Bitcoin Forum

Hi all.

Occasionally there will be a transaction on the Bitcoin network with a ScriptPubKey that isn't a normal address, and indeed could be redeemed by anyone with enough cleverness to construct a matching ScriptSig.

As a matter of culture, is it considered incorrect or impolite to redeem such an output if you don't know who sent it or where it's from? Is it considered theft? Or merely treasure-hunting?

If the transaction is clearly a can-be-redeemed-by-anybody, or clearly a puzzle that anybody (given some effort) could solve, then I think the point is the "game" if you will, to see who could redeem it first. I, for instance, submitted transaction 09f691b2263260e71f363d1db51ff3100d285956a40cc0e4f8c8c2c4a80559b1 (https://blockchain.info/tx/09f691b2263260e71f363d1db51ff3100d285956a40cc0e4f8c8c2c4a80559b1) to redeem an output that was clearly a puzzle, since it involved finding data that hashed to the genesis block hash (which is publicly accessible). I don't know who put that "bounty" into the chain, but I don't see how whomever put that transaction out there could have been meaning it as anything other than as a puzzle for people to try to complete and win the coins.

But if you found a transaction that might just be buggy somehow, I think it'd be a bit murkier. It may be hard to determine who actually sent it and what they were intending unless they specifically post here or something asking for help. But I'd expect that it'd be similar to finding cash lying in the street. You probably ought to make a reasonable effort to find the owner (where what counts as "reasonable" may depend on how much cash it is), but if it's in an envelope labeled "gift for anybody who wants it" then it's clearly yours.

If you can claim it, claim it.

I don't quite understand how someone can just claim a transaction. Does this apply to the "Strange Transactions" under Block Chain?

The short answer to your question is "yes".

You see, any transaction output has a ScriptPubKey field - a script indicating the conditions a later transaction must meet to spend that output's BTC.

In 99.999% of cases, the script just says "the spender must sign their transaction with the private key whose public key hashes to {ADDRESS}". In other words, it provides an address and requires that the spender prove that they own the address.

However, it's totally legal to require something else instead, and in a few cases, that's what someone's done, and what they've required is something I can provide, even though I don't know them or why they made a transaction like that.

I'm asking about those cases.