by Jamie Holmes
The privacy-focused wallet, Samourai, have introduced a new feature that enables you to send bitcoin payments using standard SMS messages. The update is exciting, as it opens up a whole host of new possibilities for adoption and improves the robustness of the Bitcoin network.
Sending Bitcoin Via SMS
Known as PonyDirect, the proprietary app can send bitcoin without an internet connection, and instead using SMS messages. Moreover, the app sidesteps censorship of the internet, making the SMS option invaluable to those in countries where such restrictions are placed.
Improving the robustness of the Bitcoin network has been eyed for some time now, where the Finnish project Kryptoradio developed a method to accept zero-confirmation transactions entirely offline by utilizing radio waves in 2014. Moreover, the idea of using SMS as a transmission mechanism was touched upon by Pavol Rusnak, CTO of Satoshilabs, in August 2017
Samourai Developer T Dev T told Bitcoin.com: “PonyDirect was developed in-house as a proof-of-concept app with the intention of open sourcing it to be an open invitation for developer participation in the Mule Tools project as a whole.”
The proof-of-concept app is open source, with the code available on GitHub. While you can transmit bitcoin transactions via SMS, you can also relay transactions for your mobile contacts by using your number.
So how does it work? Since an SMS message is limited to 160 characters, several texts are sent with the initial message containing information on the number of messages to be received, the hash ID that must be matched at the end, a batch ID, a sequencing number, and a part of the actual transaction hex.
Another SMS contains a sequencing number, batch ID, and more of the actual transaction hex. Once the series of SMS messages are received from the same incoming number, the whole transaction is reassembled and pushed out to the Bitcoin network. So by dividing the bitcoin transaction as many times as necessary, the relevant information can be sent over SMS and broadcast to the network from there.
Helping those Most in Need
The PonyDirect app is bound to be a great aid to those in developing countries, where mobile penetration has leapfrogged ahead of the developed world. For instance, we can look to the case of MPesa in Kenya as an example, which is a mobile network that provides a financial infrastructure, allowing people to send money using SMS. The Economist Intelligence Unit forecasts that for 2018, we will see an average of 113 mobile subscriptions per 100 people in the world’s 60 biggest markets, with growth mainly driven by India and Sub-Saharan Africa.
T Dev T stated on Twitter that the motivation behind the app is down to the desire to help those in developing countries, and especially those countries where internet is routinely censored:
I don't do this shit to impress hipsters trying to buy brownies using BTC in Shoreditch. I don't do this shit to suck up to whatever Simple Simon CEO happens to be boring me to tears that particular day & needs to respond to VCs w/ROI. This is why i do it: https://t.co/ez5H5MLt54
— TDevD aka "Crud" [No BC.i] (@SamouraiDev) January 19, 2018
The development from the Samourai team follows on from the launch of the Blockstream Satellite, which is another drive to make bitcoin payments uncensorable. By broadcasting real-time blockchain data around the world, those without access to the internet can participate in the decentralized network.
A Wallet that Stays True to Bitcoin
Along with PonyDirect, the features of Samourai wallet make it stand out from the crowd. Privacy-enhancing features in the wallet include sending payments with hops to make transactions less linkable, ability to connect to your own node, support for Tor, and BIP47 reusable payment codes. The reusable payment codes are a neat addition since you can use a QR code again and again without revealing your actual addresses and the funds stored in them.
Another development to keep an eye on is Samourai’s partnership with goTenna, a mesh network that allows texts and GPS messages to be sent even if there is no service:
— Daniela Perdomo (@danielaperdomo) January 19, 2018