The third edition of S60 has greatly improved the security, and has stricter regulations on the third-party software installed and running in the system. Some operations involving mobile phone software and hardware security/personal information security are particularly restricted (for example, automatic startup of mobile phone startup is one of the restricted functions).
In order to realize these "specially restricted" functions, the application must obtain a "signature". In other words, someone should be responsible for the security of this operation, and programs without signatures cannot be installed and run.
Extended data:
There are three kinds of software signatures:
1. Saipan's signature
Which is the official signature of Symbian mobile phone operating system. Only the software that has passed the Symbian security certification can get Symbian's signature. This software has the highest security level.
Can be installed/run normally on the mobile phone/and realize all the functions provided by the software. Obtaining Symbian signature requires the software author to deal directly with Symbian officials. For various reasons, not all software authors have the ability to obtain this certification.
2. Signature of the author.
The author of the software signed his name when he released the software. This kind of software can be installed and run on your mobile phone (you may encounter a security warning and you can skip it). But those "specially restricted" functions cannot be realized. If a software doesn't involve this function at all, it is entirely possible for the software author to sign it himself.
Another possibility is that although some functions of the software are within the scope of "special restrictions", they are not the main functions. The software author may also release an "author's signature version", which can normally use most functions, but will lose some specific functions. For example, there is such a version of the "incoming call" software that almost all functions can be used, but it can't be started automatically.
3. User signature
Strictly speaking, this should belong to the "developer signature". Because Symbian provides a kind of "development certificate" for software developers, the original intention is to let software developers do software testing. This "development certificate" is associated with the IMEI code of the machine used for testing. The software signed with this certificate can only be used on the machine corresponding to the IMEI code, not on other machines.