Patent ID: 8028161
Filing Date: 2011-09-27
Classification: H04L

Abstract:
1. A method for computer-aided negotiation of a security association on an application layer between a first computer and a second computer, the first computer and the second computer being coupled to one another via a telecommunication network, comprising: transmitting in a first SIP-compatible message along with a random number and authentication data, a list of more than one possible security association between the first computer and the second computer from the first computer to the second computer according to SIP protocol of the application layer, an integrity algorithm, a validity time period, and a security parameter index being included for and assigned to each security association in the list, each security parameter index identifying a corresponding security association in the list, said security associations including a maximum life of the security associations; respectively determining cryptographic parameters for a cryptographically protected communication link in a network layer to be set up using the security association, selecting a security association by the second computer from among the list of more than one possible security association received using said first SIP-compatible message, and transmitting to the first computer in a second SIP-compatible message at least one of the security association selected by the second computer and an indication of the security association selected by the second computer to be used by the first and second computer without reselecting a new security association for the validity time period, wherein the first computer is a mobile communication terminal and the second computer is a mobile radio network computer and a communication link is set up using the security association selected.