[2015-06-30] CD: Payments Firm Backs 'Crazy' Offline Btc Transactions Experiment

[Grand_Voyageur]

Payments Firm Backs 'Crazy' Offline Bitcoin Transactions Experiment

As an Internet-based payment system, most bitcoin transactions today necessitate that users are online or otherwise can print and exchange private keys.

However, Romanian mobile payments provider Netopia mobilPay is now backing a proposal that strives for a middle path. Called OffCoin, the proposal is for a system that allows microSD cards in mobile phones to generate, store, transmit and delete bitcoin private keys.

In effect, OffCoin would be capable of moving digital currency between mobile phones without requiring users to be connected to the Internet or needing to pay the cost of using the bitcoin blockchain. By transacting with NFC, Bluetooth, QR codes or a combination of these technologies, Netopia suggests it can allow users to send and receive bitcoin without paying fees for sending funds over the bitcoin blockchain.

Full story: http://www.coindesk.com/netopia-internet-free-bitcoin-transactions/

[1715698267]

1715698267

[1715698267]

1715698267

[odolvlobo]

It is not explained in the article, but the product is a hardware wallet that deletes a private key once it has transmitted it. If you obtain a private key from one of these wallets, you know that nobody else has it.

Sending bitcoins works like this:

1. Alice generates a private key on her device. She can see the bitcoin address, but not the private key.
2. Alice sends bitcoins to the bitcoin address.
3. Bob uses his device to obtain the private key from Alice's device. The key is automatically removed from Alice's device.
4. Bob imports the private key from his device to his wallet. The key is automatically removed from Bob's device.

[PolarPoint]

How can the receiver verify there is indeed balance in the address exchanged being offline?