Periodic Reporting for period 2 - SWORD (Security Without Obscurity for Reliable Devices)
Reporting period: 2019-03-01 to 2020-08-31
Overall, the projects’ achievements are in four directions: mathematical aspects: primitives & definitions, physical assumptions, open source hardware and software and evaluation & verification. Strong achievements have been obtained in all directions, as suggested by the list of papers published. In summary, the main advances can be described as follows:
For the mathematical aspects, strong efforts have been paid towards understanding security definitions for leakage-resistant authenticated encryption and designs that can satisfy this definition. Our team also invested significant time in extending the formal analysis of masking schemes (in terms of composability and resistance against physical defaults).
The understanding of the noise and independence assumptions that are required for algorithmic countermeasures such as masking to deliver security were at the core of our investigation regarding physical assumptions, together with the analysis of new learning problems (in particular the Learning Parity with Physical Noise problem).
Most of our ideas were tested based on open prototype implementations. This includes software (e.g. ARM Cortex) and FPGA implementations, but also the tape out of a chip that we plan to analyze in the coming months in terms of the leakage noise it provides.
Finally, the sound evaluation of physical security remains an important challenge. Major steps have been obtained in order to enable strict bounds for the information leakage of an implementation (and several other results to pinpoint limitations in other approaches).
Most importantly, we intend to combine these advances in complete solutions for side-channel resistant authenticated encryption. One part of this result is the Spook proposal (https://www.spook.dev/) that has been submitted to the NIST Lightweight Cryptography competition. Based on this (and possibly other) algorithm, we plan to develop leveled implementations that we will make available to public audits via cryptanalysis challenges.