Patent ID: 8908863

Claim:
A method for negotiating encryption algorithms in a communication system, wherein the communication system comprises a core network element, an access network element and a mobile station (MS), and wherein an A5/4 encryption algorithm is not supported by a plug-in card of the MS, the method comprising: obtaining, by the core network element, an authentication vector of the MS; determining, by the core network element, an encryption algorithm list excluding the A5/4 encryption algorithm according to that a key part of the authentication vector of the MS includes a 64-bit encryption key; and sending, by the core network element, the encryption algorithm list to the access network element, to ensure that an encryption algorithm excluding the A5/4 encryption algorithm is selected by the access network element for data encryption, even if an encryption algorithm list including the A5/4 encryption algorithm is sent by the MS to the access network element wherein the encryption algorithm list-excluding the A5/4 encryption algorithm is used for the access network element to select an encryption algorithm supported by the core network element and the MS both.