More than a decade ago, I was giving an introductory presentation on quantum cryptography, as I had done many times before. I discussed the basic concepts of quantum physics, quantum computers, and quantum cryptography. I ended it with the promise that when quantum computing went mainstream that most of our current digital encryption secrets, which rely on hard-to-solve large prime-number equations, would be immediately revealed to the world.
Most secrets have been protected with some form of asymmetric encryption ever since Whitfield Diffie, Mark Hellman and Ralph Merkle publicly revealed the concept in 1976 in their seminal paper called New Directions in Cryptography. Think RSA, SSL, TLS and HTTPS.