SECURITY IN COMMUNICATIONS NETWORKS

摘要

The invention provides a method of providing secure data communication between a client device and a network device, wherein the method comprises arranging a periodically varying broadcast code (N) to be transmitted such that the network and client devices have knowledge of the broadcast code (N), providing the network and client devices each with the same secret key code (K) and encryption/decryption algorithm, wherein the algorithm is arranged to encrypt and decipher a encrypted transmission data code used for network authentic data transmissions between the client and network devices, and wherein the encrypted data code is generated from a combination of the data and a secret key (X) which is itself derived from a combination of the secret key code (K) and broadcast code (N). One embodiment provides that the broadcast code (N) is transmitted on request by a network/client device. Another embodiment provides that the ACK frame of a data transmission between client/network devices is used to send notifications of the fact that the broadcast code (N) has changed.