Bitcoin Forum

As the title says, i would like to know how to post a message to blockchain, as a proof, for future consideration

I want to write plain message, not to sign a message via some transaction, not to stamped a document.

Just a plain message, public to anyone via the txid

Thanks in advance

There are multiple ways to encode data into the blockchain. However all of them require burning coins. IMO the easiest and most common method is using an OP_RETURN output. The only downside is that it can only store 80 bytes of data. There are many tutorials of how to do this so google them.

Thanks for your reply

i would like to know if there is a service offering this, already up and running? i was thinking a service like stampd, but this is just for stamping documents.

thanks again

Maybe, I don't know. Google it. This stuff is generally discouraged because it bloats the blockchain and can fill it with useless crap that no one really cares about except a few people.

There is a service that can prove that a document existed by uploading a hash of it to the blockchain. The site is: https://www.proofofexistence.com/

ok, i think i found it...

a service called eternitywall

haven't tried it yet but it looks like the one i want

thanks again

There is also http://cryptograffiti.info/ AFAIK run by HYENA, they also have a BCT thread -> https://bitcointalk.org/index.php?topic=524877.0

Thanks Shorena!

I will give it a try, looks pretty cool.

I already sent my message via the eternitywall, waiting for confirmation.

Isn't that the beauty of bitcoin? That you can do whatever you want within its limits without someone telling you that you cannot do it?

As long as you pay the fees required, I don't see anything wrong with it. Atleast it is much less stupid than the people trying to move 5000 satoshi out of wallets.

There are several methods to encode messages into the blockchain. You could send to addresses with words in it (like Vanitygen), send a transaction with certain amount of money (in hexadecimal) or many other methods. Some websites offer services to encode messages into the bitcoin blockchain. All of the methods require burning some coins because the messages are encoded in a transaction.