LAK WITH PAIRS AND TAGS
[D] Lucca Hirschi, David Baelde, and Stéphanie Delaune. A method for unbounded verification of privacy-type properties. Journal of Computer Security, 27(3):277–342, 2019.
R –> T : nR T –> R : <nT,h(<<nR,nT>,tag1>,k)> R –> T : h(<<h(<<nR,nT>,tag1>,k),nR>,tag2>,k)
We consider tags in the messages (tag1 and tag2) to ease the proof.
This is a “light” model without the last check of T. ******************************************************************************
The next two lemmas are more precise variants of the previous one, specifically for R1. They are useful to simplify the try-find construct in the output of that action. Note that the proofs of the next two lemmas are almost identical, but their statements differ in the treatment of index k, and they deal with distinct systems.
Equality used to rewrite the try-find in R1 so that its condition can be discharged using fadup.