A method of updating/recovering a configuration parameter of a mobile terminal having stored thereon a public key of a public-key cryptosystem and a current terminal identifier, the method comprising determining an updated configuration parameter by an update/recovery server in response to a received current terminal identifier from the mobile terminal; generating an update/recovery data package by a central signing server, the update/recovery data package including the current terminal identifier, the updated configuration parameter, and a digital signature based on a private key, where the digital signature is verifiable by said public key; storing the current terminal identifier and the updated configuration parameter by the central signing server; sending the update/recovery data package by the update/recovery server to the mobile terminal causing the mobile terminal to verify the received update/recovery data package and to store the! updated configuration parameter of the verified update/recovery data package in the mobile terminal.