Comment by ryan-c | Hacker News Reader

Comment by ryan-c | Hacker News Reader

> Remember that time when you tried to transfer your life savings from one bank account to another for a small fee, but swapped the fee field with the total transfer amount field, and ended up losing all your life savings? Of course you don't. There are safeguards to catch and prevent these kinds of errors. > > But this is a common occurrence in Bitcoin-land.

This mistake is difficult, if not impossible, to make with standard Bitcoin software. The fee field is usually pre-filled and somewhat tricky to change, and newer versions of bitcoin-core will block transactions like this as obviously wrong. It should also be noted the bitcoin fees are implicit in transactions - a transaction will have some amount of funds going in, and some amount going out, and anything left over is the fee. Usually these types of mistakes actually happen when someone manually crafts a transaction and forgets that they need to make a change output for themselves.

It is obviously still possible to create transactions like this, but it currently requires using advanced interfaces and deliberately bypassing safety measures.

All types of costly mistakes happen in non-bitcoin land too: Deutsche Bank accidentally transfers $6bn to hedge fund client (http://www.theguardian.com/business/2015/oct/20/deutsche-ban...)

...as long as humans are involved in transactions (by writing software if anything), human errors seem to be bound to happen.

The diference with Bitcoin-land is right there in the article: "and recovered one day later".

Miners will typically return obviously erroneous transactions to keep bitcoin users in good faith. It's happened numerous times, including this week.

But they don't have to and they aren't going to be held accountable if they don't.

The author(s) theory is that the mistake was made by a bitcoin laundering script.

I'm surprised that this even happens. It's so involved to make a transaction yourself. It's not like leaving your keys on the kitchen counter. It's more like building a house and forgetting to add a door

Basically, any client which can speak the protocol can send transactions. Normal human consumers use it via clients like multbit-hd (on Desktop) or any of the online wallets, which of course don't allow this mistake to happen, as they calculate the fee for you (online wallets add their commission as well).

But as the article says, likely it happened via a script. But its a very costly mistake. I hope we know the real cause of it.

Overall, I like the depth the article has gone into. But I don't agree with this sentence:

the kind of script that swaps arguments by mistake may be the kind of script that does not write its keys out to a database, so the private keys may be long gone

I think the article got it wrong. How can the private key be lost (and also logged to DB!)? The 291+ btc would have come from some public key. If that that public key has got more btc attached to it, then the owner surely still has the private key. Also even if its zero value now. The wallet (public-key) from which the money came, would still exist, and private key still there somewhere.

So the miner can return the extra BTC to the same public key. Am I missing something?

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