How to utilize the Bitcoin block chain....

[Mike Cautillo]

Hi to all....I tried posting this elsewhere but it seems no responses. I've heard Andreas A. in one of his last video's refer to someone who put their wedding vows on the Bitcoin block chain and that you can put other things on there as well. Anybody have any information regarding this or is there a company that does this as a service?? I'm interested to find out, what some of the possibilities are??

Thanks.

[CryptAxe]

http://www.cryptograffiti.info/

[BitcoinNewsMagazine]

Bitmain also has an auction process that lets you buy a message to be embedded in the Coinbase script of a mined block see https://forum.bitmain.com/bbs/topics/1203

[coinableS]

What you are referring to and what Andreas was referring to is the OP_RETURN script within bitcoin transactions. A lot of the information within a transaction script is important info that pertains to the transaction, like where the coins came from, where they went, how much was sent, locktime, version, how many inputs and outputs etc. There's also the OP_RETURN which is 40 bytes of arbitrary data. What you decide to put in the those 40 bytes is up to you. So people started hashing documents, songs, birth certificates, wedding vows, etc and stuffed them into the OP_RETURN. The person that hashed the document, can produce the exact same hash years down the road and show that matches the hash of a transaction that was entered on the blockchain thus proving that exact document existed back then.

You can spot an OP_RETURN on a block explorer and viewing the raw transaction.

Example of two outputs below. The first output 'n=0' includes an OP_RETURN script. You can spot it by the script starting with "6a" and you'll also notice there is no value. The second output is an actual spending of an output, there is a value and script does not start with "6a"

Code: Select all

{ "spent":false, "tx_index":112761248, "type":0, "value":0, "n":1, "script":"6a206632393732343036313935653330666664373764326537386331386136333933" }, { "spent":false, "tx_index":112761248, "type":0, "addr":"1NuGysENKQ6yAkmwfhhk1j9JU3M1kSLYtk", "value":213594, "n":2, "script":"76a914f03d9c7cced8b6d2bfb4c433b388266b8e750ef188ac" }

https://blockchain.info/rawtx/180889ec2 ... c23a6324a8

Check out proof of existence for a service that can do this for you.