libpep

A cryptographic library for polymorphic encryption and pseudonymization (i.e. the PEP framework), based on the ElGamal encryption scheme. It enables unlinkable, end-to-end encrypted data sharing with integrated blind pseudonymization, potentially distributed over multiple parties to prevent trusting single points of failure. It enables users to privacy-friendly share specific attributes about data subjects, without knowing the other user’s pseudonym for that data subject. This prevents unauthorized identification or linkage with other data. Communication can also be asynchronous (i.e. the sender does not need to specify the recipient at time of sending), meaning that encrypted data can for example securely be stored at a cloud storage, and later be shared with multiple recipients while remaining encrypted and unlinkable. The library is written in Rust, with bindings for WASM (TypeScript and JavaScript) and Python.