GB1404366A - Personal authority vertification system - Google Patents

Abstract

1404366 Selective signalling CENTURY INTERNATIONAL CO Ltd 24 July 1972 34548/72 Heading G4H Documents such as cheques, credit cards bear enciphered information to make unauthorized use and counterfeiting more difficult. In one embodiment, a cheque stub 1, Fig. 1, is printed with a randomly generated alphabet display in which each letter is associated with a mark 11 or a space. The 26-bit random-word corresponding to the alphabet display is enciphered with the binary coded cheque number using transformation matrices and a feedback shift register, Fig. 2 (not shown), and the resulting enciphered infromation is printed on portion 3 of the cheque. Each account is assigned a unique code name known to the holder of the account, and when filling in a cheque, the account holder records a code signature 5 comprising marks and spaces appropriate to the letters of the code name according to the alphabet display 1 which is different for each cheque. Fig. 3 shows apparatus for checking the authenticity of a cheque and the authority of the user. The account number 9 is sensed and used at 74 to retrieve the corresponding code name which is entered in a register 64. The binary coded cheque number 7 is sensed and compared at 76 with the numbers of cheques previously drawn on the account and held in a store 72 to provide one input to a gate 78 if a cheque with that number has not been used previously. The enciphered information 3 is sensed and deciphered using the reverse process to the enciphering operation. The information is fed to a transformation matrix 44 the outputs of which are selectively supplied to a shift register 46 and a counter 54. Register 46 is shifted backwards a number of times equal to the number set in counter 54, at the end of which operation matrix 50 supplies the deciphered random alphabet display word to register 60 and the cheque number to register 68. The recovered cheque number is compared at 70 with the sensed cheque number 7 to provide a second input to gate 78 on equality. The contents of registers 60, 64 and 66 are gated together at 62 to provide the final enabling input to gate 78 if the sensed code signature corresponds to the retrieved code name as encoded by the deciphered alphabet display word. In a further embodiment, a credit card is provided with a binary coded account number and an encipherment of the account number with a code name for that account. When the card is used, the holder fills in a charge slip with a code signature as above, the alphabet display being provided on the charge slip instead of on the card. The card is then sensed and deciphered to check the account number, and the charge slip is also sensed to check the code signature, both checks being performed in a manner similar to that described above, Fig. 7 (not shown).