Author

Topic: Sending messages to the blockchain with a bitcoin transaction. (Read 1565 times)

sr. member
Activity: 345
Merit: 500
Although i'm not aware of any script that would allow you to do that, i find this article very interesting and detailed:
http://www.righto.com/2014/02/ascii-bernanke-wikileaks-photographs.html

This site reads existing messages on the blockchain:
http://bitcoinstrings.com/

Hope it helps, good luck.
hero member
Activity: 906
Merit: 1034
BTC: the beginning of stake-based public resources

Thanks for this. Is there any application or scripting framework you could point me at to do this so I don't have to write my own software to broadcast a transaction with a message in it.
legendary
Activity: 3472
Merit: 4801
It's not supported by the Bitcoin-Qt command line interface.

You need to build a raw transaction using the OP_RETURN op code in an output with the message that you want.

Then you can use signrawtransaction and send rawtransaction to send the transaction and hope that a miner will confirm it for you.

Thanks for this; can you point me somewhere where I can read up on how to do this?

Transaction structure:
https://en.bitcoin.it/wiki/Transactions

Script Op codes:
https://en.bitcoin.it/wiki/Script
hero member
Activity: 906
Merit: 1034
BTC: the beginning of stake-based public resources
It's not supported by the Bitcoin-Qt command line interface.

You need to build a raw transaction using the OP_RETURN op code in an output with the message that you want.

Then you can use signrawtransaction and send rawtransaction to send the transaction and hope that a miner will confirm it for you.

Thanks for this; can you point me somewhere where I can read up on how to do this?
legendary
Activity: 3472
Merit: 4801
I am sure you can write a short message in a transaction using blockchain.info wallet. You may not want to use their online wallet, that's how I do it.

Blockchain.info does not put messages in the transactions.

They just store messages in their own database and make them available on their website.  They are not broadcast with the transaction, they are not stored in the blockchain, and they are not visible to any other wallets.
cp1
hero member
Activity: 616
Merit: 500
Stop using branwallets
You can also encode a message as the address, but that won't associate the message with a "real" transaction.
hero member
Activity: 672
Merit: 500
I am sure you can write a short message in a transaction using blockchain.info wallet. You may not want to use their online wallet, that's how I do it.

Edit: DannyHamilton has informed me that the message attached with the transaction written by blockchain.info wallet is NOT broadcasted to the blockchain and no other client can read the message. Thanks DH!
legendary
Activity: 3472
Merit: 4801
Does anyone know if there is a way to write the message from the Bitcoin-QT command line interface then?

It's not supported by the Bitcoin-Qt command line interface.

You need to build a raw transaction using the OP_RETURN op code in an output with the message that you want.

Then you can use signrawtransaction and send rawtransaction to send the transaction and hope that a miner will confirm it for you.
hero member
Activity: 906
Merit: 1034
BTC: the beginning of stake-based public resources
Does anyone know if there is a way to write the message from the Bitcoin-QT command line interface then?
legendary
Activity: 1876
Merit: 1475
It is possible, but as far as I know UI clients normally don't write or read that message.

You can read more about it here:
http://www.proofofexistence.com/about
hero member
Activity: 906
Merit: 1034
BTC: the beginning of stake-based public resources
I thought that one could optionally send a short message (40 bytes) to be written to the blockchain with a valid transaction.

If it's possible how do I do this?

Jump to: