● Lock if SIM card changed — You can set thedevice to ask for the lock code when an unknownSIM card is inserted into your device. The devicemaintains a list of SIM cards that are recognisedas the owner’s cards.● Closed user group — You can specify a group ofpeople to whom you can call and who can callyou (network service).● Confirm SIM services — You can set the deviceto display confirmation messages when you areusing a SIM card service (network service).Certificate managementPress , and select Tools > Settings >General > Security > Certificate management.Digital certificates do not guarantee safety; they areused to verify the origin of software.In the certificate management main view, you cansee a list of authority certificates that are stored inyour device. Scroll right to see a list of personalcertificates, if available.Digital certificates should be used if you want toconnect to an online bank or another site or remoteserver for actions that involve transferringconfidential information. They should also be usedif you want to reduce the risk of viruses or othermalicious software and be sure of the authenticityof software when downloading and installingsoftware.Important: Even if the use of certificatesmakes the risks involved in remote connections andsoftware installation considerably smaller, theymust be used correctly in order to benefit fromincreased security. The existence of a certificatedoes not offer any protection by itself; thecertificate manager must contain correct,authentic, or trusted certificates for increasedsecurity to be available. Certificates have arestricted lifetime. If "Expired certificate" or"Certificate not valid yet" is shown even if thecertificate should be valid, check that the currentdate and time in your device are correct.Before changing any certificate settings, you mustmake sure that you really trust the owner of thecertificate and that the certificate really belongs tothe listed owner.View certificate details—check authenticityYou can only be sure of the correct identity of aserver when the signature and the period of validityof a server certificate have been checked.You are notified if the identity of the server is notauthentic or if you do not have the correct securitycertificate in your device.To check certificate details, scroll to a certificate,and select Options > Certificate details. Whenyou open certificate details, the validity of the144 Settings
