A mobile phone certificate is similar to a person's ID card. You need to handle some business or something, you need an ID card, and you need a pass to load non-Nokia programs on your mobile phone. This is the so-called certificate. It is not enough to have a certificate. You need to download a signed program online, that is, add a certificate to the program, so that you can install the program smoothly, which means that the mobile phone recognizes the legitimacy of the program you installed. That is, signature. Cracking is to change some settings and programs according to system vulnerabilities, so that your mobile phone no longer receives the restrictions of certificates, or there are few restrictions, and basically commonly used software programs can be installed directly. I hope I can help you add points! ~