Bitcoin Forum

I am interested in placing a message into the blockchain for the purpose of timestamping the message (eg adding the hash of a document to the blockchain so that the document can be verified as existing sometime before the timestamp of the block)

I've looked at how btcmsg does it but the comment in this link suggests that btcmsg isn't the right way to do it.

http://bitcoin.stackexchange.com/questions/2616/how-to-decode-messages-embedded-with-btcmsg (http://bitcoin.stackexchange.com/questions/2616/how-to-decode-messages-embedded-with-btcmsg)


Can someone propose how I may best achieve placing a message in the blockchain? I've had some ideas but would like to hear how the pros think it should be done.

I expect flames that 'bitcoin isnt meant for that' - if so please explain the alternative you'd use instead.

I have made a beta implementation of CommitCoin protocol. If you're interested PM me. I'm not ready to make it publicly available just yet but it's fully functional.

An easier alternative if you don't mind paying 0.0005 btc fee is to use hash to address (http://blockexplorer.com/q/hashtoaddress/) utility of blockexplorer to convert the hash of your message to a btc address, and then create a transaction that sends 0 btc to that address. (this way no money is wasted)

You could also just add a public note through blockchain.info

The blockchain.info public note system is not stored in the blokchain, but only on the blockchain.info servers.

You don't benefit from the bitcoin zero-trust network...

You could check out http://www.cryptograffiti.info (http://www.cryptograffiti.info). The idea behind the site is to display transactions which include addresses that have human readable characters in them. The mentioned feature is not jet implemented. The whole thing is in development still. But it does offer a functionality to encode arbitrary text as Bitcoin addresses with relative ease.

why not use twister for it?

thats a blockchain based messaging/twitter/spam service

may also look at bitmessage it has broadcasts

please dont use our bitcoin currency blockchain for it, you pollute it

I'm late to the party here, but Bitcoin Megaphone should suit your needs:

http://bitcoinmegaphone.com

Why not? There's nothing wrong with dust transactions.


Not really, that's server hosted and centralized.

So no other option?

I posted the same question about 1 year ago and I remember that someone suggested that i need to do a RAW transaction in order to store something in the blockchain, but I couldn't find a user-friendly option to do that.

I like the idea of producing a hash/signature from the message and converting it somehow to an address (as previously mentioned).  While its not explicitly adding a message to the block, for the purpose of timestamping/non-repudiation your golden.