This book constitutes the refereed proceedings of the 6th International Workshop Radio Frequency Identification: Security and Privacy Issues. RFIDSec 2010, held in Istanbul, Turkey, in June 2010. The 17 revised full papers presented together with 3 invited talks were carefully reviewed and selected from 47 submissions. The papers focus on approaches to solve security and data-protection issues in advancedcontactless technologies like RFID. Topics addressed are new applications for secure RFID systems, data protection and privacy-enhancing techniques for RFID, cryptographic protocols for RFID, integration of secure RFID systems, resource-efficient implementation of cryptography, attacks on RFID systems, and RFID security hardware.