Privacy Protection for RFID's -- Hidden Subset Identifiers
      Jacek Cichon and Marek Klonowski and Miroslaw Kutylowski
                    Wroclaw University of Technology


We propose  very simple and cheap but nevertheless effective
protection against privacy threats for RFID-tags.
For the hidden subset RFID-tags proposed in this paper, the
ID string presented by an~RFID-tag evolves rapidly; it is is 
not the bit value that enables one to recognize a~tag.
Instead, a reader detects some invariant properties that are hard
to be recognized by a curious illegitimate reader.
The solution is not based on any cryptographic primitive,
it relies only on properties of random sets and on linear 
mappings between vector spaces. The solution proposed is  
well suited for low-end devices.

Keywords: RFID-tag, privacy, unlinkability, dynamic ID