Patent attributes
An access card may store an encrypted operation key and a key used to read the encrypted operation key from the access card. The encrypted operation key and the key may be based on a unique identifier (UID) of the access card. The encrypted operation key may be obtained by encrypting an operation key using a cryptographic key that is also based on the UID of the access card. An access card reader may read the UID from the access card and use it to generate the key used to read the encrypted operation key from the access card. The access card read may also use the UID read from the access card to generate a cryptographic key used to decrypt the encrypted operation key. The access card reader may validate the decrypted operation key and determine whether to grant or deny access, for example, via an access control device.
