If you hadn’t read it in the press yet, BIP47 ‘Reusable Payment Codes’ was published in April 2015 by Justus Ranvier. Shortly after publishing, Samourai began work on the first implementation of BIP47 in our alpha wallet. In the next few weeks we will be rolling out this incredible functionality to all our testers. Our alpha program is currently open to anyone who wants to try it out. You can get instant alpha here.









What are payment codes?

Really simply, a payment code is an address that you can safely reuse because each sender uses your code to derive up to 2 billion deposit addresses unique to them.





Why?

There are a few reasons why we decided to devote our limited resources on implementing Reusable Payment Codes

1. Similar benefits as stealth addresses but more robust privacy

Unlike stealth addresses payments sent to a Payment Code are not distinguishable from traditional Bitcoin transactions on the block chain therefore they cannot be identified and cannot be easily censored.

You can publicize your payment code in the same way that you can publicize your email address. Even if everyone knows your payment code, nobody can monitor the blockchain to see how many payments you have received or which transactions are yours. - Justus Ranvier





2. Bitcoin payments can be quicker and less clumsy

Today, if you want to receive payments into your wallet without actively communicating with the sender, for example, posting a donation address on your website or blog, you have a few bad choices.

Reuse a single address - This is really bad. Don’t do it.

This is really bad. Don’t do it. Share your Extended Public Key - This is really bad as well.

Payment Codes change this experience. Once a payment channel is opened you can instantly send bitcoin to recipients without ever needing to communicate with them, and likewise, you can receive payments without your intervention.







So, what’s next?

We’re currently finishing up internal testing and making final UI adjustments before rolling out functionality to our Alpha testers. We’re also reaching out to various organisations and individuals to champion support of BIP 47.

You can help by asking your favourite wallets, exchanges, websites, and services to implement BIP 47 as soon as possible. This is a big win for usability and privacy and we’re proud to be the first to bring Reusable Payment Codes to the market.