Pigeon Pay - SMS Based Offline Payments App

architecture diagram
Initial figma design
local auth - to access app

Inspiration

The inspiration behind PigeonPay was to bridge the gap between digital payment solutions and the offline world. We recognize that not everyone has constant access to the internet, and even in a connected world, there are scenarios where offline transactions could be essential. Moreover, security is paramount when dealing with financial transactions, and we wanted to create a system that ensures the utmost security, even in offline environments.

What it does

PigeonPay is an offline transaction app designed to facilitate financial transactions without the need for an internet connection. Users can send money securely, even when offline, thanks to a public-private key system installed on their devices. Unlike traditional mobile banking apps that rely on internet connectivity, PigeonPay leverages SMS services to execute transactions. To send money, users encrypt a transaction message with the public key, ensuring both security and convenience.

For receiving money, no internet connection is required, making it a versatile solution for various real-world scenarios. PigeonPay is not just a financial payment app; it's a glimpse into a future where seamless offline payments become a reality.

How we built it

Technology Stack:

Security: Pangea's AuthN API for user information storage and Pangea's Vault API for private key management
Backend: Node.js and keysley-codegen
Frontend: Flutter and rsa_encrypt
Communication: Custom SMS service on Android using Kotlin & MQTT

The security of the application is a top priority. Pangea's AuthN API ensures robust user information storage, while the Valut API manages private keys securely. This dual-layer security ensures that only authorized users can execute transactions.

PigeonPay's architecture leverages a blend of modern technologies to achieve its offline functionality. The Node.js backend handles the core transaction processing, while the Flutter frontend provides a user-friendly interface accessible on multiple platforms.

To enable offline communication, we went beyond conventional SMS solutions (Twilio) and developed our own Android SMS service using Kotlin and MQTT. This bespoke approach enhances reliability and security.

Challenges we ran into

Security Integration: Integrating Pangea's APIs securely while adhering to best practices was a complex task. We invested significant effort in ensuring data protection.

Tight Development Timeline: Developing a secure offline transaction app in just one week was a significant challenge. We had to streamline the development process without compromising quality.

Custom SMS Service: Instead of relying on existing SMS services like Twilio, we opted to create our own, which required in-depth knowledge of Android development and MQTT integration.

Cross-Platform Compatibility: Ensuring that PigeonPay works seamlessly on both Android and iOS presented compatibility challenges that we had to overcome.

Accomplishments that we're proud of

Robust Security: We prioritized security at every stage of development, using Pangea's APIs to fortify the application against threats.

Rapid Development: We successfully developed PigeonPay within a week, showcasing our team's commitment and technical prowess.

Custom SMS Service: Creating our own SMS service allowed us to have more control over communication and security, enhancing the app's reliability.

Cross-Platform Compatibility: PigeonPay is accessible on multiple platforms, demonstrating our dedication to user convenience.

What we learned

API Integration: Integrating Pangea APIs securely requires careful planning and meticulous implementation.

SMS service: Developing a custom SMS service provided valuable insights into mobile communication and security.

What's next for Pigeon Pay

Enhanced Features: We plan to add more features, such as transaction history, in-app notifications, and the ability to link bank accounts for seamless fund transfers.

Expanded Platform Support: Expanding to other platforms like the web and desktop will make PigeonPay even more accessible.

Geographic Expansion: PigeonPay has the potential to empower offline transactions worldwide, and we aim to scale its usage in regions with limited internet connectivity.

Security Enhancements: Continual improvements in security, including blockchain integration, will further fortify PigeonPay.

PigeonPay represents a vision where offline transactions are secure, efficient, and accessible to all. We're excited to continue refining and expanding this innovative solution for the benefit of users everywhere.

APK : https://drive.google.com/drive/folders/1aJDsbEluHBumbyYma394puc6L9h58m2v?usp=sharing

Backend Hosted on : https://pigeonpaybackend.onrender.com/

Figma Design link : https://www.figma.com/file/fJPc0rfbfTFuS6jyuIE7gK/PigeonPay?type=design&node-id=0%3A1&mode=design&t=3nPLDbABqC0lscyB-1

Drive Link for APK (present in GitHub release as well): https://drive.google.com/drive/folders/1aJDsbEluHBumbyYma394puc6L9h58m2v?usp=sharing