PQCrypto Releases First Recommendations for Post-Quantum Computing Cryptography

Security researchers from the European project PQCrypto have issued an advice to already introduce cryptographic security that cannot be cracked by quantum computers for a long time.

The report recommends cryptographic techniques that can withstand quantum computing for various encryption methods, such as symmetric encryption, symmetric authentication, public key encryption and signing. The recommendations have been chosen because the researchers believe that they will remain safe for a long time and not because they are efficient. Future research should lead to more usable and more efficient systems.

Despite the fact that the first workable quantum computers are not expected within ten years, the researchers consider it wise to protect systems against quantum computers now. The machines will probably be able to crack several commonly used methods by then. For example, asymmetric methods such as RSA keys can be cracked in a relatively short time by performing quantum calculations. Symmetrical methods with long keys, on the other hand, are also safe from quantum violence.

For the symmetric encryption methods, the team recommends AES or Salsa20 with a key length of 256 bits. For symmetric authentication, the researchers recommend using the Galois/Counter Mode process and Poly1305. For protecting public keys, McEliece is recommended because it has been studied since 1978 and has so far resisted attacks well, including those using quantum computers. Digital signatures should use XMSS or Sphincs. One of the problems is that the memory required to store the public keys becomes very large.

The problem with potentially future quantum computers is that, for example, someone can now decide to store encrypted messages and be able to decipher them in the future. That is why PQCrypto advises to work now on this future-proofing. The research program led by Tanja Lange of Eindhoven University of Technology started in April this year and has a research budget for the coming years totaling 3.9 million euros.