| Title | Securing AES against Localized EM Attacks through Spatial Randomization of Dataflow |
| Publication Type | Conference Paper |
| Year of Publication | 2019 |
| Authors | Li, Ge, Iyer, Vishnuvardhan, Orshansky, Michael |
| Conference Name | 2019 IEEE International Symposium on Hardware Oriented Security and Trust (HOST) |
| Keywords | AES, black box encryption, black-box model attack, composability, countermeasures, cryptography, dataflow, datapath components, dynamic random mapping, embedded cryptographic implementations, Encryption, exploitable leakage, fixed S-box, fully controlled access, generic attack, high resolution EM probes, high-performance implementation, information leakage, localized electromagnetic attack, localized EM attacks, Metrics, minimum traces to disclosure, permutation network, potent threat, Power Attacks, Probes, profiled attack, pubcrawl, randomization results, Registers, resilience, Resiliency, Semiconductor device measurement, sensitive data, side-channel attacks, spatial randomization, state register byte, transient random value |
| Abstract | A localized electromagnetic (EM) attack is a potent threat to security of embedded cryptographic implementations. The attack utilizes high resolution EM probes to localize and exploit information leakage in sub-circuits of a system, providing information not available in traditional EM and power attacks. In this paper, we propose a countermeasure based on randomizing the assignment of sensitive data to parallel datapath components in a high-performance implementation of AES. In contrast to a conventional design where each state register byte is routed to a fixed S-box, a permutation network, controlled by a transient random value, creates a dynamic random mapping between the state registers and the set of S-boxes. This randomization results in a significant reduction of exploitable leakage.We demonstrate the countermeasure's effectiveness under two attack scenarios: a more powerful attack that assumes a fully controlled access to an attacked implementation for building a priori EM-profiles, and a generic attack based on the black-box model. Spatial randomization leads to a 150x increase of the minimum traces to disclosure (MTD) for the profiled attack and a 3.25x increase of MTD for the black-box model attack. |
| DOI | 10.1109/HST.2019.8741026 |
| Citation Key | li_securing_2019 |
Securing AES against Localized EM Attacks through Spatial Randomization of Dataflow