Is Quantum Computing an Existential Threat to Blockchain Technology?
although there are but a handful of quantum computing algorithms, one of the most famous ones, Shor’s algorithm, allows for the quick factoring of large primes. Therefore, a working quantum computer could, in theory, break today’s public key cryptography.
.. The NSA announced in 2015 that it was moving to implement quantum-resistant cryptographic systems. Cryptographers are working on quantum-resistant cryptography, and there are already blockchain projects implementing quantum-resistant cryptography. The Quantum Resistant Ledger team, for example, is working on building such a blockchain right now.
What makes quantum-resistant or “post-quantum” cryptography, quantum resistant? When private keys are generated from public keys in ways that are much more mathematically complex than traditional prime factorization.