prop295: revise proposal and determine feasability
Proposal 295 is:
> Filename: 295-relay-crypto-with-atl.txt
> Title: Using ADL-GCM for relay cryptography (solving the crypto-tagging attack)
> Author: Tomer Ashur
At:
https://github.com/torproject/torspec/blob/master/proposals/295-relay-crypto-with-atl.txt
issue