Alex Davidson, LASIGE integrated member, was invited to take part in a panel discussion on “The path to the post-quantum transition: discussing quantum-safe cryptography” at the C-DAYS 2025 conference, promoted by the National Cybersecurity Centre (CNCS), which took place in Estoril from 24 to 26 June 2025.

The discussion was launched after the following introductory notes “Cryptographic systems are vital to protect the confidentiality and authenticity of data. The robustness of cryptographic algorithms relies on the computational complexity of certain mathematical problems. Peter Shor demonstrated in 1994 that an algorithm designed to run on a quantum computer would be able to efficiently solve some of these problems, which would imply breaking several public key cryptographic mechanisms such as RSA. Although there is currently no cryptographically relevant quantum computer, this threat is imminent. On the one hand, threat actors can intercept encrypted information today to decrypt it later when such a computer appears (“Store Now, Decrypt Later” attacks); and, on the other hand, transitioning from the current cryptographic algorithms to quantum safe cryptography is a very complex endeavour and is expected to take a long time. The threat to cybersecurity underlying quantum computing can be curbed by a timely, comprehensive, and coordinated transition to post-quantum cryptography and other quantum safe solutions. In this panel, we will discuss the state of the quantum threat, what the quantum safe solutions are as well as the challenges associated with a large-scale transition to novel cryptographic algorithms”.

C-DAYS is a national reference event in the field of cybersecurity, with the aim of reinforcing best practices in this area and laying the foundations for a more resilient national cyberspace, through knowledge sharing and joint reflection by the different cybersecurity communities. The central theme of this 11th edition is ‘+Resilience’, calling for a more proactive role for cybersecurity in Portugal, under the impetus of the transposition process of the NIS 2 Directive (EU) 2022/2555, which aims to strengthen cybersecurity throughout the European Union.