Ruhr-Universität Bochum (RUB): Open Journal Systems
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Chameleon: A Dataset for Segmenting and Attacking Obfuscated Power Traces in Side-Channel Analysis
Get PDFSide-channel attacks exploit unintended information leakage emitted by cryptographic devices to extract sensitive data. Hiding techniques are a cost-effective countermeasure designed to obfuscate the side-channel leakage and hinder these attacks. Available open datasets rely on artificial models to simulate hiding effects, preventing a realistic assessment of these countermeasures and, thus, leaving a pressing need for datasets offering real-world, obfuscated side-channel measurements. Chameleon introduces the first comprehensive dataset of real-world, obfuscated power traces collected from a RISC-V-based System-on-Chip. The traces are obfuscated using four state-of-the-art hiding techniques: dynamic frequency scaling, random delay, morphing, and chaffing. Chameleon captures real leakage deformations introduced by actual hardware implementations, making it a realistic and valuable tool for evaluating side-channel countermeasures. A key feature of Chameleon is its dual focus on the segmentation and attack stages of the side-channel analysis process. It is the first dataset designed to facilitate the challenging task of segmenting cryptographic operations from obfuscated traces, offering precise metadata that pinpoints the start and end of each operation. The high-quality metadata enables systematic research into segmentation techniques, a critical step often overlooked in previous datasets. Chameleon provides an essential platform for researchers to develop and test new side-channel attacks, highlighting the vulnerabilities of current hiding techniques. By offering a more realistic assessment of countermeasure effectiveness, Chameleon is an invaluable tool for advancing the state-of-the-art in the side-channel evaluation
HRaccoon: A High-performance Configurable SCA Resilient Raccoon Hardware Accelerator
Get PDFThe lattice-based Raccoon scheme is one of the candidates in Round 1 of the National Institute of Standards and Technology (NIST) post-quantum cryptography (PQC) additional digital signatures standardization process. As a scheme with built-in masking features, Raccoon is also a viable candidate for NIST’s Masking Circuit and Threshold Cryptography project. Current Raccoon implementations are limited to software or software-hardware co-designs only and consequently lacking in terms of high throughput performance that hardware implementations can generally promise. To achieve this, we are the first to propose a configurable and high-performance pure hardware architecture for Raccoon. The proposed FPGA architecture features extensive optimizations in key modules for Raccoon such as the modular reduction, polynomial operations, and sampling. The segmentation and loop-based scheduling scheme interacts with the defined BRAM-based memory access pattern to ensure efficient and coherent data flow under the three security levels and two masking modes (non- and first-order masking). Implementation results of Raccoon on an AMD Artix- 7 FPGA device show that our proposed architecture achieves a 1.4–2.1x speedup compared to software implementations and a 20–42x speedup compared to softwarehardware co-designs for the three security levels, despite its hardware area being comparable to that of the lightweight CRYSTALS-Dilithium architecture. Finally, a TVLA test is demonstrated on Raccoon-128 with non-masking and first-order masking to evaluate its resilience to side-channel attacks
Rethinking Symbolic Violence on Social Media: Incels and Mentalisation
Get PDFThe aim of this article is to discuss the notion of symbolic violence and to foreground a psychoanalytic conceptualisation of the term. Having been popularised by Pierre Bourdieu and other thinkers, the term is routinely used to describe forms of violence that stop short of the physical. It remains under-theorised. Following a brief literature review, it is argued that psychoanalysis has much to add when it comes to conceptualising symbolic violence and how it plays out online. Peter Fonagy’s theory of mentalisation is brought in to conceptualise symbolic violence as a particular form of externalised, distorted mentalisation. I finally apply the term to contemporary discussions and user exchanges on social media that are so often characterised by intense forms of symbolic violence. The misogynist incel community is presented as a case study via exemplary quotes. Incels display forms of symbolic violence that are characterised by vivid fantasies about other men and women which reveal a distorted, yet highly coherent and organised, symbolic world.
Time travel to better futures: A pilot project for transformative learning in a tandem course
Get PDFDer Beitrag erweitert die Perspektive auf Nachhaltigkeit und Bildung für nachhaltige Entwicklung (BNE) durch die Einführung des Konzepts der Regeneration beim Fremdsprachenlernen. Er führt mit transformativen Lernprozessen mit dem Fokus auf (kollektive) Zukunftsvisionen eine Möglichkeit ein, wie Handlungsfähigkeit und Resilienz gestärkt werden können. Dabei wird der Einfluss von Sprache und Kultur auf unser Denken und Handeln hervorgehoben.
