This repository stores Maude's system modules that construct the symbolic models of three postquantum cryptography schemes. Specifically, the selected schemes are Key Encapsulation Mechanisms (KEMs). The symbolic modules allow us to perform invariant analysis, find a Man In The Middle (MITM) attack, and model checking of Liveness, Fairness and Security properties. The analyzed KEMs are:

• Kyber
• Bike
• Classic McEliece

Please check the corresponding publication for further insights on the symbolic specification and verification of Kyber.

For a complete detailed explanation of the framework along with three use cases with the above mechanisms, please see the journal paper of PeerJ Computer Science.

The repository is divided into three main folders, one for each of the specified KEMs. Each folder stores two kinds of files: one txt file and four maude files. The txt file contains basic information and a series of notations on the specified KEM. The maude files are:

• KEM.maude: Contains the full specification using the framework.
• KEM-PREDS & KEM-CHECK: Contain the necessary modules to perform model checking with Maude.
• KEM-test.maude: Stores a series of commands to (i) perform invariant analysis through the search command and (ii) verify three properties with the LTL Model Checker.

where KEM is either kyber, bike or cm respectively for each selected protocol.

In order to perform invariant analysis and model checking one has to:

1. Have Maude 3.3 installed. It can be downloaded from the official download page.
2. Download this repository and extract the contents.
3. Open a terminal in the parent folder of the downloaded repository.
4. Start Maude by following the instructions. Maude can be initiated by running the ./maude.darwin64
5. Load a testing file with the command load KEM-test.maude, where KEM has to be either kyber, bike or cm. The code inside testing files will perform the following commands.
   1. Invariant analysis with the search commands.
   2. Model checking with the reduce commands.