README

                  Otway-Rees cryptographic protocol
           Dominique Bolignano and Valérie Ménissier-Morain
                        GIE Dyade, VIP action
----------------------------------------------------------------------

This directory contains a description and a proof of correctness for
the Otway-Rees cryptographic protocol, usually used as an example for
                   formalisation of such protocols.

The file securite.v contains the description of:
  - the objects the protocol will manipulate
  - the knowledge of the reliable principals and of intruders
  - the guarantees on the keys provided by the certification authority
  - the protocol itself with the rel function cut in eight
    subfunctions rel[1-8]
  - three invariant properties (inv0, inv1 and invP): invP ensures
    that after any session with this protocol, the key that the
    certification authority provides to the reliable principals to
    encrypt their messages along this session is still unknown for
    intruders. 

The files inv0.v, inv1.v, invp.v contain the proof of each invariant
property. The two last proofs are rather long so they are cut in eight
files inv[1p]rel[1-8].v according to each subfunction rel[1-8].

-----------------------------------------------------------------------

Further information: a detailed description of this formalisation will
be available soon on http://www.dyade.fr/actions/VIP/Otway-Rees.dvi.

V. Ménissier-Morain
D. Bolignano
GIE Dyade, VIP action
Url: http://www.dyade.fr/actions/VIP/
December 1996