Radio Frequency Identification (RFID) technology has been studied for several years. Supply chain management is one of the most significant fields that employ this novel technology. RFID-based EPCglobal network is a distributed inter-domain system, which enables every partner within the supply chain to share information with each other. However, no detailed security specification has been developed in EPCglobal standard, therefore a security mechanism is needed to solve the inter-domain information sharing issues between entities that have business relationship. In this paper, we examine the security threats, requirements and solutions for EPCglobal network from the information security perspective, with a focus on the authentication mechanism. We propose a security platform and a X.509 public key infrastructure (PKI) based EPCglobal certificate hierarchical model. The model enables a fine-grained authentication framework to secure the inter-domain EPCglobal supply network.