Dilithium3

Dilithium3 is a parameter set of the Dilithium lattice-based digital signature scheme, submitted to the NIST Post-Quantum Cryptography standardization process as part of the CRYSTALS project. Dilithium itself relies on module learning with errors (Module-LWE) and module short integer problems (Module-SIS) in ideal lattices to produce signatures that aim to resist quantum attacks while remaining practical for everyday use.

The Dilithium family includes multiple parameter sets, such as Dilithium2, Dilithium3, and Dilithium5, which offer different balances of security and efficiency. Dilithium3 is designed to provide higher security than Dilithium2 while targeting more favorable performance than Dilithium5, making it a common choice for environments seeking stronger post-quantum protection without incurring the largest key and signature sizes.

In broad terms, a public key in Dilithium consists of a compact representation derived from a random matrix and a secret key comprises short polynomials used in the signing process. A signature contains several components that tie the message, randomness, and the public key together and can be verified by recomputing a hash-based challenge against the public key and the message. The exact algebra and encoding are defined by the parameter set and the reference implementation.

Security claims for Dilithium3 rely on the believed hardness of lattice problems and the absence of efficient quantum algorithms to break the underlying structure at the target security level. Like other post-quantum schemes, its concrete performance depends on hardware and software optimizations.

See also: NIST Post-Quantum Cryptography, lattice-based cryptography, CRYSTALS-Dilithium, Dilithium (family).