Using special purpose hardware and the physics of quantum mechanics you can distribute cryptographic keys to be used in a standard symmetric key cryptography way, but is it worth it?
Why would we want to distribute keys this way? What are the advantages other than allowing you to tell whether anyone has been “eavesdropping” on the line.
In this video we discuss the pros and cons of using quantum key distribution. Interestingly, the NSA certainly don’t want us to do it… so do you need a QKD/QRNG?