The National Institute of Standards and Technology (NIST) has introduced the first three standards for cryptographic algorithms that are resistant to quantum computer attacks. The first standardized algorithm (CRYSTALS-Kyber) defines a method for key encapsulation and is intended for secure data exchange, while the other two (CRYSTALS-Dilithium and Sphincs+) implement variants for generating digital signatures that can be used for authentication tasks. To avoid confusion, the standardized variants of the algorithms have been renamed: CRYSTALS-Kyber to ML-KEM, CRYSTALS-Dilithium to ML-DSA, and Sphincs+ to SLH-DSA. The selected algorithms have been under development since 2016 and are the winners of the previously announced NIST competition for post-quantum cryptography algorithms.
Recently emerging quantum computers are drastically faster at solving the problems of factoring natural numbers into prime factors (RSA) and discrete logarithm computation on elliptic curves (ECDSA), which underpin modern asymmetric public key encryption algorithms that are effectively unsolvable on classical processors. At the current stage of quantum computer development, their capabilities are not yet sufficient to break existing classical encryption algorithms and digital signatures based on public keys, such as ECDSA, although it is expected that this situation could change within this decade.
Accepted standards:
- FIPS 203 is regarded as the primary standard for using the CRYSTALS-Kyber algorithm (ML-KEM - Module-Lattice Key-Encapsulation Mechanism) for facilitating key exchange between parties involved in data encryption and decryption. The CRYSTALS-Kyber algorithm utilizes cryptographic methods based on solving lattice theory problems, the solving times of which do not differ between classical and quantum computers. Advantages of the selected algorithm include relatively small key sizes and high operating speed. data encryptionFIPS 204 is the primary standard for digital signatures, based on the CRYSTALS-Dilithium algorithm (ML-DSA - Module-Lattice Digital Signature Algorithm), which, like CRYSTALS-Kyber, is based on lattice theory.
- FIPS 204 is the primary standard for generating digital signatures based on the CRYSTALS-Dilithium algorithm (ML-DSA — Module-Lattice Digital Signature Algorithm), which, like CRYSTALS-Kyber, is based on lattice theory.
- FIPS 205 is an alternative standard for generating digital signatures that utilizes the Sphincs+ algorithm (SLH-DSA — Stateless Hash-Based Digital Signature Algorithm), which applies methods of hash function-based cryptography. Sphincs+ lags behind CRYSTALS-Dilithium in terms of signature size and speed, but is based on fundamentally different mathematical principles, meaning it will remain effective even if lattice-based algorithm methods are compromised.
In addition, by the end of the year, a fourth standard — FIPS 206 is expected to be approved, intended for use with digital signatures and based on the FALCON algorithm. Like the CRYSTALS-Kyber and CRYSTALS-Dilithium algorithms, it is based on solving lattice theory problems, but unlike them, it is focused on applications where minimal signature size is required. The standardized version of the FALCON algorithm will be delivered under the name FN-DSA (FFT (Fast Fourier Transform) over NTRU-Lattice Digital Signature Algorithm). By the end of the year, algorithms for creating alternative standards for general encryption are also expected to be selected, which will be based on working principles different from those employed in FIPS 203 based on the CRYSTALS-Kyber algorithm.
Source: opennet.ru
