MESSAGE AUTHENTICATION IN COMPUTATIONALLY CONSTRAINED ENVIRONMENTS

ABSTRACT:

RFID and Wireless Sensor Networks exemplify computationaly constrained environments, where the compact nature of the components cannot support complex computations or high communication overhead. On the other hand, such components should support security applications such as message integrity, authentication, and time stamping. The latter are efficiently implemented by Hash Message Authentication Codes (HMAC). An approach to implement a compact HMAC by the use of stream ciphering. NMAC and HMAC are proven to be secure as long as the underlying hash function has some reasonable cryptographic strength. RFID and Wireless Sensor Networks pose a need for efficient implementation of MAC. To achieve efficiency, while not sacrificing security, there is a need to evaluate new approaches, while also utilizing any characteristic of the specific implementation of MAC that can enhance efficiency. Two main constraints are considered here: 1) Costs: Wide adoption of RFID is crucially dependent on the price of a tag. This is translated into a limited number of logic gates used in the tag. 2) Power consumption: An RFID tag is operated by a magnetic field radiated from the reader.