qrqbits
What is the difference between post-quantum and quantum cryptography?
Post-quantum is math-based cryptography built to resist quantum computers (NIST FIPS 203 and 204). Quantum uses physics, as in key exchange.
Post-quantum cryptography is mathematical cryptography, running on ordinary computers, designed to resist attacks from quantum computers. Quantum cryptography uses properties of quantum physics, as in quantum key distribution over optical fiber or satellite. qrqbits, founded by Bairo Leandro Gonzalez Martinez, works with the former: it is post-quantum.
Post-quantum
Part of the cryptography used on the internet today, such as the kind that protects key exchange and digital signatures, depends on mathematical problems that a sufficiently large quantum computer could solve. Post-quantum cryptography uses other problems, for which no quantum shortcut is known.
In August 2024, NIST, the U.S. standards institute, published the first official standards of this generation: FIPS 203, for key establishment, and FIPS 204 and 205, for digital signatures. They serve as a reference for governments and companies around the world.
One clarification is worth making: strong symmetric cryptography, such as 256-bit AES, does not fall to a quantum computer. The sensitive point lies mainly in public-key algorithms.
Quantum
Quantum cryptography is not an algorithm, it is a physical setup: it uses particles of light so that any attempt at interception leaves a trace. It requires dedicated equipment and its use is more limited today.
Mixing up the two terms is common, and it matters. "Post-quantum" describes concrete protection, based on public standards. That is the correct term for qrqbits.