Verbally speaking, the mobile phone of S60V3 system has 20 levels of authority, and some software needs to use some functions of the mobile phone when installing or using it. The network (including incidental expenses) is either written into some files of the system or automatically started when it is turned on, which requires different levels of authority. In addition, it is also anti-virus, because every software developed must be submitted to the official organization Saipan for review, and then signed in with different levels of certificates before it can be released to the software side. Software signed with public certificate (i.e. unsigned version) can be installed within the validity period, while unsigned version (i.e. self-signed version) (generally requiring higher authority) can be successfully installed or started randomly within the validity period after being signed with signed software and personal certificate (related to the serial number of mobile phone).

Hehe, not very comprehensive.