What is Post-Quantum Cryptography

Quantum-resistant blockchains refer to cryptographic processes that are resistant to attacks via quantum computers. Present public-key algorithms depend on the difficulty of deciphering the discrete log and factorization problem of large prime numbers. Shor's algorithm can be used to break the hash signatures by quantum computers. Therefore, it is necessary for the development of a post-quantum secure signature scheme or quantum-resistant blockchain for post-quantum blockchain security. This chapter will discuss the impact quantum computers are predicted to have on public key cryptography based on the following topics: quantum computers, public key cryptography, quantum threat to PKI, Shor's and Grover's algorithms, post-quantum cryptography, and quantum-resistant blockchain.