Mgr. Tomáš Rabas

Článek

10.1007/s42979-023-02493-7

Katedra informační bezpečnosti

Most of the currently used cryptosystems are not secure in the presence of cryptographically relevant quantum computers. As the research in quantum technologies proceeds, a need for quantum-safe cryptography is imminent. NTRU is a post-quantum public-key cryptosystem based on lattices and was a finalist in the 3rd round of the post-quantum standardization process organized by the National Institute of Standards and Technology (NIST). This paper aims to study the implementation security of the cryptosystem with respect to an attacker with access to power leakage. Such a threat model is relevant especially, but not only, for embedded devices. We studied a countermeasure implementation of the NTRU decryption algorithm from An et al. (Appl Sci https://doi.org/10.3390/app8112014 , 2018) that claimed its security against power attacks. This paper revisits an attack presented in as reported by Rabas (In: Proceedings of the9th International Conference on Information Systems Security and Privacy,ICISSP 2023, Lisbon, 2023) that shows it is in fact vulnerable even in the case of just a single trace available to the enemy for extracting the key. We then describe a new profiling template attack on the implementation and show experimental results of the attack using the same datasets, resulting in a comparison of these two methods and further confirmation of the vulnerability of the algorithm even to generic profiling attacks. Several possible types of countermeasures are discussed.

Stať ve sborníku

10.1109/DSD60849.2023.00027

Katedra informační bezpečnosti

NTRU is a post-quantum public key cryptosystem based on lattices and was a finalist in the 3rd round of the post-quantum standardization process organized by the National Institute of Standards and Technology (NIST). We present a new single-trace attack against the NTRU decryption algorithm, meaning we can obtain the private key only from one power trace, assuming the profiling phase was conducted before the attack. The attack was performed on the submission implementation from the standardization process. We used several machine learning methods and Template attacks for the profiling and testing phase. Both methods achieve high accuracy reaching almost 100% tested on more than 12 000 traces. We also provide a comparison of their success score with regard to a different number of points of interest

Stať ve sborníku

10.5220/0011729200003405

Katedra informační bezpečnosti

NTRU is a post-quantum public-key, lattice-based cryptosystem. Several suggested implementations claim to be simple-power analysis resistant. One of these implementations was described in (An et al., 2018) using a sparse representation of a private key and a new design of an algorithm for the multiplication of polynomials. We show that it is still vulnerable. We theoretically explain a vulnerability in the algorithm description that could potentially lead to a single-trace attack. We practically perform the attack on two targets with different architectures: an 8-bit microcontroller of the AVR family and a 32-bit microcontroller ARM Cortex-M0. Statistical analysis performed on the second target, measured by the ChipWhisperer platform, shows that with a chance of 91.0% we get the correct key just from one measured trace. Ability to get two measurements raises our probability of a successful attack up to 99.6%.

Stať ve sborníku

10.5220/0011299000003283

Katedra informační bezpečnosti

Paper from 2020 (Buchovecká et al., 2020) suggests protocols suitable for lightweight IoT Devices. They are based on physical unclonable functions (PUF) which among others simplify the problem of key management on simple hardware devices and microcontrollers. These protocols are supposed to authenticate a device and distribute keys safely so that only the intended parties can know the key. We analysed suggested protocols using two automated verification tools AVISPA and Scyther. The analysis shows that there are several issues concerning the authentication property. We demonstrate the results from the tools and describe several attacks that exploit this vulnerability. Finally, we provide modified versions of these protocols that are resistant to those attacks and satisfy authentication as desired.