1. Symbian signature.
That is the official signature of Symbian mobile operating system. Only software that has passed Symbian security certification will obtain Symbian's
signature. This type of software has the highest security level. It can be installed/run normally on the mobile phone and can realize all the functions provided by the software.
Obtaining a Symbian signature requires the software author to deal directly with Symbian officials. Due to various reasons,
Not all software authors have the ability to obtain this certification.
2. Author’s signature.
Software authors sign the software when they release it. This type of software can be installed and run on mobile phones (you may encounter security warnings, which can be skipped). However, those "specially restricted" functions cannot be implemented. If a piece of software does not involve such functions at all, then the software author may just sign it himself. Another possibility is that although some functions of the software fall into the "specially restricted" range, they are not the main functions. The software author may also release an "author-signed version", which can use most functions normally, but will lose some specific functions. For example, the "Laitengtong" software has such a version, almost all functions can be used, but it cannot start automatically when the computer is turned on.
3. User signature.
Strictly speaking, this should be a "developer signature". Because Symbian provides a "development certificate" for software developers, the original intention was to allow software developers to conduct software testing. This "development certificate" is linked to the IMEI code of the machine used for testing. Software signed with this certificate can only be used on the machine corresponding to the IMEI code and cannot be used on other machines.
What we call "self-signing" actually uses this method. To put it bluntly, you say you are developing software, you provide the IMEI code of your test machine, and Symbian issues you a "development certificate" , you use this certificate to sign your "test software". You are solely responsible for your own "development behavior"! That's all. In addition, the development certificate is valid for half a year from the date of issuance. However, there is no limit on the use time of the program signed within the validity period of the certificate.
A few more words, a formal application for a "development certificate" The steps are as follows: (Please refer to the relevant tutorials for specific operations, here I will only outline the steps)
1. Register a user on the official Symbian website
2. Download a certification request Tool: DevCertRequest
3. Install and run the DevCertRequest tool on your PC, fill in the IMEI code of your machine, and generate a .csr file, which is actually yours
The IMEI code is an identification file formed by a specific algorithm.
4. Log in to the Symbian official website again, submit (upload) the .csr file, and Symbian will generate a development certificate based on the identification file.
5. Download the development certificate and use the signing tool to write the development signature into the application.
Someone asked the Symbian official website why it does not allow users to enter your IMEI code directly on the website and then Just download the development certificate directly. It is so troublesome to use a tool locally to form an identification file and then upload it. What's the reason? It is to protect user privacy.
IMEI=International Mobile Equipment Identity=International Mobile Equipment Identity Card. This is similar to your "resident ID card". This thing falls within the scope of privacy. Symbian does not enter this information directly on the website out of consideration for protecting user privacy.
The .csr file formed by DevCertRequest is encrypted by IMEI information, but the user's IMEI code cannot be calculated back by any means.
Whether it is appropriate to publish IMEI numbers randomly on forums and what the consequences of leaking IMEI numbers are beyond the scope of this post. However, I still remind users to be a little privacy conscious. I often see posts asking how to turn off the shutter sound of the N73 camera, how to turn off the flash, etc. In fact, to put it bluntly, it is to prevent secret photography.