The invention related to method for providing connection security for the transmission between communicating parties in a telecommunication network, the method comprising the steps of: exchanging security parameters between communicating parties, providing connection security for messages based on these security parameters, and transmitting said messages between communicating parties. It is characteristic for the method according to the invention that it further comprises the steps of: reaching agreement between communicating parties on an interval for recalculation of the security parameters, monitoring of the interval for recalculation by the communicating parties, recalculating the security parameters at the agreed interval, and providing connection security for messages based on the latest recalculated security parameters.