A fast and low-consumption security protocol with optional off-line readers

Aiming at the problem that the speed of search for tags can be significantly slowed down by a large volume of data in a database, we therefore propose a low-consumption communication protocol based on principle of locality on tags. There is a part of data being saved in memory of reader. When search is conducted, a reader searches for information in memory first before searches the database, thus accelerating the speed. Besides, in order to meet the security demand in communication between readers and a back-end database, we propose a protocol that readers can leave the database and be used alone by employing cache mechanism. The protocol cut off the connection between readers and the database after importing in advance the information tasks need into memory, to ensure the security.