Patent ID: 6654883
Filing Date: 2003-11-25
Classification: G06Q,G07B,H04L

Abstract:
A device authentication and encrypted communication system comprising a plurality of user devices, a system device, and a control device, where device authentication and encrypted communication are performed between the plurality of user devices and the system device, according to a symmetric secret key encryption algorithm,wherein, each of the plurality of user devices stores a piece of secret information that is unique to the user device, and the control device: (a) produces pieces of key capsule data by performing a specified conversion on pieces of unique secret information in each of the plurality of user devices, the unique secret information in each user device comprising a secret key for use in encrypted communication with that user device using a symmetric encryption algorithm; (b) provides each user device with a piece of key capsule data that has been produced from the piece of secret information stored in the user device; and (c) provides the system device with a specified key that enables the system device to obtain pieces of secret information of user devices from pieces of key capsule data provided by the user devices, the user device transmits the piece of key capsule data received from the control device to the system device, the system device recovers the piece of secret information stored in the user device from the piece of key capsule data received from the user device using the specified key, and during device authentication and encrypted communication between one of the user devices and the system device, the user device and the system device perform one of encryption and decryption according to a symmetric secret key encryption algorithm, using the piece of secret information that is unique to the user device as a symmetric secret key.