Beam Me Up Scotty … It’s a Whole New Crypto World
Passing symmetric keys in a post-quantum world with Kyber-CRYSTALS
Published in
6 min readMay 9, 2021
As if you didn’t know, quantum computers will put an end to all of our popular public-key and key exchange methods (ECC, RSA and Discrete Logs). And so NIST has been working on defining a standard for the best method to replace these, and recently they made their announcement on the final of the PQC (Post Quantum Cryptography) standardization process. For Public-Key Encryption and KEMs (Key Encapsulation Mechanisms) we have:
- Classic McEliece. This has been around for around 40 years, and has been shown to be fairly resistant to attack. It produces a fairly long encryption key, but produces a fairly small amount of ciphertext.
- CRYSTALS-KYBER (Lattice). Uses LWE (Learning with Errors) with lattice methods. A new lattice attack was discovered within the period of the assessment [1], but it is hoped that an updated version of KYBER can be produced for the final assessment. NIST have some worries about its side-channel robustness, and is a strong contender for KEM.
- NTRU (Lattice). This is a traditional structured lattice based approach, and has been around for longer than the other lattice methods — showing that it is perhaps more robust against attack and against intellitecual…
