FaultMeter: Quantitative Fault Attack Assessment of Block Cipher Software

Abstract

Fault attacks are a potent class of physical attacks that exploit a fault njected during device operation to steal secret keys from a cryptographic device. The success of a fault attack depends intricately on (a) the cryptographic properties of the cipher, (b) the program structure, and (c) the underlying hardware architecture. While there are several tools that automate the process of fault attack evaluation, none of them consider all three influencing aspects. This paper proposes a framework called FaultMeter that builds on the state-of-art by not just identifying fault vulnerable locations in a block cipher software, but also providing a quantification for each vulnerable location. The quantification provides a probability that an injected fault can be successfully exploited. It takes into consideration the cryptographic properties of the cipher, structure of the implementation, and the underlying Instruction Set Architecture’s (ISA) susceptibility to faults. We demonstrate an application of FaultMeter to automatically insert optimal amounts of countermeasures in a program to meet the user’s security requirements while minimizing overheads. We demonstrate the versatility of the FaultMeter framework by evaluating five cipher implementations on multiple hardware platforms, namely, ARM (32 and 64 bit), RISC-V (32 and 64 bit), TI MSP-430 (16-bit) and Intel x86 (64-bit).

Keywords

• Fault Attack
• Automatic Fault Attack Evaluation
• Quantification Countermeasures