What authentication techniques can be used by QKD Systems?
The standard answer in the research literature is to use information-theoretically secure message authentication codes, typically universal hashing (aka Carter-Wegman authenticators).  Of course, you could use computationally-secure message authentication codes, like CMAC or HMAC, if you wanted, though that would partly defeat one of the reasons for using QKD.

That said, in practice QKD is a bit silly.  QKD solves a problem that most people don't have, so it is basically a fancy useless toy (albeit a very expensive one).  If you're considering using QKD in some practical deployment, my advice is: skip the QKD, and just use a TLS or IPSec VPN.  There, I saved you $50,000; don't spend it all in one place!