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An Improved Recovery Algorithm for Decayed AES Key Schedule Images

  • Alex Tsow
Part of the Lecture Notes in Computer Science book series (LNCS, volume 5867)

Abstract

A practical algorithm that recovers AES key schedules from decayed memory images is presented. Halderman et al. [1] established this recovery capability, dubbed the cold-boot attack, as a serious vulnerability for several widespread software-based encryption packages. Our algorithm recovers AES-128 key schedules tens of millions of times faster than the original proof-of-concept release. In practice, it enables reliable recovery of key schedules at 70% decay, well over twice the decay capacity of previous methods. The algorithm is generalized to AES-256 and is empirically shown to recover 256-bit key schedules that have suffered 65% decay. When solutions are unique, the algorithm efficiently validates this property and outputs the solution for memory images decayed up to 60%.

Keywords

anti-tamper digital forensics decayed memory cold-boot attack AES key schedule 

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Copyright information

© Springer-Verlag Berlin Heidelberg 2009

Authors and Affiliations

  • Alex Tsow
    • 1
  1. 1.The MITRE Corporation 

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