The world is facing an increasing threat from quantum computers. All widely deployed public key cryptosystems, namely, RSA, Diffie-Hellman and ECC, will be broken due to Shor’s algorithm running on a quantum computer. This has a catastrophic impact on not only our blockchain community, but also the security of the whole Internet infrastructure.

To mitigate this threat, NIST started a process in 2016 to select post-quantum cryptography candidates for standardization. NIST is the de facto authority in cryptography standardization. To name a few, it has standardized AES, SHA2, SHA3, etc. The candidate PQC algorithms is thought to replace most of our existing public key infrastructure, i.e., the aforementioned RSA, Diffie-Hellman and ECDSA schemes.

NIST received over 80 submissions from world's top universities and industry leaders. After 4 years of evaluation, and 3 rounds of eliminations, NIST finally announced 7 finalists this July, among which, 4 are public key encryption algorithms, and 3 are digital signature schemes.

We are proud to share that Algorand's cryptography engineer, Dr. Zhenfei Zhang, working with collaborators from IBM, NTT, NCC, Qualcomm, etc., contributed to 2 candidates:

1. NTRU - a public key encryption scheme. You can experiment NTRU on Google Chrome at this link.
2. Falcon - a digital signature scheme. Falcon is a drop in replacement of ECDSA and Ed25519, two common signatures used by our community. Falcon also enables state-of-the-art post-quantum ring signatures, a privacy enhancement method for blockchains.

In a related topic, Zhenfei also contributed to LAC: Practical Ring-LWE Based Public-Key Encryption with Byte-Level Modulus, a first award winner of Chinese PQC competition, hosted by Chinese Association for Cryptologic Research.

Algorand will continue to lead innovation in applied cryptography and looks forward to seeing more news from this standardization effort!