Decoding Messages in the Bitcoin Blockchain

By Milly Bitcoin – May 16, 2013

There have been several recent articles about messages placed in the Bitcoin Blockchain. The Blockchain is the database of transactions that is shared among users via peer-2-peer software. In this way a central authority, like a bank, is avoided. Some of the more sensational stories claim “child porn is in the blockchain.” The only thing that can be placed in the blockchain is some text data that needs to be decoded to be understood.

As an example I will show the message placed in the very first block by the inventor of Bitcoin, Satashi Nakamoto.

A web site at BlockExplorer makes looking at the blockchain data easier. For a specific block number just add/b/number. So for the first block the number is “0”: http://blockexplorer.com/b/0

Then click over to the Raw Block Data:

http://blockexplorer.com/rawblock/000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f

In this case the information was added to the “Coinbase” field:

“coinbase”:”04ffff001d0104455468652054696d65732030332f4a616e2f32303039204368616e63656c6c6f72206f6e206272696e6b206f66207

365636f6e64206261696c6f757420666f722062616e6b73″

Then take that string and run through a Hex to ASCII converter such as http://www.dolcevie.com/js/converter.html and you get

???????EThe Times 03/Jan/2009 Chancellor on brink of second bailout for banks

As you can see, most people will never see these messages and it is generally a waste of time to put them in there. Developers are working on patches to prevent the extraneous text as well as methods to eventually “prune” old blocks to reduce the data size of the Blockchain so these messages will eventually be removed form the system. Of course secret messages such as this can be added anywhere, such as comment forms on web sites.