Voltage glitching is one of the most prominent fault injection techniques due to its effectiveness and simplicity. Although it is generally regarded as a spatially global fault method, in which the injected glitch uniformly affects all circuits on the die, several studies have observed that specific locations may be affected more than others. To characterize this phenomenon, we draw inspiration from methods used in electromagnetic interference (EMI) analysis. In this paper, we demonstrate...

Ransomware remains a persistent cybersecurity threat difficult to detect due to high-dimensional network traffic and sophisticated obfuscation techniques. Existing feature selection methods often struggle with redundancy, noise, and the curse of dimensionality, leading to poor generalisation and limited interpretability in ransomware detection. To address these challenges, we propose BioSparse-MCP, a hybrid feature selection framework that integrates gradient-based optimisation with the...

Searchable Encryption (SE) has shown a lot of promise towards enabling secure and efficient queries over encrypted data. In order to achieve this efficiency, SE inevitably leaks some information, and a big open question is how dangerous this leakage is. While prior reconstruction attacks have demonstrated effectiveness in one-dimensional settings, extending them to high-dimensional datasets remains challenging. Existing methods either demand excessive query information (e.g. an attacker that...

Electromagnetic side-channel analysis is a powerful method for monitoring processor activity and compromising cryptographic systems in air-gapped environments. As analytical methodologies and target devices evolve, the importance of leakage localization and probe aiming becomes increasingly apparent for capturing only the desired signals with a high signal-to-noise ratio. Despite its importance, there remains substantial reliance on unreliable heuristic approaches and inefficient exhaustive...

We show a general method of compiling any $k$-prover non-local game into a single-prover interactive game maintaining the same (quantum) completeness and (classical) soundness guarantees (up to negligible additive factors in a security parameter). Our compiler uses any quantum homomorphic encryption scheme (Mahadev, FOCS 2018; Brakerski, CRYPTO 2018) satisfying a natural form of correctness with respect to auxiliary (quantum) input. The homomorphic encryption scheme is used as a...

Practical side-channel attacks on recent devices may be challenging due to the poor quality of acquired signals. It can originate from different factors, such as the growing architecture complexity, especially in System-on-Chips, creating unpredictable and concurrent operation of multiple signal sources on the device. This work makes use of mixture distributions to formalize this complexity, allowing us to explain the benefit of using a technique like Scatter, where different samples of the...

With the location-based services (LBS) booming, the volume of spatial data inevitably explodes. In order to reduce local storage and computational overhead, users tend to outsource data and initiate queries to the cloud. However, sensitive data or queries may be compromised if cloud server has access to raw data and plaintext token. To cope with this problem, searchable encryption for geometric range is applied. Geometric range search has wide applications in many scenarios, especially the...

With the location-based services booming, the volume of spatial data inevitably explodes. In order to reduce local storage and computational overhead, users tend to outsource data and initiate queries to the cloud. However, sensitive data or queries may be compromised if cloud server has access to raw data and plaintext token. To cope with this problem, searchable encryption for geometric range is applied. Geometric range search has wide applications in many scenarios, especially the...

We describe SKIVA, a customized 32-bit processor enabling the design of software countermeasures for a broad range of implementation attacks covering fault injection and side-channel analysis of timing-based and power-based leakage. We design the countermeasures as variants of bitslice programming. Our protection scheme is flexible and modular, allowing us to combine higher-order masking -- fending off side-channel analysis -- with complementary spatial and temporal redundancy -- protecting...

Near-field microprobes have the capability to isolate small regions of a chip surface and enable precise measurements with high spatial resolution. Being able to distinguish the activity of small regions has given rise to the location-based sidechannel attacks, which exploit the spatial dependencies of cryptographic algorithms in order to recover the secret key. Given the fairly uncharted nature of such leakages, this work revisits the location side-channel to broaden our modeling and...

Achieving side-channel resistance through Leakage Resilience (LR) is highly relevant for embedded devices where requirements of other countermeasures such as e.g. high quality random numbers are hard to guarantee. The main challenge of LR lays in the initialization of a secret pseudorandom state from a long-term key and public input. Leakage-Resilient Pseudo-Random Functions (LR-PRFs) aim at solving this by bounding side-channel leakage to non-exploitable levels through frequent re-keying....

The device-unique response of a physically unclonable function (PUF) can serve as the root of trust in an embedded cryptographic system. Fuzzy extractors transform this noisy non-uniformly distributed secret into a stable high-entropy key. The overall efficiency thereof, typically depending on error-correction with a binary [n,k,d] block code, is determined by the universal and well-known (n-k) bound on the min-entropy loss. We derive new considerably tighter bounds for PUF-induced...

Classical fault attacks such as Differential Fault Analysis~(DFA) as well as biased fault attacks such as the Differential Fault Intensity Analysis~(DFIA) have been a major threat to cryptosystems in recent times. DFA uses pairs of fault-free and faulty ciphertexts to recover the secret key. DFIA, on the other hand, combines principles of side channel analysis and fault attacks to try and extract the key using faulty ciphertexts only. Till date, no effective countermeasure that can thwart...

State-of-the-art fault-based cryptanalysis methods are capable of breaking most recent ciphers after only a few fault injections. However, they require temporal and spatial accuracies of fault injection that were believed to rule out low-cost injection techniques such as voltage, frequency or temperature manipulation. We investigate selection of supply-voltage and temperature values that are suitable for high-precision fault injection even up to a single bit. The object of our studies is an...