Contents
In brief
One project replaces public-key algorithms with new classical ones. The other uses quantum physics to share a key. They solve different problems.
Original CloudExchangers explainer. It describes established public practice and labels the desk’s judgment as analysis. It is not a report of a newly announced event.
Two names that get welded together
Post-quantum cryptography, or PQC, is a family of classical algorithms designed so that a large quantum computer running something like Shor’s algorithm does not break them. You run them on the computers you already have. Quantum key distribution, or QKD, uses quantum states sent over a physical link so that eavesdropping disturbs the states and can be detected. QKD needs special hardware and a path. It does not replace the need to authenticate, and it does not by itself encrypt a data center full of ordinary TLS.