Noisy Cryptographic Protocols for Low-Cost RFID Tags

Considering some passive eavesdropper, the feasibility of exchanging some secret data between an RFID tag and its reader through public discussion is established. No key distribution is required by our solution; the tag and the reader do not have to share any common data to form a confidential channel. For this, a natural phenomenon-the inherent noise on their communication link-is exploited. Classical protocols, consisting after an initialization step in three phases called advantage distillation, information reconciliation and privacy amplification, are then adapted to these highly constrained devices. First, the canvas of our study is presented. Next, the advantage distillation phase is discussed. Then, Brassard and Salvail´s Cascade protocol is proved to be modifiable so as to reduce the hardware implementation cost while still maintaining adequate correction rate and tolerable leaked information during the reconciliation phase. Finally, as for the privacy amplification phase, the work on low-cost universal hash functions from Yuumlksel is pointed out, achieving to allege that public discussion under noisy environment might be an interesting possibility for low cost RFID tags