During October 2025, Rui Li focused on improving cryptographic reliability in the Mbed-TLS/mbedtls-framework repository by addressing a critical bug related to AES-XTS key size compatibility. Rui enhanced the Python-based test automation suite to correctly generate and validate double-size AES-XTS keys, ensuring that only supported key sizes are processed during testing and builds. By tightening key-size validation logic and refining algorithm compatibility checks, Rui reduced false failures in continuous integration and improved cross-platform crypto behavior. This work demonstrated depth in Python scripting, cryptography, and test automation, resulting in more robust and maintainable cryptographic test coverage for the project.