How can we look at the hidden message in the first block?

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This is the first block, how can I see the message?

'The Times 03/Jan/2009 Chancellor on brink of second bailout for banks'

smatthewenglish

Posted 2016-09-19T20:55:03.760

Reputation: 1 083

related: How can one embed custom data in block headers?

– Murch – 2016-10-14T17:50:16.720

Answers

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Click on the sole transaction in that block (4a5e1e4b...) and click Show scripts & coinbase.

Nate Eldredge

Posted 2016-09-19T20:55:03.760

Reputation: 22 182

how did he do that? I thought OP_RETURN was only added later and that before the only way to do it was to encode data as a fake address in a transaction – smatthewenglish – 2016-09-20T11:55:25.627

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@s.matthew.english: See http://bitcoin.stackexchange.com/questions/20721/what-is-the-format-of-the-coinbase-transaction. Because this is a generation transaction, it has a single input whose script is ignored. The message takes the place of that script.

– Nate Eldredge – 2016-09-20T12:16:49.323

How can I get it through bitcoin-cli, I've tried bitcoin-cli getrawtransaction 4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b true, and return an error telling me that this is the genesis block and transaction whin it can't be retrieved. – an offer can't refuse – 2018-03-27T19:13:10.457

@buzhidao: Yeah, I suspect that you just can't. This is a special case for backward compatibility: the original release of Bitcoin had a bug where the coinbase transaction of the genesis block was not added to the utxo database, thus making it unspendable. Every version since had to keep that behavior; otherwise, if Satoshi ever tried to spend those coins, it would cause a hard fork of the blockchain, as some clients would accept the transaction and others would reject it. – Nate Eldredge – 2018-03-27T23:01:54.123