So, Crystal Dilithium is a signature scheme built on lattice-based cryptography. Cryptographic lattices are one of the oldest forms of cryptography. A quantum computer is coming soon into our lives. However, it will be powerless against cryptographic lattices.
How did Crystal Dilithium appear?
Here it should be recalled that the development of new standards for quantum-resistant cryptography has long been at the official level. The American National institute of standards and technology – NIST – deals with it. The organization considers the proposals for new encryption algorithms and digital signatures instead of outdated RSA and ECDSA.
In the first round held on April 2018, 69 applications for post-quantum encryption algorithms and digital signatures were submitted to NIST. In August 2019, the second round of post-quantum algorithms selection was held. Crystal Dilithium was presented by one of its creators. This is IBM cryptographer Vadim Lyubashevsky. As a result, only 17 candidates for the new standard of the encryption algorithm and 9 candidates for the digital signature were selected.
The authors of Crystal Dilithium are the group of cryptographers who developed BLISS-II digital signature standard in 2013. It can be considered the predecessor to Dilithium. BlISS could be a candidate for the new standard. But Crystal Dilithium is better for this role. because the vulnerability inherent in BLISS was corrected in Dilithium.
How is Crystal Dilithium better than other post-quantum digital signatures?
NIST conducted the study of the selected proposals. And it came to the conclusion that Crystal Dilithium in many respects is one of the most promising variants for post-quantum digital signature. Crystal Dilithium has a number of advantages over other submitted algorithms:
– It can be easily implemented in existing systems. This is possible due to the versatility of this algorithm;
– The small size of the public key. It is one of the major advantages. This affects the transaction speed in the systems that will use Crystal Dilithium;
– Dilithium can serve as a base for the creation of signatures with zero-knowledge;
– A high level of safety in the post-quantum future.
Crystal Dilithium in DapCash
We are one of the first teams who implemented Crystal Dilithium in the ready product. And this achievement gives us new opportunities. Our next step is to develop post-quantum signatures with zero-knowledge on the basis of Dilithium.
So far, these signatures are very limited. One of the most famous is Picnic developed by Microsoft. And of course, Picnic is already embedded in DapCash blockchain.