Over the last two decades, digital payments have become an integral part of our everyday lives. Today, we can send money across borders, purchase goods using mobile wallets, and transfer digital assets without necessarily relying on traditional financial intermediaries. Despite these advances, one fundamental challenge remains: accessibility.
For people living in rural communities, traders operating in areas with unreliable mobile networks, and businesses experiencing network congestion, completing a digital payment can become unexpectedly difficult. In these situations, the problem is not necessarily access to a bank account or a digital wallet. Rather, it is the inability to connect to the infrastructure required to authorize, verify, or complete a transaction.
This challenge has not gone unnoticed. It has attracted interest across both traditional finance (TradFi) and decentralized finance (DeFi). Research into offline payment protocols and blockchain-based payment systems is exploring new ways to make digital payments more resilient when connectivity is unavailable.
Within the Web3 ecosystem, developers and researchers are exploring how digital transactions can be initiated, authorized, and exchanged without requiring a constant internet connection.
In this article, we'll explore emerging approaches to offline payments in DeFi. I'll also introduce PAT (Primitive Airborne Transaction), my contribution to this evolving field, which I had intended to submit to Colosseum's World Fair hackathon.
Innovations and Approaches to Offline Payments in Web3
1. Solana: Fast Payments, QR Codes, and Offline Signing
Solana is particularly interesting in this discussion because it combines a high-performance blockchain with a payment ecosystem designed for consumer applications.
From exploring its documentation, I learned that Solana supports offline and multi-party transaction signing, including the preparation of transaction messages, independent signatures, transaction validity, and eventual submission. For instance, a transaction can be prepared and signed independently of the device that eventually broadcasts it. This was one of the reasons I chose to build PAT on Solana.
However, Solana Pay's standard QR-based payment flow is not itself a complete offline payment solution. QR codes solve a communication and user-interface problem. They do not eliminate the need to validate transaction state or prevent a payer from attempting to spend the same funds more than once.
- Bitcoin: Offline Transaction Authorization
In June 2026, researchers presented Offline Bitcoin: An Air-Gapped Protocol for Trustless Bitcoin Transactions at the IEEE International Conference on Blockchain and Cryptocurrency.
The research describes a protocol and application for making Bitcoin payments using devices without internet access. It leverages Bitcoin's Taproot capabilities and QR codes to exchange payment information between offline and online devices without requiring the offline device to connect to the internet. The intended receiver can claim the funds using a secret, while the sender can recover them after a configurable timeout if the receiver does not act.
The fundamental difficulty with offline blockchain payments is that disconnected devices cannot query the latest blockchain state. This creates challenges involving transaction validity, forgery, and double-spending.
This brings us to an important question:
How can a system preserve the accessibility of offline payments without compromising the integrity of digital money?
It is within this context that I began building PAT.
PAT (Primitive Airborne Transaction)
Although I did not get to submit PAT to Colosseum's World Fair hackathon, I built Primitive Airborne Transaction, a Solana-based project exploring how digital payment workflows can operate during periods of intermittent connectivity.
The underlying idea is simple:
Reserve while connected. Spend while disconnected. Settle when reconnected.
Step 1: Connect your wallet.
The sender connects a compatible Solana wallet to PAT while online.
Step 2: Reserve funds for offline spending.
While connected, the sender reserves funds for a future payment. This establishes the transaction's context before the sender goes offline.
Step 3: Authorize the payment offline.
When the sender wants to pay, PAT generates a payment authorization tied to the intended receiver's wallet address. This authorization is represented by a cryptographic signature, which can be shared through a QR code or copied for transfer.
The authorization is valid for a limited period. This helps define how long the payment request can be used.
Step 4: Submit the payment for settlement.
The merchant receives the authorization and, when connected to the internet, scans the QR code or enters the provided signature and initiates settlement on Solana.
The blockchain then checks the relevant transaction conditions before the payment can be completed.
This means the payment authorization can be exchanged without requiring the sender to have an active internet connection at that moment, while the merchant can submit the transaction when connectivity is available.
PAT is an amalgamation of multiple ideas:
- Solana-based reservation state
- Cryptographic authorization
- Local persistence
- QR-based exchange
- Deferred settlement
The goal is to address the gap that emerges when the normal online payment workflow is interrupted. However, the current prototype still has shortcomings, particularly in user experience and operational reliability, that need to be addressed.
You can explore the application here:
GitHub: Hilda-Enyioko/pat
While we share ideas and contribute to financial accessibility, a key question is ask is:
Can the concept behind PAT be replicated in TradFi systems?
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