A fast data transfer 
collection system using message 
authentication and contactless RF 
proximity card technology in non-contact storage and retrieval applications. The 
system is generally comprised of Host computers (application computer systems), Target 
radio frequency (RF) terminals, and a plurality of portable Tags ("smart" or "proximity" cards). A Host provides specific application functionality to a Tag holder, with a high degree of protection from fraudulent use. A Target provides control of the RF antenna and resolves collisions between multiple Tags in the 
RF field. A Tag provides reliable, high speed, and well authenticated secure exchanges of data / information with the Host resulting from the use of a custom ASIC design incorporating unique analog and digital circuits, nonvolatile memory, and 
state logic. Each Tag engages in a transaction with the Target in which a sequence of message exchanges allow data to be read(written) from(to) the Tag. These exchanges establish the 
RF communication link, resolve communication collisions with other Tags, authenticate both parties in the transaction, rapidly and robustly 
relay information through the link, and ensure the integrity and incorruptibility of the transaction. The 
system architecture provides capabilities to ensure the integrity of the data transferred thus eliminating the major problem of corrupting data on the card and in the 
system. The architecture and protocol are designed to allow simple and efficient integration of the transaction 
product system into data / 
information processing installations.