Ein Pilotprojekt in einem Tandemkurs reflektiert die praktische Anwendung. Abschließend werden konkrete Impulse und Empfehlungen für die Einbindung dieses Ansatzes in die Unterrichtspraxis gegeben.The article broadens the perspective on sustainability and education for sustainable development (ESD) by introducing the concept of regeneration in foreign language learning. It introduces transformative learning processes focussing on (collective) visions of the future as a way of strengthening agency and resilience. It emphasises the influence of language and culture on our thoughts and actions.
A pilot project in a tandem course reflects the practical application. Finally, concrete impulses and recommendations for the integration of this approach into teaching practice are given
ECTester: Reverse-engineering side-channel countermeasures of ECC implementations
No full textDevelopers implementing elliptic curve cryptography (ECC) face a wide range of implementation choices created by decades of research into elliptic curves. The literature on elliptic curves offers a plethora of curve models, scalar multipliers, and addition formulas, but this comes with the price of enabling attacks to also use the rich structure of these techniques. Navigating through this area is not an easy task and developers often obscure their choices, especially in black-box hardware implementations. Since side-channel attackers rely on the knowledge of the implementation details, reverse engineering becomes a crucial part of attacks.This work presents ECTester – a tool for testing black-box ECC implementations. Through various test suites, ECTester observes the behavior of the target implementation against known attacks but also non-standard inputs and elliptic curve parameters. We analyze popular ECC libraries and smartcards and show that some libraries and most smartcards do not check the order of the input points and improperly handle the infinity point. Based on these observations, we design new techniques for reverse engineering scalar randomization countermeasures that are able to distinguish between group scalar randomization, additive, multiplicative or Euclidean splitting. Our techniques do not require side-channel measurements; they only require the ability to set custom domain parameters, and are able to extract not only the size but also the exact value of the random mask used. Using the techniques, we successfully reverse-engineered the countermeasures on 13 cryptographic smartcards from 5 major manufacturers – all but one we tested on. Finally, we discuss what mitigations can be applied to prevent such reverse engineering, and whether it is possible at all
Sharing the Mask: TFHE Bootstrapping on Packed Messages
No full textFully Homomorphic Encryption (FHE) schemes typically experience significant data expansion during encryption, leading to increased computational costs and memory demands during homomorphic evaluations compared to their plaintext counterparts. This work builds upon prior methods aimed at reducing ciphertext expansion by leveraging matrix secrets under the Matrix-LWE assumption. In particular, we consider a ciphertext format referred to in this work as common mask (CM) ciphertexts, which comprises a shared mask and multiple message bodies. Each body encrypts a distinct message while reusing the common random mask. We demonstrate that all known FHEW/TFHE-style ciphertext variants and operations can be naturally extended to this CM format. Our benchmarks highlight the potential for amortizing operations using the CM structure, significantly reducing overhead. For instance, in the boolean setting, we have up to a 51% improvement when packing 8 messages. Beyond ciphertext compression and amortized evaluations, the CM format also enables the generalization of several core-TFHE operations. Specifically, we support applying distinct lookup tables on different encrypted messages within a single CM ciphertext and private linear operations on messages encrypted within the same CM ciphertext
Probing Secure Composability Without Fresh Randomness: Theory and Application to Ascon
No full textSide-channel attacks (SCAs) pose a significant threat to the implementations of lightweight ciphers, particularly in resource-constrained environments where masking—the primary countermeasure—is constrained by tight resource limitations. This makes it crucial to reduce the resource and randomness requirements of masking schemes. In this work, we investigate an approach to minimize the randomness complexity of masking algorithms. Specifically, we explore the theoretical foundations of higher-order masking schemes that eliminate the need for online (fresh) randomness by relying solely on offline randomness present in the initial input shares.We demonstrate that round-based ciphers with linear diffusion layers can support such deterministic composition, where the diffusion layer acts as a refresh subcircuit. This ensures that, up to a threshold number, probes placed across rounds remain independent. Based on this observation, we propose composition theorems for probing-secure masking. On the practical side, we instantiate our framework using known deterministic first- and second-order masked S-boxes and provide software implementations of Ascon’s protected permutation