Transact Bitcoin with no internet

3

An issue I find when I travel is that I would like to visit a cafe that accepts Bitcoin but because I am abroad I usually don't have an internet connection on my phone. I could use WiFi but what is the best way to transact Bitcoin without internet at a point of sale? i.e low value transactions.

Kharoof

Posted 2015-12-27T17:27:29.493

Reputation: 203

Answers

4

To transact in Bitcoin you will need to broadcast the transaction to the Bitcoin network. At this time an internet connection on your phone is going to be a requirement, a wifi hotspot at the cafe is all you need.

In theory there are other ways to get the transaction to the network for example sending the transaction directly from your phone to the point of sale system using NFC or Bluetooth. Search bitcoin over NFC or Bluetooth and you can read about these.

Sending the transaction over SMS is also a possibility in the future

Edit: As pointed out Bluetooth and NFC support is already built into some wallets. See Bitcoin Wallet or Airbitz for example.

Dustin Butler

Posted 2015-12-27T17:27:29.493

Reputation: 461

2Bitcoin Wallet on Android at least already supports Bluetooth payments. I think some others do too (and NFC). (In some tests it actually didn't work for me, but Bluetooth is quite quirky on my device.) Anyway as far as I understand they're using one of the Payment Protocol BIPs, so it should be compatible among different wallets. The gust is that the payer (without internet connection) send the signed transaction to the payee over Bluetooth and then the payee broadcasts it over the Bitcoin network. Upvote if you alter your answer to include BT supported today. – Jannes – 2015-12-27T21:20:08.567

-1

If you have a wallet with some BTC in it, you can simply give somebody else the private key associated with that address (offline) and you will have effectively transferred control of them over to that person.

user10405

Posted 2015-12-27T17:27:29.493

Reputation: 94

1This won't work for buying coffee while on holidays. – Kharoof – 2015-12-30T20:22:58.223

1As long as they trust you this would work example: giving a friend a paper wallet for a gift or payment. You have transferred control to them but you still retain control until they move the coins. – Dustin Butler – 2015-12-31T00:35:36.997