Educational Byte: Exploring Offline Cryptocurrency Transactions

Currently, the use of cryptocurrencies depends on two main things: electricity and the Internet. In general, you can’t send or receive coins without, at least, being connected through a previously charged mobile phone. So, can we conclude that offline transactions with cryptocurrencies are impossible? Not really. There are functional ways, some of them easier than others.

Over the years, several projects and proposals have been shared to do exactly that. Sending cryptos via radio, Near-Field Communication (NFC), mesh networks (local networks built with users’ nodes), SMS, and satellites have been tested with more or less success. Let’s check some of these methods.

Offline cryptocurrency with dedicated devices

This is the more expensive way to do offline crypto transactions because it requires extra equipment. NFC devices, mesh networks, and satellite communication can be included in this category. Remarkable players in the sector are the firms GoTenna and Blockstream, which offer their own devices to make this kind of transaction.

Blockstream operates a global Bitcoin satellite network, broadcasting the blockchain worldwide, even in areas lacking reliable Internet. With four satellites covering six zones, it facilitates uninterrupted access to Bitcoin data. Although some remote areas are uncovered, most of the world, including America, Europe, Africa, Asia, and Oceania, can access ledger information offline through a small antenna and USB receiver setup costing $500.

For its part, GoTenna (in collaboration with Blockstream) introduced a Mesh Network enabling offline crypto transactions. Each device/node was priced at $200, but they’re sold out for the moment. GoTenna's nodes connect independently, allowing users to share messages and conduct Bitcoin transactions via mobile without the Internet.

The TxTenna app was developed with Blockstream and Samourai Wallet to work with the mesh network. It enhances privacy, and security, and bypasses potential local censorship by making offline Bitcoin transactions among GoTenna users.

In addition, companies like GK8 are offering specialized devices for businesses. Their Cold Vault, with its own plug-and-play platform, promises high security with a patented unidirectional solution for crypto transactions without the Internet. The price is yet to be published, though.

Offline cryptocurrency via SMS

Several wallets offered this service in the past, but now they’re mostly discontinued. The premise was, mainly, sending a link to claim some coins. Another service of this style still in operation is Machankura / 8333.mobi, developed by South African coder Kgothatso Ngako and available for seven African countries.

Targeting users in Africa with feature phones, it addresses the limited penetration of Internet-enabled smartphones in the region. Users dial a number, register with a 5-digit PIN, and access menus for learning about Bitcoin, sending, and receiving. Integrated with Bitrefill and supporting Lightning Network transactions, it transforms phone numbers into Lightning addresses.

They also partnered with Azteco, a service of Bitcoin vouchers. Individuals lacking Internet-connected devices can claim Bitcoin through Azteco without accessing their website. Users simply dial a USSD code and include the Azteco Voucher's "reference code" located at the voucher's bottom.

Offline transactions in Obyte + Other Coins

A common characteristic among the projects mentioned above is that they mainly focus on Bitcoin transactions, not including other tokens. This is different from the Obyte Wallet and its Textcoins feature. You can send offline any token previously sent to your wallet, even one that you just created yourself.

It’s also easy and inexpensive, without requiring any extra equipment. A textcoin is like a paper wallet, built with 12 secret words that could contain any amount, in any Obyte-compatible and public token. The path to creating one through the wallet app is quite short: Send Tab – [Select Token and Amount] – Share Via Message.

The app will generate 12 secret words with that amount, and that’s it. You can share it with anyone via text, digitally or physically. Share it in Morse code if you want! However, to receive it and verify its legitimacy, it’s important to have an Internet connection, even for some moments.

Besides, if the recipient rejects or loses your gift, you still can recover it in your wallet. Just go to the History Tab, find your transaction in that token, and click on “Claim Back.” As for the available tokens to use, you can check a wide variety in the Counterstake Bridge. This is a user-friendly platform that imports and exports cryptocurrencies into and out of the Obyte ecosystem. For instance, you can use several stablecoins (USDC, USDT…), ETH, WBTC, BNB, MATIC, and more.

The recipient doesn’t need to have an Obyte wallet initially, but they’ll need one to claim the funds eventually. After claiming the funds in their own wallet, the recipient can exchange them for fiat and other coins using the Counterstake Bridge and/or the crypto exchanges Oswap.io (decentralized), Kaiserex, CoinSpot, and Bittrex Global (centralized). You can start using textcoins now!