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 kind 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.

To obtain Symbian signature, the software author needs 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 software author signed the software when he released it. This kind of software can be installed and run on the mobile phone (you may encounter a security warning and can skip it). But those functions that are "specially restricted" cannot be realized. If a software doesn't involve this kind of function at all, then it is entirely possible for the software author to sign it himself. Another possibility is that although some functions of the software belong to the "specially restricted" scope, they are not the main functions. The software author may also publish 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 telegram" software, and almost all functions can be used, but it can't be started automatically.

3. User signature.

strictly speaking, this should belong to the "developer's 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 linked to 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, and cannot be used on other machines.

our so-called "self-signature" actually uses this method. To put it bluntly, you say that you are developing software, you provide the IMEI code of your test machine, and Symbian issues you a "development certificate", with which you sign your "test software". You are 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 to the use time of the signed program within the validity period of the certificate.

A few more words, the formal steps to apply for the "development certificate" are as follows: (Please refer to the relevant tutorials for specific operations. Here are only the general steps)

1. Register a user on Symbian's official website

2. Download an authentication request tool: DevCertRequest

3. Install and run the DevCertRequest tool on your PC, fill in your machine's IMEI code, and generate a. csr file, which is actually an identification file formed by your IMEI code through a specific algorithm.

4. Log in to Symbian official website again and submit (upload). csr file, and Symbian will generate a development certificate according to the identification file.

5. Download the development certificate and use the signing tool to write the development signature into the application.

Someone asked Symbian official website why he didn't let users directly enter your IMEI code on the website and then download the development certificate directly. It's so troublesome to download a tool to form an identification file locally and upload it. What is the reason? 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 belongs to the scope of privacy. Symbian does not directly input this information on the website to protect the privacy of users.

the. csr file formed by DevCertRequest is encrypted by IMEI information, but the user's IMEI code cannot be calculated by any means.

It is beyond the scope of this post to discuss whether it is appropriate to publish the IMEI code on the forum at will and what the consequences will be if the IMEI is leaked. However, users should be reminded that they should have a little privacy awareness. They often see posts asking how to turn off the shutter sound of N73 camera and how to turn off the flash. In fact, to put it bluntly, it is to prevent candid shots.