Mechanized proofs that hardware is safe from timing attacks

A recurring problem in cryptography engineering is the potential for secret data to be leaked through aspects of software and hardware that are orthogonal to functional correctness. In particular, much effort is put into writing cryptography code whose timing behavior - how many CPU clock cycles it takes to complete a given cryptographic operation - is independent of any secret inputs to that operation. This is a difficult problem because it depends not only on the code itself, but also on various optimizations such as branch prediction and memory caching implemented by the underlying hardware the program runs on. We make use of Kami, a domain-specific language for describing and formally verifying hardware modules, to build a system for constructing machine-checked proofs that a given piece of code running on a given RISC-V CPU design will not leak secret inputs through timing behavior. Our system allows software and hardware to be analyzed and verified independently, and we prove that any combination of software and hardware that meet our validation criteria will be safe from timing-based side channels. We demonstrate an example of validating a real cryptographic program and a concrete RISC-V CPU using our system, illustrating the applicability of our tools and laying the groundwork for validating more complex programs and CPUs.

Name thesis:degree_name

Master

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2018

Author dc:creator

• Duxovni, Faye(Faye Samara)

Advisor dc:contributor.advisor

• Adam Chlipala.

• Electrical Engineering and Computer Science.

Statement dc:rights

• MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

https://hdl.handle.net/1721.1/122053

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/122053