I think, it is a must, that the miners personally identified. Think an history of bitcoin - and a possible future:
- firstly CPU mining. (technology A - public)
- then GPU mining. (technology B - public (fortunately) but technology A not an opponent)
- ... some other public technology, pools, merged mining, and so on...
- in future: technology X coming - (not published - owned by some (or one) persons/firms/...) AND (technology A and technology B and other public technologies aren't an opponent) - the controll of members of Bitcoin forum over bitcoin (and our "money") loosed!
And about some possible identification attribute of a person (or a computer):
I think not a 100% identifying - I am engineer and not a Mathematicians

- me enough
for example the last in the list...
and
How is loyalty and reliability determined?
- Guest
- Newbie
- Jr. Member
- Full Member
- Miner
- Full Member + an trusted public key - Sr. Member
- Hero Member
- + Moderators