Post-quantum Cryptography

Post-quantum cryptography (PQC) is based on the notion that Quantum computers, when and if developed, could potentially break existing public-key encryption algorithms, necessitating the development of new cryptographic methods to prevent such attacks. Post-quantum cryptography is based on mathematical problems that are believed to be resistant to quantum attacks.

A NIST document says “Conventional cryptographic algorithms select two very large prime numbers — which are only divisible by 1 and themselves — and multiply them to obtain an even larger number. While multiplying the prime numbers is easy and fast, it’s far more difficult and time-consuming to reverse the process and figure out which two prime numbers were multiplied together, and that’s what a conventional computer would have to do to break this encryption. These two numbers are known as the “prime factors.” For large enough numbers, a conventional computer has been estimated to need billions of years to figure out these prime factors.

“A sufficiently capable quantum computer, though, would be able to sift through all of the potential prime factors simultaneously, rather than one by one, arriving at the answer exponentially more quickly. Experts have begun referring to such a mature device as a “cryptographically relevant” quantum computer. Instead of billions of years, it’s possible a quantum computer could solve this puzzle in days or even hours, putting everything from state secrets to bank account information at risk.”

Various government mandates, including the United States’ Commercial National Security Algorithm (CNSA) 2.0, the European Union’s Network and Information Security (NIS) 2, Digital Operational Resilience Act (DORA), and other regulations require enterprises to update IT infrastructures with post-quantum encryption algorithms and zero trust architecture.