Note: To clear up any confusion on the publication release date - this
publication was approved in April 2010, but there was some editing and
formatting issues that needed to be taken care of before it was
released to the public. This document was released this week (Aug.
2010). That is the reason why the date on the publication says April
2010 - it was approved in April.
The URL to SP 800-81 Rev 1. on the CSRC website is:
http://csrc.nist.gov/publications/nistpubs/800-81r1/sp-800-81r1.pdf