Security Analysis of MIFARE Classic 1k NFC 

Abstract: This study presents a security analysis of the MIFARE Classic 1K Near Field Communication (NFC) card, one of the most widely deployed contactless smart card technologies used in access control. The research focuses on evaluating the practical security of the MIFARE Classic 1K architecture and examining the effectiveness of cloning and authentication bypass techniques using modern RFID penetration testing tools. The MIFARE Classic 1K card operates at 13.56 MHz according to the ISO/IEC 14443 Type-A standard and contains 1024 bytes of EEPROM memory organized into 16 sectors. Each sector is protected through a dual-key authentication mechanism consisting of Key A and Key B, while access permissions are controlled through configurable access bits. In this study, a practical penetration testing approach was employed using the Proxmark3 platform running the Iceman firmware branch. Proxmark3 is an open-source RFID and NFC research platform capable of reading, analyzing, emulating, and cloning various contactless smart cards. The platform was utilized to obtain a complete memory dump of a target MIFARE Classic 1K card, including sector data and authentication keys. The extracted dump, authentication keys, modified access configurations, and card identifier information were subsequently transferred to a configurable UID (CUID) card, a MIFARE Classic-compatible clone that permits modification of the normally read-only UID field. The cloned card was then introduced into a controlled testing environment to assess its operational compatibility with the original system. Experimental results demonstrated that the cloned card functioned identically to the original card and was successfully recognized by the test platform. The findings indicate that the security of MIFARE Classic 1K cards remains vulnerable to practical cloning attacks when sufficient access to card data and authentication keys is achieved. The study highlights that encryption of stored data alone may not provide adequate protection against unauthorized duplication, particularly when weaknesses in legacy authentication mechanisms can be exploited. As a result, systems relying solely on MIFARE Classic technology may face elevated risks of credential replication, unauthorized access, and identity spoofing. Based on these observations, the study recommends the adoption of more secure NFC technologies, such as modern cryptographic smart cards with stronger authentication protocols, whenever feasible.

Access Bit Editor, Modifier and Calculator

Results:

• The test has been successfully cloned.

• After inserting the clone card to test bench, it has worked exactly as test card.

• The access bits of all sector has obtained and successfully alter based on acceptance criteria.

• MIFARE Classic 1k Card bear a significant level of risk even after encrypt all the data block.

• Therefore, it is recommended to avoid MIFARE classic if alternatives are available.