Development of Relativistic Cryptography – DEREC

The goal of project DEREC is to demonstrate the feasibility of relativistic cryptography, a new and exciting research direction which takes advantage of the No Superluminal Signaling (NSS) principle in order to perform various cryptographic tasks. NSS states that no information carrier can travel at a speed greater than the speed of light. By enforcing timing and location constraints, it becomes possible to exploit the NSS principle in order to achieve information theoretic security instead of computational security for a broad class of cryptographic tasks.

The advantage of relativistic cryptography is that it offers long-term security, independent of any future advance in computer software or hardware (including quantum computing). In addition to providing trust and longer lifetime of our cryptosystems, it also ensures retroactive security: a malevolent organization could store encrypted data right now and wait until it reaches sufficient computational power to decrypt them in the future. Since more and more sensitive data gets moved to the cloud, this issue is certainly of the utter importance for all actors of our modern society.

Most cryptographic proposals rely on computational assumptions and therefore fail to offer long-term and retroactive security. Without being too pessimistic, we can assert that several such schemes will be obsolete in the 10 to 30 years to come. Proposals for long-term security already exist, but involve quantum hardware and therefore remain expensive and difficult to develop at large scale, despite real technological advances in the past few years.

DEREC is a unique proposal that combines the best of both worlds. On the one hand, it provides information-theoretic security and therefore long-term security based on the NSS principle. Since falsifying this principle would imply the possibility of traveling back in time, we feel confident that it is as good as a cryptographic assumption can get! On the other hand, the necessary hardware to implement relativist cryptography is very standard and available today. Our cryptographic applications will use specific timing and location constraints but they can be achieved very easily in practice. In particular, we will need fast and low latency communications, but not as efficient as the already existing solutions that have been developed for high frequency trading for instance. This means that the required technology is already available and can be transferred to relativistic cryptography easily.

We will focus on secure multiparty computation, with applications such as voting schemes, secret auctions, or password-based authentication schemes. Our final goal is to implement these protocols, with proven security, at the end of the 4-year project so that they can be deployed on a larger scale in the 5 to 10 years to come. We limit ourselves to a few tasks in this project for pragmatic reasons but the potential benefits of relativistic cryptography go far beyond them.
Now is a perfect for the development of this technology: on top of hardware accessibility, recent preliminary results, notably by the project leader, showed that relativistic cryptography primitives can be efficiently implemented. It is a very positive and exciting time for relativistic cryptography.

The team is young, dynamic and covers all the needs for the success of the project. The finality of the project will foster strong collaboration and open broad perspectives with both the academic and the industrial world. For the project coordinator, this project would be a decisive step in his career, giving him the opportunity to manage a team including students. It will also be an important step towards applying to an ERC grant.
The demanded help is 225k€ + administrative overhead and will be used for funding a PhD student, a 1 year postdoc, equipment and academic travels.