Offline Credit via Bitchat: How Smartphones Can Process Transactions Without the Internet

Yesterday I published a text about the launch of Bitchat, the new app developed by Jack Dorsey that allows completely offline communication via Bluetooth Low Energy (BLE).

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See more at Bitchat, Offline Push, and the Rebirth of P2P Payments Without Internet

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But the big question that came up and has intrigued many people was
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"How would offline credit work And what if the payer has no balance at the time of the transaction"

The answer lies in a combination of cryptographic signatures embedded security in mobile devices and a delegated credit model all operating without relying on a real time connection.

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📱 Offline credit how does it work in practice

The logic is similar to that of a traditional credit card
Imagine the user already has a pre approved limit of 300 reais for example This limit is defined by a custodial institution such as an exchange or custody platform which signs the authorization and sends the encrypted permission to the user’s device.

This credit limit can even be increased if the user locks a collateral amount through staking as a guarantee.

That authorization data can be stored in two ways

• In local storage, protected with encryption
• Or more securely in the Secure Enclave on iOS or the Trusted Execution Environment on Android

This way even without internet the payment app can check if the user is still within their available limit and authorize the transaction locally.

Now knowing the pre approved limit
how can we lock that value on the user’s device as a maximum spending cap

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🔏 Dual signature and execution once back online

Thanks to technologies like ERC 7702 for delegated signatures and ERC 4337 for programmable smart wallets it is possible to define limits and rules directly inside the wallet

Each offline transaction would contain two layers of signature

1 The payer’s signature confirming the intent to pay
2 The custodian’s signature already embedded in the device validating the authorized credit cap

This transaction is then sent directly to the recipient via Bluetooth using the same offline push concept as Bitchat

Once either of the two devices gets back online the transaction is automatically synchronized and published to the blockchain which finalizes the validation and prevents double spending based on the wallet’s nonce and the programmed rules

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🎯 Simple example Pix offline in action

Let’s say your offline wallet has a 200 reais limit, signed by the custodian and stored on your phone.

You are at a festival with no internet and buy a bottle of water from a street vendor for 8 reais

Your phone checks locally if you have available credit signs the transaction and sends it via Bluetooth to the vendor’s phone which is also offline.

The vendor instantly sees a confirmation saying "transaction received"

Later when either phone reconnects to the internet the transaction is transmitted and settled on the blockchain

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No WiFi No 4G No server
But with security traceability and fraud protection

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💡 The power of Offline Push

Offline push is the foundation of this architecture

Instead of relying on online notifications or servers the data such as transactions messages authentication tokens or signed contracts is transmitted directly between devices via BLE

This logic is perfect for environments with low or no connectivity
such as favelas conflict zones prisons crowded events or disaster areas

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🧠 Final thoughts

A lot of people ask me how I manage to write so much and whether I use GPT

Of course I do
But I am also an erudite thinker and that is clear in the depth and coherence of the ideas I build in my texts

GPT is like an orchestra
But I am the one conducting it

Technology is a tool not a replacement

Just because someone has access to a calculator does not mean they know how to solve differential equations or work with complex numbers 😄

The age of augmented creativity has arrived
And those who understand the idea behind the tools are the ones truly leading the transformation