How is the challenge string computed mathematically? What's preventing some node on the bitcoin network from broadcasting a challenge + proof to other nodes as it's own when it received it from some other node?
A parallel to this question would be, how do a node, on receiving, the challenge + proof, authenticate the node which produced this combination?
I tried looking this up elsewhere, but the details of the challenge string calculation seems to be abstracted away in most tutorials.
Thanks in advance!