Kademlia... that's distributed hash tables, aka DHT. DHT uses servers to lookup and locate nodes. Therefore it's not truly distributed, thus not P2P.
In contrast, the Xnode protocol, upon which the XBridge is based, is completely serverless in operation and truly distributed.
So what exactly will XBridge use?
.
, and a bit of DHT too for scalability.
Completely serverless of course.