The Difference Between Quantum Cryptography & Post-Quantum Cryptography

(FedTechnology) One particular element of quantum computing that can be seen as both a positive and a negative is its ability to build and break encryption algorithms. This is especially troubling to the government and could have special implications for the military. Plus, there is a very real risk today that individuals may be intercepting and storing encrypted internet traffic now for decryption later, when a large enough quantum computer is available.
Quantum cryptography, also referred to as quantum communication or quantum security, offers a theoretically secure solution to the key exchange problem, namely quantum key distribution (QKD).
The practice takes advantage of the “no change theory,” which dictates that no quantum presence can be interrupted without the interruption being detected. Photon particles generate encryption keys through their properties.
If quantum cryptography makes it a hundred times more difficult for “bad guys” to crack systems and steal the data — or an improvement of exponentially more profound impact — then federal IT decision-makers have a duty as public servants to seriously explore and invest in this technology.
While still an emerging technology in terms of quantum cryptography, QKD, while limited, does exist today in solutions like IBM’s lattice-based cryptographic suite, known as CRYSTALS, Sutor says.
post-quantum cryptography consists of algorithms designed to withstand cyberattacks should quantum computers become powerful enough. Once that happens, says Dustin Moody, a mathematician at NIST, post-quantum encryption will come into play on a large scale.
“For most organizations, quantum encryption or QKD is not what they’re going to need. It’s most likely going to be post-quantum encryption,” Moody says.
One of the next important steps to make quantum-safe cryptography more widely adopted by government and industry, says Sutor, is standardization, which NIST is currently undertaking.
Today, NIST is evaluating post-quantum algorithms with an eye toward choosing a standard for all post-quantum cryptography.