A first step towards automatic application of power analysis countermeasures

Abstract

In cryptography, side channel attacks, such as power analysis, attempt to uncover secret information from the physical implementation of cryptosystems rather than exploiting weaknesses in the cryptographic algorithms themselves. The design and implementation of physically secure cryptosystems is a challenge for both hardware and software designers. Measuring and evaluating the security of a system is manual and empirical, which is costly and time consuming; this work demonstrates that it is possible to automate these processes. We introduce a systematic methodology for automatic application of software countermeasures and demonstrate its effectiveness on an AES software implementation running on an 8-bit AVR microcontroller. The framework identifies the most vulnerable instructions of the implementation to power analysis attacks, and then transforms the software using a chosen countermeasure to protect the vulnerable instructions. Lastly, it evaluates the security of the system using an information-theoretic metric and a direct attack.

A Novel Design Flow for a Security-Driven Synthesis of Side-Channel Hardened Cryptographic Modules

“…[17]. Such a late consideration is especially disadvantageous as it forces the designer to rerun the overall design process in order to include side-channel countermeasures.…”

“…Countermeasures against side-channel attacks in software implementations of crypto modules are in the focus of three approaches, which provide automated code analysis and countermeasure integration, cf. [17,[22][23][24]. The work in [17] applies a side-channel attack to the assembled code and utilizes an estimation of the mutual information [18] to evaluate and to highlight vulnerabilities of a specific code section.…”

“…[17,[22][23][24]. The work in [17] applies a side-channel attack to the assembled code and utilizes an estimation of the mutual information [18] to evaluate and to highlight vulnerabilities of a specific code section. The second method, proposed by Moss et al in [22,23], features an automatic insertion of masks by evaluating the secrecy requirements of an intermediate value in the program code.…”

“…The exchange of vulnerable net-list elements is based on an evaluation aimed at identifying security-sensitive parts, which need to be hardened by means of this specific logic style. Recently, Bayrak et al extended the framework introduced in [17], see [25]. In addition to random precharching, they introduced Boolean masking as an advanced countermeasure, which assumes a global code transformation.…”

“…In fact, the designer has to anticipate which attacks a potential adversary will conduct on her or his design. The proposal in [17] overcomes this problem by utilizing an estimation of the mutual information as a side-channel distinguisher.…”