Which action BEST reduces the risk of RFID badge cloning for 125kHz EM4100 systems?

• A. Switch to a lower frequency badge with no encryption.
• B. Rely solely on access logs to deter cloning.
• C. Implement a higher frequency RFID system that supports encryption.
• D. Increase badge issuance without changing the technology.

Answer: (C)

The main idea is that stopping badge cloning requires encryption and authentication, not just a newer-looking ID. An EM4100 badge at 125 kHz is a simple, unencrypted tag that broadcasts a static identifier. Because there’s no cryptography, cloning is straightforward: a thief can copy the ID onto another tag and gain access as if they were the legitimate badge.

Upgrading to a higher-frequency RFID system that supports encryption introduces cryptographic keys and an authentication step between the tag and the reader. The reader challenges the tag, and the tag must produce a correct cryptographic response. Without the proper keys, a cloned tag cannot pass the authentication, so cloning becomes far much harder or practically infeasible.

Relying on access logs is too late to prevent a clone from entering, and using a lower-frequency badge with no encryption doesn’t eliminate the vulnerability. Increasing badge issuance without changing the technology merely expands the attack surface, making cloning risks worse, not better.

So, implementing a higher-frequency system that supports encryption best reduces the risk of RFID badge cloning.