Ben Laurie wrote:

This document is available on the Web, at:

http://www.xopen.org/public/tech/security/pki/casm/casm.htm

see also my "addendum" to Anderson & Roe's paper (which is actually a critique of the above proposal, rather than RH itself) at:

http://www.algroup.co.uk/crypto/rh.html

Ben rightly points to a complete and handsome forebear of our gap-toothed descendant. We withdraw ours. Thanks Ben. And thanks for your "addendum" to A&R.