Soft blocking: flexible blocker tags on the cheap

A “blocker” tag is a form of privacy-enhancing radio-frequency identification (RFID) tag. It operates by interfering with the protocol in which a reader communicates individually with other RFID tags. While inexpensive to manufacture in quantity, blockers are nonetheless specialpurpose devices, and thus introduce level of complexity that may pose an obstacle to their deployment. We propose a variant on the blocker concept that we call soft blocking. This involves software (or firmware) modules that offer a different balance of characteristics than ordinary blockers. Soft blocking offers somewhat weaker privacy enforcement that is essentially voluntary or internally auditable (much like P3P). It has the significant advantage, however, of relying on standard (or very slightly modified) RFID tags. Additionally, soft blocking also offers the possibility of flexible privacy policies in which partial or scrubbed data is revealed about “private” tags, in lieu of the all-or-no...

• Type: Conference
• Year: 2004
• Where: WPES
• Authors: Ari Juels, John G. Brainard
• Keywords: Privacy-enhancing Radio-frequency Identification, RFID Tags, Soft Blocking, WPES 2004