What is the technology used in metro cards?

Metro cards, including those used in systems like the **Delhi Metro and [Hyderabad Metro](https://yometro.com/hyderabad-metro-16), generally use contactless smart card technology.** This technology involves:

1. Radio-Frequency Identification (RFID): The cards have an embedded RFID chip and antenna, which allow them to communicate with card readers at the metro gates without physical contact.
2. Near Field Communication (NFC): Some metro cards use NFC, a subset of RFID technology that enables short-range communication between the card and the reader.
3. Microcontroller: The smart card contains a microcontroller that stores and processes data, such as the cardholder’s balance and transaction history.
4. Secure Data Storage: The card’s chip securely stores data to prevent unauthorized access and ensure the integrity of transactions.
5. Encryption: Advanced encryption methods are used to protect the data stored on the card and during communication with the card readers, enhancing security against fraud and tampering.

This technology allows for quick, efficient, and secure access to the metro system, making travel more convenient for passengers.