Experiments with Universal Composability in EasyCrypt
This repository contains experiments in formalizing Universally Composable (UC) Security using the EasyCrypt proof assistant. This is joint work between Boston University faculty
- Ran Canetti (firstname.lastname@example.org)
- Assaf Kfoury (email@example.com)
- Alley Stoughton (firstname.lastname@example.org)
- Mayank Varia (email@example.com)
with the assistance of research students
In our architecture, functionalities (real protocols, or ideal functionalities) have hierarchical addresses, and we build abstractions that route messages to their destinations, modeling the coroutine-style communication of UC.
Secure Message Communication
In our first full example, we formalized the proof of the UC security of secure message communication using a one-time pad that's agreed using Diffie-Hellman key exchange. Our goal in this example was to test our EasyCrypt UC architecture, illustrating how instances of UC's composition operation and theorem may be formalized in EasyCrypt.
This work is described in the extended version of the CSF 2019 paper, EasyUC: Using EasyCrypt to Mechanize Proofs of Universally Composable Security.
UC Domain Specific Language
We have designed and implemented a prototype parser and typechecker for a domain specific language (DSL) for expressing functionalities (protocols and ideal functionalities) and simulators. The DSL will allow crypto theorists to easily write and understand functionalities and simulators. The DSL design was driven by the expression of functionalities and simulators in our EasyCrypt architecture for UC. But it allows expression at a much higher level, avoiding all the message-routing boilerplate. DSL type-checking will catch errors like badly formed messages (e.g., ones with bad source addresses) or simulators that interfere with communication between environment and adversary. When DSL code is translated into EasyCrypt's procedural programming language, message-routing boilerplate will be automatically generated.