Quantum Resistance

Using Shor’s algorithm on Quantum Computers, it is possible to break cryptography schemes that current blockchains use. Blockchains such as Bitcoin, Ethereum, Dogecoin are vulnerable to quantum computers in various ways because they use elliptic curve cryptography that can be broken using quantum computers.

Account security will be broken if the underlying cryptography schemes are vulnerable. This means that funds can be withdrawn maliciously and double spend transactions made possible if account security is compromised.

Quantum Resistant cryptography also known as “post quantum cryptography” refers to cryptography algorithms that are resistant to quantum compute-based algorithms. NIST which is a standards body is conducting a program to identify post quantum cryptography algorithms. The finalized candidates from this program will be selected for standardization. Standardization means what software and hardware vendors from around the world will adopt these algorithms in their products, such as operating systems, graphics cards and IOT devices.

Quantum Coin will use these post quantum algorithms to secure accounts as well as inter-node communication. In addition, management, and reporting APIs of the blockchain will also use post-quantum TLS.

Hybrid PQC Dilithium + ed25519 (EdDSA) + SPHINCS+, is used to secure accounts in Mainnet. Dilithium (ML-DSA) and SPHINCS+ (SLH-DSA) is a NIST standardized post quantum cryptography algorithm while EdDSA (ed25519) is a part of NIST FIPS 186-5 standard. Inter-node communication is secured using Kyber. Quantum Coin is the first if not one of the first to secure both accounts and inter-node communications using quantum resistant cryptography. The inter-node communication uses a hybrid model, in which the final client and server encryption keys are derived similar to TLS as detailed in RFC 8446. Kyber (ML-KEM) is used for key exchange and the key material thus derived is used as input to HMAC HKDF functions (RFC 5869). However unlike TLS, instead of trusting the certificate, the key of the other node is instead trusted. The private key corresponds to the Hybrid classical + post-quantum key-pair used to secure the account using digital signatures.