Ff is a family of lightweight and privacy-preserving authentication protocols for RFID-systems.
Contrary to related work, Ff offers user-adjustable authentication and privacy without requiring a complex
cryptographic hash function or non-volatile state on the tag. At the core of Ff is a lightweight keyed hash
function that allows the reader to identify and authenticate a tag by iterative elimination of the entries in
its database through a few rounds of verifications. The security of Ff is analyzed against algebraic and
statistical attacks, attacks based on the LPN technique, and also with respect to recently highlighted SATsolving
approaches. The feasibility of the scheme is discussed through an estimation of the hardware cost
and of the protocol performance based on a specific instance of the Ff family.
