INESC TEC researchers propose innovative cryptography solution for potential quantum computers threats

The solution proposed by Manuel Barbosa and João Duarte, researchers at INESC TEC, features a hybrid key-encapsulation mechanism (KEM), capable of addressing the demands of the dynamics of hybrid models that combine pre-quantum and post-quantum algorithms.

The issues around the security of personal data led to the ongoing relevance of cryptography in terms of new and constantly emerging threats. This area of computing, among other features, ensures the adequate functioning of tools like VPNs, messaging services or smart networks. Within cryptography, it is possible to find asymmetric key cryptography, a tool used in digital signatures — since it is composed of two types of keys: public, which can be widely disseminated, and private, only known to the owner.  

Anticipating future threats, scientists perceive large-scale quantum computers — which do not yet exist, but which may become a reality in the upcoming decades — a danger for this asymmetric key model, since these machines’ calculation potential will be able to “break” the entire security mechanism.  

A new generation of algorithms – post-quantum cryptography (PQC) – was the solution developed and presented by the community; is expected that the various sectors of society will gradually migrate to PQC over the next few years. In this process, the pre-quantum and post-quantum algorithms must be implemented together, to ensure that the responsibility for safety does not fall only on one of the parties. We’re talking about a hybrid model.  

According to João Duarte, researcher at INESC TEC, “these changes led to the need to create hybrid key-encapsulation mechanisms (KEMs). This tool allows anyone in possession of an entity’s public key to securely transfer it to said entity. Considering the increasingly widespread preference for the hybrid system, and given the doubts about its use (namely at the performance level), the researcher – in co-authorship with Manuel Barbosa – presented the X-Wing solution, as well as the respective security proof, in the paper The Hybrid KEM You’ve Looking For, published in IACR Communications in Cryptology.  

According to João Duarte, the goal is for X-Wing to be used “throughout the Internet”, since the paper presents concrete choices and safety proofs, which allow a total optimisation of performance and to declare the proposed solution as the “obvious choice” of hybrid KEM for most applications. The work also featured the contribution of the Max Planck Institute for Security and Privacy, Cloudfare, SandboxAQ and Rosenpass e.V. 

The researchers mentioned in this news piece are associated with INESC TEC and FCUP.