Payment cipher device for telephone bank

The utility model relates to a payment cipher device for telephone bank which is composed of a single-chip microcomputer (1), a keyboard matrix circuit (2), a parameter memory (3), a dual tone frequency modulation and amplifying circuit (4), a liquid crystal display module (5), the switching circuits (6), (7) and a mini horn (8). The program memory of the single chip computer is enciphered and solidified with a set of cipher algorithm. When the needed bank account information is inputted by the keyboard, the dual tone frequency signal which stands for the 'digital signature ' or 'account ciphertext ' is generated, corresponding to each service. The dual tone frequency modulation signal is sent out from the mini horn (8) by amplified. The user using the device can transact various bank services by the public telephone network and the electronic computer system of the bank with the dialog form. The card with award sales-promoting function is secret and fast.