When quantum computers start breaking classic cryptography, then we better already have something stronger at hand - like quantum cryptography. The good news is that quantum cryptography is more simple than quantum computing.
For starters there are the quantum crypto protocols BB84 and E91.
| Name | Author(s) | Method |
|---|---|---|
| BB84 | Charles Bennet and Gilles Brassard | Polarized Photons |
| E91 | Artur Ekert | Entangled Photon Pairs |
On BB84 I wrote a seminar report in the course of my Bachelor studies.