Paper 2011/254

Using the Cloud to Determine Key Strengths

T. Kleinjung, A. K. Lenstra, D. Page, and N. P. Smart


We develop a new methodology to assess cryptographic key strength using cloud computing, by calculating the true economic cost of (symmetric- or private-) key retrieval for the most common cryptographic primitives. Although the present paper gives the current costs, more importantly it provides the tools and infrastructure to derive new data points at any time in the future, while allowing for improvements such as of new algorithmic approaches. Over time the resulting data points will provide valuable insight in the selection of cryptographic key sizes.

Note: Update analysis with 2012 Amazon prices

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Published elsewhere. Unknown where it was published
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nigel @ cs bris ac uk
2012-05-17: last of 2 revisions
2011-05-25: received
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      author = {T.  Kleinjung and A. K.  Lenstra and D.  Page and N. P.  Smart},
      title = {Using the Cloud to Determine Key Strengths},
      howpublished = {Cryptology ePrint Archive, Paper 2011/254},
      year = {2011},
      note = {\url{}},
      url = {}
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