constraints. In this paper we describe the first ever complete Differential Fault Analysis against PRIDE. We describe how fault attacks can be used against implementations of PRIDE to recover the entire encryption key. Our attack has been validated first through simulations, and then in practice on a software implementation of PRIDE running on a device that could typically be used in IoT devices. Faults have been injected using electromagnetic pulses during the PRIDE execution and the faulty ciphertexts have been used to recover the key bits. We also discuss some countermeasures that could be used to thwart such attacks

Side Channel Attacks: Vulnerability Analysis of PRINCE and RECTANGLE using DPA

Over a decade, cryptographers are more attentive on designing lightweight ciphers in focus to compact cryptographic devices. More often, the security of these algorithms are defined in terms of its resistance to mathematical cryptanalysis methods. Nevertheless, designers are well aware of implementation attacks and concentrating on new design strategies to improve the defence quality against implementation attack. PRINCE ~\cite{Julia2012} and RECTANGLE ~\cite{cryptoeprint:2014:084} lightweight block ciphers are designed using new design strategies for efficiency and security. In this paper we analyse the security of PRINCE and RECTANGLE against a type of implementation attack called Differential Power Analysis (DPA) attack. Our attack reduces key search space from $2^{128}$ to $33008$ for PRINCE and $2^{80}$ to $288$ for RECTANGLE