An introduction to Post-Quantum Cryptography for the practitioner

A technical introduction to Post-Quantum Cryptography with a focus on what practitioners need to know.

We start with the why: Shor’s algorithm efficiently solves the factoring, discrete logarithm, and period-finding problems — breaking RSA, Diffie-Hellman, and Elliptic Curve cryptography. For everything else, Grover’s algorithm gives a square-root speedup over classical brute force, meaning symmetric keys and hashes need to roughly double in size.

From there we look at which of today’s algorithms are at risk, what the NIST PQC standards bring to the table, and how to start preparing your systems for a crypto-agile, post-quantum world.