Assume that the notary public needs a 70watt light bulb to function (ignoring food costs, paper, etc). 8 hour day, so about a half kwh. That electricity with a new asic miner would get you about a half bitcoin, which would let you send 1000 messages of up to 1kb each, given the transaction fees.
I'm ignoring some things, but at the moment it seems to be quite the net-win.
Don't forget the costs of relying on authority. First, trust can be broken. Second, if notary is offline or asleep you cannot register your data.
Also: even if you fully trust your notary, it's no guarantee some random people in Japan, Australia or South America will trust him too. Anyone anywhere can verify blockchain, though.
Assume that the notary public needs a 70watt light bulb to function (ignoring food costs, paper, etc). 8 hour day, so about a half kwh. That electricity with a new asic miner would get you about a half bitcoin, which would let you send 1000 messages of up to 1kb each, given the transaction fees.
I'm ignoring some things, but at the moment it seems to be quite the net-win.