[Cfrg] Request For Comments: OCB Internet-Draft

Ted Krovetz <ted@krovetz.net> Wed, 13 July 2011 16:42 UTC

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From: Ted Krovetz <ted@krovetz.net>
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Date: Wed, 13 Jul 2011 09:42:21 -0700
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Subject: [Cfrg] Request For Comments: OCB Internet-Draft
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I have just submitted an internet-draft for OCB to the IETF.


I'd appreciate any comments you may have on how to make the draft better.

OCB is a blockcipher-based authenticated-encryption scheme. It is significantly faster than any other blockcipher-based AE scheme that I am aware of. On Intel's current Sandy Bridge processors it encrypts and authenticates 4K messages at 0.9 cpu cycles per byte of message, and processes a weighted mix of message lengths at 1.3 cpb (5% 44B, 15% 552B, 20% 576B, 60% 1500B).

OCB has undegone refinements over the years to allow authentication of associated data and improved performance. This is the second (and last) revision. It was presented at FSE this year


Associated notes and performace data are at


We intend to convert the internet-draft into an RFC and also submit OCB to the NIST blockcipher modes-of-operation project.

There are several patents that may apply to OCB. We are in the process of trying to get all parties to pool their patents and liberalize their use.

Thank you,
Ted Krovetz