[Security] DOS of route messages

[Aras14HD]

What vulnerability did you find?
A node could stop route messages from reaching the intended recipient.

How do you attack using the vulnerability?
A node could report their distance to the victim as 0 or even set their UUID to that of the victim, so that route messages intended for the victim would be routed to them instead.

How might you fix this

1. A broadcast subtype could be added as a fallback, that would be used if responses to route messages, that aren't "not reachable" (status 1), all have the wrong signature.
2. If a node that has a distance of 0 to the recipient of a route message or is the recipient of a route message, responds with (only) "not reachable" (status 1), the node relaying the route message to them will calculate the distance without them, internally set their distance to on higher than itself and send the route message again.

[Aras14HD]

#12 would also prevent circumventing this by sending garbage back.

[Aras14HD]

I combination with #12 a solution might be to include public data (unix timestamp + random number), that will always be signed by the recipient, in every message.
Like this you guarantee, that if someone tries to block a message, it is noticed.