Cloning Mifare Classic Cards via Proxmark3

# Summary MIFARE Classic cards, widely used in access control and transit systems despite their cryptographic vulnerabilities since 2008, can be cloned using a Proxmark3 RFID research device. The Proxmark3—available as an official $300 RDV4 model or cheaper $20-60 clones—is superior to other tools because it can execute the full attack chain (dictionary, darkside, nested, and hardnested attacks) using computer processing power to bypass the cards' outdated CRYPTO-1 encryption. The author used this method to create replacement access cards for their apartment building rather than paying inflated replacement fees.