Puheen ja ohjaussanomien salakirjoittaminen solukkojärjestelmässä

摘要

A protocol for authenticating a mobile customer unit to a service provider where signaling messages are encrypted and where voice communications can be encrypted. A service provider assigns to each mobile customer unit a unique "secret", along with other information such as a telephone number. At the pleasure of the service provider, a directive is sent to the mobile customer unit to create a shared secret datum based on the secret. The shared secret datum is created with the aid of a bit string that is sent for that purpose by the provider. A portion of the created shared secret datum is used for encrypting speech and the same or other portion of the created shared secret datum is used as an input to a process for creating a second encryption key. That key is employed in the mobile customer unit to encode those of the control signals generated by the mobile customer unit that affect the nature of the call in progress.