A Quorum System for Distributing RFID Tags

Recently, the applications of radio frequency identification (RFID) technology have been increasingly used in various fields that need automatic identification. RFID is an alternative to the barcode due to its advantages in providing accurate information, ease of control and reduced labour costs. However researchers have reported security and privacy issues with RFID technology that can make it vulnerable to many threats. To counter such threats, several RFID based authentication schemes have been proposed. Secret sharing schemes have been proposed to control key management in RFID systems. Elliptic curve cryptography (ECC) has also been applied within RFID systems to add security and provide stability properties. However, most RFID based schemes do not focus on Multi-tag RFID systems. This paper is an attempt to develop an RFID system that allows two or more RFID tags to be authenticated within an RFID reader by using a combination of the ElGamal threshold scheme and elliptic curve cryptography. With threshold ElGamal, the tag's secret information is split by using Shamir secret sharing among n tags with n secret shares such that any k tags can reconstruct and decrypt the secret information. The elliptic curve version of ElGamal is used in the implementation to reduce the storage of the Shamir secret shares in RFID tags. The security of the scheme is based on the security properties of the Shamir secret sharing scheme and elliptic curve cryptography (ECC).