Abstract: A method and system for authenticating messages is provided. A message authentication system generates an encrypted message by encrypting with a key a combination of a message and a nonce. The message authentication system generates a message authentication code based on a combination of the message and the nonce modulo a divisor. To decrypt and authenticate the message, the message authentication system generates a decrypted message by decrypting with the key the encrypted message and extracts the message and the nonce. The message authentication system then regenerates a message authentication code based on a combination of the extracted message and the extracted nonce modulo the divisor. The message authentication system then determines whether the regenerated message authentication code matches the original message authentication code. If the codes match, then the integrity and authenticity of the message are verified.

Abstract: A protocol with constant-time complexity solves the problem of private identification of tags in low-cost, large-scale radio frequency identification (RFID) systems—assuming that an adversary has complete control over the communication channel. Each RFID tag has an internal counter, c, and is preloaded with a unique pseudonym, ?, and a secret key, k. A RFID reader attempting to identify and authenticate a tag within its range generates and transmits a random nonce to the RFID tag, which returns a first hash of its current pseudonym and counter, and a second hash that is a function of the secret key. The reader uses the returned data to identify the RFID tag and its secret key by reference to a database and returns other hash values that authenticate the reader to the RFID tag. The most expensive operation that RFID tags are required to perform is a hash function.

Abstract: A protocol with constant-time complexity solves the problem of private identification of tags in low-cost, large-scale radio frequency identification (RFID) systems—assuming that an adversary has complete control over the communication channel. Each RFID tag has an internal counter, c, and is preloaded with a unique pseudonym, ?, and a secret key, k. A RFID reader attempting to identify and authenticate a tag within its range generates and transmits a random nonce to the RFID tag, which returns a first hash of its current pseudonym and counter, and a second hash that is a function of the secret key. The reader uses the returned data to identify the RFID tag and its secret key by reference to a database and returns other hash values that authenticate the reader to the RFID tag. The most expensive operation that RFID tags are required to perform is a hash function.

Abstract: A protocol with constant-time complexity solves the problem of private identification of tags in low-cost, large-scale radio frequency identification (RFID) systems—assuming that an adversary has complete control over the communication channel. Each RFID tag has an internal counter, c, and is preloaded with a unique pseudonym, ?, and a secret key, k. A RFID reader attempting to identify and authenticate a tag within its range generates and transmits a random nonce to the RFID tag, which returns a first hash of its current pseudonym and counter, and a second hash that is a function of the secret key. The reader uses the returned data to identify the RFID tag and its secret key by reference to a database and returns other hash values that authenticate the reader to the RFID tag. The most expensive operation that RFID tags are required to perform is a hash function.