What's the difference between Nokia SIS and SIXX?

Organic friends often have questions when installing software. Why are there sisx suffixes and sisx suffixes? What is the difference between the two softwares? Let's start with the priority of sis: in the early days, there was no third edition software installer on Nokia smartphones, and only a small part of it could run on the third edition, which is why many downloaded sis could not be used on our third edition phones. With the popularity of SIXX, sis will gradually disappear from the third edition of mobile phones. The browser of the third edition mobile phone is not allowed to download sis, but OP can, so we often hear "Please download with OP". Sisx: a program specially developed for the third edition, which can't run on the mobile phone without the third edition system. Symbian 9.0 and later introduced a new system security model. As more and more personal information (such as phone books and business secret documents) will be stored in smart phones, it is necessary to prevent malicious software or viruses from stealing this information or consuming users' communication expenses. Users will notice that all files of the software installed in the previous system will be stored in the \system\apps\xxx directory. In Symbian 9.0 and later systems, different files in the software will be stored in different directories. Executable files (. It used to be exe. App) are placed under \sys\bin, resource files are placed under \resource, and all private data of each software are placed under \ private \; Directory, other directories are shared by all software. Users \sys\bin and \resource cannot be changed, and executable files can only be copied by the installer. \ Private \< Software Security Number; Can only be accessed by the software corresponding to the software security number. The executable file introduces the competency model. In order to obtain some functions, such as accessing the user's phone book, sending short messages and modifying mobile phone settings, it is necessary to obtain the digital signature of the executable file from Saipan or Nokia. The system also has the function of preventing executable files from being edited. Using the card reader to install the modified software package or modify the \sys\bin directory of the memory card will be discovered by Symbian system. By introducing these features, the security of the system is greatly improved, and all kinds of private data can be safely stored in the mobile phone. However, the introduction of system security model is another important reason for system compatibility problems. The installation file formats of the first two platforms are s is format, which is easy to modify, and the system has almost no preventive ability. In other words, the system will still execute destructive execution code, but on S60 v3, sis is just an unsigned file, so it cannot be installed directly with sis. From the user's point of view, sis needs to be certified as SIN 1 (remember, this does not mean that the installation file of S60 platform can run on the 3rd edition with a simple certificate SIN, because the essence in sis is completely different and the architecture is not universal). There are two kinds of certificates here, one is a free certificate, which has low authority but is very extensive. Now it is repackaged. (cncn6.com released by Saipan Smartphone Studio) Simply put, sis can run in the third edition, but it is not right. SIXX is currently dedicated to the third edition, but it cannot run in other second editions.