A method for creating a key pair in a telecommunications system comprises a user terminal and at least one network node serving the user terminal. In the method, upon a successful user authentication, a first seed value is composed in the user terminal and a second seed value is composed in the network node, such that the seed values are identical. Based on the seed values, respective public/private key pairs are generated, such that the generated public/private key pair in the user terminal and the generated public/private key pair in the network node are identical.