Paper 2014/504

A Provable Security Analysis of Intel's Secure Key RNG

Thomas Shrimpton and R. Seth Terashima


We provide the first provable-security analysis of the Intel Secure Key hardware RNG (ISK-RNG), versions of which have appeared in Intel processors since late 2011. To model the ISK-RNG, we generalize the PRNG-with-inputs primitive, introduced Dodis et al. introduced at CCS'13 for their /dev/[u]random analysis. The concrete security bounds we uncover tell a mixed story. We find that ISK-RNG lacks backward-security altogether, and that the forward-security bound for the ``truly random'' bits fetched by the RDSEED instruction is potentially worrisome. On the other hand, we are able to prove stronger forward-security bounds for the pseudorandom bits fetched by the RDRAND instruction. En route to these results, our main technical efforts focus on the way in which ISK-RNG employs CBCMAC as an entropy extractor.

Available format(s)
Publication info
A major revision of an IACR publication in EUROCRYPT 2015
provable securityrandom-number generatorentropy extraction
Contact author(s)
sethterashima @ gmail com
2015-02-18: revised
2014-06-26: received
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Creative Commons Attribution


      author = {Thomas Shrimpton and R.  Seth Terashima},
      title = {A Provable Security Analysis of Intel's Secure Key RNG},
      howpublished = {Cryptology ePrint Archive, Paper 2014/504},
      year = {2014},
      note = {\url{}},
      url = {}
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