Development of a post quantum encryption for secure email communication

With the help of L3S, the developers of Tutanota want to integrate quantum-safe encryption into their e-mail client of the same name in an exemplary way, so that confidential communication cannot be read by third parties in the future either. This is also important for companies that want to secure their e-mails against industrial espionage or hacker attacks.

Before quantum computer-resistant encryption algorithms can be used in Tutanota, the project participants still have to complete a number of tasks: First of all, they have to evaluate various post-quantum algorithms, the standardization of which is currently being examined by the American National Institute of Standards and Technology (NIST). The researchers are also designing a hybrid communication protocol that supports Perfect Forwards Secrecy and can be integrated into Tutanota. Perfect Forward Secrecy means that part of an encryption system automatically and frequently changes the keys. The sense of the whole thing: If the last key used is compromised, only a small part of the data can be decrypted. In the hybrid protocol, the selected post-quantum algorithms are combined with established algorithms. The security of the communication is therefore guaranteed as long as at least the pre- or post-quantum algorithms are secure. This is important because post-quantum cryptography is currently still in the evaluation phase and new attacks against methods that are currently still considered secure could be found at any time.

Further steps in the project are security reviews of the hybrid communication protocol, the development of a prototype and the integration into Tutanota for testing and evaluation purposes – and finally the introduction of quantum computer resistant encryption in Tutanota, which can then be used by anyone free of charge. In the long term, e-mail security will increase enormously as a result.