Single-trace clustering power analysis of the point-swapping procedure in the three point ladder of Cortex-M4 SIKE

In this paper, the recommended implementation of the post-quantum key exchange SIKE for Cortex-M4 is attacked through power analysis with a single trace by clustering with the $k$-means algorithm the power samples of all the invocations of the elliptic curve point swapping function in the constant-time coordinate-randomized three point ladder. Because each sample depends on whether two consecutive bits of the private key are the same or not, a successful clustering (with $k=2$) leads to the recovery of the entire private key. The attack is naturally improved with better strategies, such as clustering the samples in the frequency domain or processing the traces with a wavelet transform, using a simpler clustering algorithm based on thresholding, and using metrics to prioritize certain keys for key validation. The attack and the proposed improvements were experimentally verified using the ChipWhisperer framework. Splitting the swapping mask into multiple shares is suggested as an effective countermeasure

Improving the Performance of Scala Collections with Miniboxing

Using generics, Scala collections can be used to store different types of data in a type-safe manner. Unfortunately, due to the erasure transformation, the performance of generics is degraded when storing primitive types, such as integers and floating point numbers. Miniboxing is a novel translation for generics that restores primitive type performance. Naturally, a good choice would be to use miniboxing to translate Scala collections. In this paper we explore the patterns used to implement the Scala collections, describe how they are transformed by miniboxing and finally compare the performance of the two transformations on a mockup of the Scala collection library. The benchmarks show our prototype implementation (http://scala-miniboxing.org) can speed up collection operations by 45% without any need for programmer intervention

Practical Fault Injection Attacks on SPHINCS

The majority of currently deployed cryptographic public-key schemes are at risk of becoming insecure once large scale quantum computers become practical. Therefore, substitutes resistant to quantum attacks楊nown as post-quantum cryptography預re required. In particular, hash-based signature schemes appear to be the most conservative choice for post-quantum digital signatures. In this work, we mount the first practical fault attack against hash-based cryptography. The attack was originally proposed by Castelnovi, Martinelli, and Prest [9] and allows the creation of a universal signature forgery that applies to all current standardisation candidates (XMSS, LMS, SPHINCS+, and Gravity-SPHINCS). We perform the attack on an Arduino Due board featuring an ARM Cortex-M3 microprocessor running the original stateless scheme SPHINCS with a focus on practicality. We describe how the attack is mountable with a simple voltage glitch injection on the targeted platform, which allowed us to collect enough faulty signatures to create a universal forgery within seconds. As the attack also applies to stateful schemes, we show how caching one-time signatures can entirely prevent the attack for stateful schemes, such as XMSS and LMS. However, we discuss how protecting stateless schemes, like SPHINCS, SPHINCS+, and Gravity-SPHINCS, is more challenging, as this countermeasure does not apply as efficiently as in stateful schemes

SIKE Channels

We present new side-channel attacks on SIKE, the isogeny-based candidate in the NIST PQC competition. Previous works had shown that SIKE is vulnerable to differential power analysis and pointed to coordinate randomization as an effective countermeasure. We show that coordinate randomization alone is not sufficient, as SIKE is vulnerable to a class of attacks similar to refined power analysis in elliptic curve cryptography, named zero-value attacks. We describe and confirm in the lab two such attacks leading to full key recovery, and analyze their countermeasures

On Protecting SPHINCS+ Against Fault Attacks

SPHINCS+ is a hash-based digital signature scheme that was selected by NIST in their post-quantum cryptography standardization process. The establishment of a universal forgery on the seminal scheme SPHINCS was shown to be feasible in practice by injecting a fault when the signing device constructs any non-top subtree. Ever since the attack has been made public, little effort was spent to protect the SPHINCS family against attacks by faults. This paper works in this direction in the context of SPHINCS+ and analyzes the current algorithms that aim to prevent fault-based forgeries.First, the paper adapts the original attack to SPHINCS+ reinforced with randomized signing and extends the applicability of the attack to any combination of faulty and valid signatures. Considering the adaptation, the paper then presents a thorough analysis of the attack. In particular, the analysis shows that, with high probability, the security guarantees of SPHINCS+ significantly drop when a single random bit flip occurs anywhere in the signing procedure and that the resulting faulty signature cannot be detected with the verification procedure. The paper shows both in theory and experimentally that the countermeasures based on caching the intermediate W-OTS+s offer a marginally greater protection against unintentional faults, and that such countermeasures are circumvented with a tolerable number of queries in an active attack. Based on these results, the paper recommends real-world deployments of SPHINCS+ to implement redundancy checks

SIKE Channels: Zero-Value Side-Channel Attacks on SIKE

We present new side-channel attacks on SIKE, the isogeny-based candidate in the NIST PQC competition. Previous works had shown that SIKE is vulnerable to differential power analysis, and pointed to coordinate randomization as an effective countermeasure. We show that coordinate randomization alone is not sufficient, because SIKE is vulnerable to a class of attacks similar to refined power analysis in elliptic curve cryptography, named zero-value attacks. We describe and confirm in the lab two such attacks leading to full key recovery, and analyze their countermeasures