The security protection method and system described in this invention pre-save a serial number of identification in the mobile terminals. The network equipment checks the serial number of identification. If the identification is not passed, the mobile terminals are defined as illegal users, to prohibit the use of network through the mobile phones or lock them by the service provider's network when they are lost of stolen. The serial number of identification (such as 128bit summary information) is stored in the flash memory with a OTP function of one-time programming through the MD5 encryption on IMEI, which can only be written one time and has finished when the mobile phone leaves the factory. The content read out from the second time of writing is not the same one of the writing. |