Data on the smart card is said to be relatively secure because it is difficult to extract encrypted data from the outside and difficult to alter it. It can also store other confidential information such as credit card numbers and personal identification details. When mobile phones are equipped with a device to protect personal information, the security level of an entire service, including the network, improves considerably. In order to strengthen an entire system you have to make one part that cannot be analyzed. When the mobile phone is equipped with a smart card, it can show a terminal certificate verifying that it is an authorized terminal.
Various means exist to verify identity, including fingerprints, iris and voice patterns.
A number of manufacturers are already developing biometric technologies capable of verifying user identity, and some have already entered into practical use in PCs and similar applications. It remains unclear when they will be available for use in mobile phones, since problems with size and cost remain to be resolved. Just the development of a method for implementing terminal certificates via a network alone would represent a major step forward from what is now possible. The constituent technologies of PKI are an electronic certificate issued by a special certifying party and the encryption technology based on public and private keys. The basic concept here is to swap electronic certificates through a network to mutually verify terminal identities and encrypt swapped data to prevent eavesdropping or tampering.