The Fudan 1K​ (model FM11RF08) is a 13.56 MHz contactless RFID chip​ developed by Shanghai Fudan Microelectronics. It is a fully compatible, cost-effective clone of the MIFARE Classic 1K (S50)​ chip, widely used in access control, transportation, and payment systems in China and globally.

1. Core Definition

The Fudan 1K is a high-frequency (HF) read/write IC​ operating at 13.56 MHz. It is designed as a drop-in replacement​ for the NXP MIFARE Classic 1K, offering identical memory structure, command set, and security mechanisms (proprietary Crypto1 encryption), allowing it to work seamlessly with existing MIFARE readers and infrastructure.

2. Key Technical Specifications

The chip includes an integrated RF interface and requires no external power source, operating entirely from the energy harvested from the reader's field.

3. Protocol & Compatibility

• MIFARE Classic 1K (S50) Compatible: Fully emulates the command set and memory layout of the original NXP chip. Systems configured for MIFARE Classic can read/write Fudan 1K cards without any firmware changes.
• ISO/IEC 14443-A: Compliant with the international standard for proximity cards.

4. Common Applications

• Access Control Systems: Office buildings, residential complexes (often as CR80 cards or key fobs).
• Transportation & Payment: Bus cards, metro tickets, electronic toll collection (ETC).
• Campus/Enterprise Cards: "All-in-one" cards for ID, meal payment, and library access.
• Loyalty & Stored Value: Low-cost prepaid card systems.

5. Security Note

Like MIFARE Classic, the Fudan 1K uses the Crypto1 cipher, which is considered vulnerable​ to cryptographic attacks (e.g., via tools like Proxmark3). It is suitable for low-to-medium security applications but should not be used for high-security financial transactions without additional protection layers.

In summary, the Fudan 1K is a popular, low-cost alternative to MIFARE Classic 1K, offering the same functionality for mass-market RFID applications where high security is not the primary concern.