encrypt locally preferred socket

[Logan007]

To not leak any local network information, I would love to see the -e-provided locally preferred socket encrypted for transmission to the supernode, for storage, and transmission back to the querying edge. The supernode shall not be able to decrpyt it.

I guess, we should use the -k provided key as it is known only to the edges.

[fengdaolong]

Although it is impossible to imagine what kind of security problems will be caused (unless there are loopholes in the edge itself), it is safer to do so.

[lucktu]

agree

[Logan007]

For the sake of compatibility throughout the 3.x series, this can be implemented at 3.9/4.0 at the earliest.