FINANCE

Smart Multi-Card Digital Payment Solution.

Project Overview

Developed a next-generation smart card capable of storing and managing 8–10 digitized debit/credit cards, supporting major payment schemes like Visa, Mastercard, and Amex. The user can select a desired card via a mobile app and perform transactions via NFC or swipe, with secure OTA provisioning and lifecycle management of stored cards.

HARDWARE | FIRMWARE | MOBILE/WEB APPS

Client Requirement & Objectives

Multi-Card Storage & Support

The smart card must be capable of storing up to 10 physical debit/credit cards digitally, supporting various card types and global payment schemes.

Mobile App-Driven Provisioning

Users should link cards to the app, which fetches digitized versions from the bank servers and securely transmits them to the card.

Secure Card Management

The system should support adding and deleting cards, including automatic handling of expired cards and dynamic selection during payment.

Independent Operation

Once provisioned, the card should be operable independently of the mobile app, allowing both NFC-based and traditional swipe-based payments.

System Design & Build

Ultra-Slim Embedded Architecture

Engineered a compact PCB layout and embedded system design to match standard credit card dimensions, housing NFC, magstripe, display, and microcontroller units.

Secure Communication Protocols

Implemented end-to-end encryption between mobile app, backend server, and smart card using secure BLE, TLS protocols, and tokenized card data.

User Interface & Selection

Designed a minimal, on-card display and capacitive touch system allowing users to select the card in real-time before presenting it to a terminal.

Power Optimization & OTA

Incorporated low-power chipsets and dynamic sleep-wake cycles, while enabling secure over-the-air (OTA) updates with minimal energy consumption

Key Challenges & Solutions

Physical Size & Integration Constraints

Fitting all electronic components, battery, and antenna in the thin profile of a traditional card was addressed through multi-layer flexible PCB design and component miniaturization.

Power Efficiency

Achieved 1–2 months of battery life using ultra-low-power BLE modes, display timers, and energy-efficient NFC activation only during transactions.

Secure Provisioning Pipeline

Built a secure backend and mobile app architecture with certificate pinning, tokenized communication, and secure element storage on the card for safe card download and deletion.

Reliable OTA Updates in Low Power Mode

Developed a lightweight OTA protocol capable of updating firmware and configurations within strict battery constraints, without degrading user experience or security.