Memories 2 Btc

Motivation

Experimenting a bit with Blockchains and specifically Bitcoin, I found out about a way to write a short hex-string into an unspendable transaction. This is quite cool, because typically you cannot put any sort of actual data into the Bitcoin blockchain, just transactions of money.

However, with this you can simply write a UTF-8 hex encoding of a short string into the chain for a small amount of Bitcoins, and the best part, most blockchain explorers even decode this message back to UTF-8 when displaying the transaction. Thus, the idea of using this for a modern version of the love-lock on bridges arose. An unmodifiable, short piece of text that is as close to digital eternity, as it gets.

Development

The idea was to create a certificate for your transaction, which includes all data about it, and can be a nice gift or something you can put up for display. As I didn't want to enter all the data by hand, I initially created an HTML template for the design of the certificate. A small Python script uses an open source API of the Bitcoin blockchain to retrieve all data for a given transaction, then extracts the relevant parts and fills it into the template.

Using HTML and the default browser print turned out to be very cumbersome, imprecise and highly machine dependent. So I decided to rework it using the reportlab Python package. This directly creates a PDF with the formats, styles, fonts etc defined in a Python script. Now all it takes is a Python script execution and the final PDF is created.

Results

I made a small Etsy shop where you can order a message, which I will write to the blockchain and create your own certificate using my script. I will then print it professionally on a special high quality paper with a golden ribbon and put into a frame if you want to.

Technologies