Ultralightweight RFID Authentication Protocols for Low-Cost Passive RFID Tags

Table 2

EPC classification of RFID tags.

Class	Description
Class 5	Class 5 tags are essentially active readers. They have the ability to communicate with all the EPC standard classes.
Class 4	Class 4 tags are active in nature. They can communicate with the reader and other tags by using peer to peer communication model.
Class 3	Class 3 tags are semi passive tags that can support broadband communication.
Class 2	Class 2 tags are the passive tags with extended functionality such as memory and computational resources.
Class 1/0	Class 1/0 tags are basic passive identity tags with limited resources.