Beyond-Birthday-Bound Security for 4-round Linear Substitution-Permutation Networks

Recent works of Cogliati et al. (CRYPTO 2018) have initiated provable treatments of Substitution-Permutation Networks (SPNs), one of the most popular approach to construct modern blockciphers. Such theoretical SPN models may employ non-linear diffusion layers, which enables beyond-birthday-bound provable security. Though, for the model of real world blockciphers, i.e., SPN models with linear diffusion layers, existing provable results are capped at birthday security up to 2n/2 adversarial queries, where n is the size of the idealized S-boxes.In this paper, we overcome this birthday barrier and prove that a 4-round SPN with linear diffusion layers and independent round keys is secure up to 22n/3 queries. For this, we identify conditions on the linear layers that are sufficient for such security, which, unsurprisingly, turns out to be slightly stronger than Cogliati et al.’s conditions for birthday security. These provides additional theoretic supports for real world SPN blockciphers.

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A NOVEL IMAGE ENCRYPTION BASED ON ROSSLER MAP DIFFUSION AND PARTICLE SWARM OPTIMIZATION GENERATED HIGHLY NON-LINEAR SUBSTITUTION BOXES

Chinese Journal of Physics ◽

10.1016/j.cjph.2021.03.029 ◽

2021 ◽

Author(s):

Lal Said Khan ◽

Mohammad Mazyad Hazzazi ◽

Majid Khan ◽

Sajjad Shaukat Jamal

Keyword(s):

Particle Swarm Optimization ◽

Image Encryption ◽

Particle Swarm ◽

Swarm Optimization ◽

Linear Substitution ◽

Substitution Boxes ◽

Non Linear

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A Rapid Non-Linear Diffusion Compressed Sensing parallel MR Image Reconstruction

Proceedings of the 11th Indian Conference on Computer Vision, Graphics and Image Processing ◽

10.1145/3293353.3293411 ◽

2018 ◽

Author(s):

Ajin Joy ◽

Joseph Suresh Paul

Keyword(s):

Image Reconstruction ◽

Compressed Sensing ◽

Mr Image ◽

Linear Diffusion ◽

Non Linear ◽

Mr Image Reconstruction

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A secure and highly efficient first-order masking scheme for AES linear operations

Cybersecurity ◽

10.1186/s42400-021-00082-w ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Jingdian Ming ◽

Yongbin Zhou ◽

Huizhong Li ◽

Qian Zhang

Keyword(s):

Cost Reduction ◽

Provable Security ◽

State Of The Art ◽

Side Channel ◽

First Order ◽

Highly Efficient ◽

Non Linear ◽

Device Independence ◽

Practical Implications ◽

Provably Secure

AbstractDue to its provable security and remarkable device-independence, masking has been widely accepted as a noteworthy algorithmic-level countermeasure against side-channel attacks. However, relatively high cost of masking severely limits its applicability. Considering the high tackling complexity of non-linear operations, most masked AES implementations focus on the security and cost reduction of masked S-boxes. In this paper, we focus on linear operations, which seems to be underestimated, on the contrary. Specifically, we discover some security flaws and redundant processes in popular first-order masked AES linear operations, and pinpoint the underlying root causes. Then we propose a provably secure and highly efficient masking scheme for AES linear operations. In order to show its practical implications, we replace the linear operations of state-of-the-art first-order AES masking schemes with our proposal, while keeping their original non-linear operations unchanged. We implement four newly combined masking schemes on an Intel Core i7-4790 CPU, and the results show they are roughly 20% faster than those original ones. Then we select one masked implementation named RSMv2 due to its popularity, and investigate its security and efficiency on an AVR ATMega163 processor and four different FPGA devices. The results show that no exploitable first-order side-channel leakages are detected. Moreover, compared with original masked AES implementations, our combined approach is nearly 25% faster on the AVR processor, and at least 70% more efficient on four FPGA devices.

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