Paper 2018/614

A Note on Key Rank

Daniel P. Martin and Marco Martinoli


In recent years key rank has become an important aspect of side-channel analysis, enabling an evaluation lab to analyse the security of a device after a side-channel attack. In particular, it enables the lab to do so when the enumeration effort would be beyond their computing power. Due to its importance there has been a host of work investigating key rank over the last few years. In this work we build upon the existing literature to make progress on understanding various properties of key rank. We begin by showing when two different "scoring methods" will provide the same rank. This has been implicitly used by various algorithms in the past but here it is shown for a large class of functions. We conclude by giving the computational complexity of key rank. This implies that it is unlikely for, considerably, better algorithms to exist.

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Publication info
Preprint. MINOR revision.
Side-channel AttacksKey RankScoring Methods
Contact author(s)
dan martin @ bristol ac uk
2020-01-23: last of 2 revisions
2018-06-22: received
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      author = {Daniel P.  Martin and Marco Martinoli},
      title = {A Note on Key Rank},
      howpublished = {Cryptology ePrint Archive, Paper 2018/614},
      year = {2018},
      note = {\url{}},
      url = {}
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