Den 18 mar 2015 23:38 skrev "Dennis Sullivan" <dennis.jm.sullivan@gmail.com>:
>
> Hello. This is my first time posting to this list. I wanted to ask your opinions on something relating to confirmation times.
>
> I recently read about a "transaction locking" proposal which claims to make it possible to accept 0-conf transactions with guarantee they will get mined. This seems rather dubious to me, because if there was merit to the system, I would have already expected to see discussion on this list regarding it.

Sounds like it would be weak to sybil attacks (deterministically choosing my own nodes sounds great!), and of course Finney attacks (single-block reversal) and defecting miners (what are you gonna do, punish miners with limited network connectivity as well? You'll risk forking the network).

Zero-conf is only safe if nobody's actively trying to attack you. It has no inherent security in and of itself. For low values the risk is usually tolerated. For large values there's too much risk of making yourself a target.