Self-signing refers to signing with the authorization certificate that comes with the mobile phone, as long as it has not expired or there is no problem! Just download a software installation with a certificate and you will know! If it can be installed, there is no problem with the authorization certificate! Signing means being responsible for the security of mobile phone software. When using mobile phone software, you must have a signature to use some restricted functions! If your mobile phone authorization certificate cannot be used, I suggest you apply for one! Go to the best application of the competition class, where it is easy to use and the cracking authority is higher! And both Dangle and Skynet can apply for a certificate!