A bankcard password protection method for a point-of-sale, POS, device comprising an application processor and a security processor, comprising the steps: randomly generating a public and private key pair, by the security processor; sending the public key to the application processor, by the security processor; acquiring a numerical bankcard password as a personal identification number, PIN, encrypting the bankcard password by means of the public key and transmitting the encrypted bankcard password to the security processor, by the application processor; and decrypting the bankcard password by means of the private key, by the security processor, further comprising the steps: displaying a random disorganized numeric keypad, used for bankcard password input for acquiring the bankcard password from a customer, on a touch screen of the application processor, wherein every time the numeric keypad is displayed on the touch screen, a drive or service related to bankcard password input of the touch screen will display the numeric keypad according to a set of random numbers; and configuring a system setting to a special mode for entering the bank card password when the bankcard password is input to the touch screen of the application processor, wherein in the special mode a special touch screen password drive will intercept password input events on the hardware level to make sure that all password input events are only available to the special touch screen password drive to be processed and will not be reported to common application programs. randomly generating a public and private key pair, by the security processor; sending the public key to the application processor, by the security processor; acquiring a numerical bankcard password as a personal identification number, PIN, encrypting the bankcard password by means of the public key and transmitting the encrypted bankcard password to the security processor, by the application processor; and decrypting the bankcard password by means of the private key, by the security processor, further comprising the steps: displaying a random disorganized numeric keypad, used for bankcard password input for acquiring the bankcard password from a customer, on a touch screen of the application processor, wherein every time the numeric keypad is displayed on the touch screen, a drive or service related to bankcard password input of the touch screen will display the numeric keypad according to a set of random numbers; and configuring a system setting to a special mode for entering the bank card password when the bankcard password is input to the touch screen of the application processor, wherein in the special mode a special touch screen password drive will intercept password input events on the hardware level to make sure that all password input events are only available to the special touch screen password drive to be processed and will not be reported to common application programs. displaying a random disorganized numeric keypad, used for bankcard password input for acquiring the bankcard password from a customer, on a touch screen of the application processor, wherein every time the numeric keypad is displayed on the touch screen, a drive or service related to bankcard password input of the touch screen will display the numeric keypad according to a set of random numbers; and configuring a system setting to a special mode for entering the bank card password when the bankcard password is input to the touch screen of the application processor, wherein in the special mode a special touch screen password drive will intercept password input events on the hardware level to make sure that all password input events are only available to the special touch screen password drive to be processed and will not be reported to common application programs.