Digital signature verification technology for smart credit card and internet applications

• US 5,613,001 A
• Filed: 01/16/1996
• Issued: 03/18/1997
• Est. Priority Date: 01/16/1996
• Status: Expired due to Fees

• Current Assignee: Ezzat G. Bakhoum
• Original Assignee: Ezzat G. Bakhoum
• Inventors: Bakhoum, Ezzat G.
• Primary Examiner(s): Buczinski, Stephen C.
• Application Number:
  US08/587,026
• Time in Patent Office: 427 Days
• Field of Search: 380/3, 380/4, 380/23, 380/25, 380/48
• US Class Current: 380/254
• CPC Class Codes: G06Q 20/341 Active cards, i.e. cards including their own processing means, e.g. including an IC or chip
• CPC Class Codes: G06Q 20/367 involving electronic purses or money safes
• CPC Class Codes: G06Q 20/4097 using mutual authentication between devices and transaction partners
• CPC Class Codes: G07F 7/1008 Active credit-cards provided with means to personalise their use, e.g. with PIN-introduction/comparison system
• CPC Class Codes: H04L 2209/04 Masking or blinding
• CPC Class Codes: H04L 2209/12 Details relating to cryptographic hardware or logic circuitry
• CPC Class Codes: H04L 2209/56 Financial cryptography, e.g. electronic payment or e-cash
• CPC Class Codes: H04L 9/3234 involving additional secure or trusted devices, e.g. TPM, smartcard, USB or software token network architectures or network communication protocols for supporting authentication of entities using an additional device in a packet data network H04L63/0853
• CPC Class Codes: H04L 9/3247 involving digital signatures
• CPC Class Codes: H04L 9/3271 using challenge-response

Abstract

The presently used Asymmetric Digital Signature verification technologies, such as the system of RSA Data Security Corp., require complex mathematical operations for encryption and decryption. As a result, today'"'"'s smart credit cards have built-in microprocessors, sophisticated arithmetic/logic units, and large amounts of RAM and ROM. For smart card applications, both the cost and the complexity of such systems is prohibitive. The present invention introduces a smart card technology that uses fairly simple logic circuitry, together with a novel handshaking technique, to achieve an outstanding level of security while maintaining simplicity and low cost.

Claims

1. A handshaking method between a computer and a smart digital system, consisting of:

a test signal, issued by the computer system;

a confirmation signal, issued by the smart digital system;

wherein the confirmation signal comprises a masked form of the test signal, mixed with other irrelevant data, such that the locations of the masked signal within said irrelevant data are known to the computer system.

2. A method according to claim 1, wherein the smart digital system is a computer.

3. A method according to claim 1, wherein the smart digital system is a hardware device attached to a plastic card.

4. A method according to claim 1, wherein the smart digital system generates irrelevant data by means of a pseudo-random bit generator.

5. A method according to claim 4, wherein the pseudo-random bit generator is driven by the masked test signal.

6. A method according to claim 1, wherein the smart digital system comprises cyclic shift registers and control circuitry for allocation of the masked test signal.

7. A method according to claim 1, wherein the masked signal is a digital signature.

8. A method according to claim 1, wherein the masked signal is a secret message.

9. A method according to claim 1, arranged for securing financial transactions.

10. A method according to claim 1, arranged for securing Internet communications.