A Twitter user has claimed that he successfully carried out a bitcoin transaction over the weekend without mobile network or internet connection. In a thread on Twitter, Coinsure wrote a step-by-step account of how he performed the transaction using goTenna and Samourai Wallet in Auckland, New Zealand where he lives.

Experiment Setup

goTenna is a company that sells special devices that create ‘mesh networks’, which allow users to use text and GPS functions without cellular service on their phones by essentially creating their own signal. According to the company, its devices cover a maximum range of 6.4 km in open spaces. Stating that his original aim was to know if he could send a transaction covering 19.2 km using 4 goTennas, Coinsure used Google maps to determine a route that connected high ground points as close to 6.4km apart as possible.

According to Coinsure, the only equipment he used were 4 goTenna devices, a basic android smartphone with no mobile or Wi-Fi connection, clothes pegs, scrim and cords to cover the relay goTennas.

He says that he set up camouflaged relay stations which enabled passive reception of any messages broadcast within range and passed them to other goTennas. The process involved using the android phone with no network signal to broadcast a signed bitcoin transaction generated in the Samourai Wallet as a goTenna message to his girlfriend’s phone which was connected to a cellular network and goTenna. On receiving the transaction through goTenna, her phone relayed it over the internet and the balance would be credited if the transaction was confirmed.

Successful Demonstration

Three transactions were reportedly attempted. The first two, a goTenna to goTenna from One Tree Hill to Mt Albert with a distance of 5.61km and the second from Mt Albert on his girlfriend’s phone to One Tree Hill were successful. A total of 12.67km (7.06km and 5.61km) was covered in this case. The third transaction which was planned for Parkinson Lookout did not go through. He as ascribed this to the possible distance of 7.15km or an app crash experienced by his girlfriend. Other transactions attempted on the way back were also unsuccessful.

He revealed that only one transaction can be sent offline as there is usually a need to reconcile transactions so as to avoid an accidental double spend.