Bit-oriented generators for wireless sensor networks and low cost RFID Transponders

Abstract

Wireless Sensor Network (WSN) nodes and passive RFID transponders (tags) have severe constraints in computing power and hence offer particular challenges in the provision of e-Security. Passive RFID tags are at the lowest end of the spectrum in the family of devices with constrained computing power and memory. New approaches, differing from the traditional cryptosystems such as RSA or Diffie-Hellman, focusing on reducing complexity while being capable of providing an adequate level of security, are required for such devices. The use of one time codes is particularly appropriate as they guarantee perfect security and offer simple implementation. However, a significant hurdle to using one time codes is the size of the keys required for encrypting data. The task is further complicated by the need to have a purely randomly generated key. This paper explores lightweight security methods based on bit oriented generators and one time codes, with the capability of meeting the constraints of resource limited devices and the demands for security services. The paper suggests as a lightweight security option, the unique capabilities and suitability of the shrinking generator for WSN nodes and low cost RFID tags.