Keyless encryption of messages using challenge response

• US 6,535,980 B1
• Filed: 06/21/1999
• Issued: 03/18/2003
• Est. Priority Date: 06/21/1999
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Kumar, Suresh, Kumar, Vijay
• Primary Examiner(s): Barron, Gilberto
• Assistant Examiner(s): Gurshman, Grigory
• Application Number:
  US09/337,719
• Time in Patent Office: 1,366 Days
• Field of Search: 380/256, 380/28, 380/278, 713/168, 713/170, 713/171, 713/181, 713/183, 705/75
• US Class Current: 713/168
• CPC Class Codes: H04L 9/3228 One-time or temporary data, i.e. information which is sent for every authentication or authorization, e.g. one-time-password, one-time-token or one-time-key
• CPC Class Codes: H04L 9/3273 for mutual authentication network architectures or network communication protocols for achieving mutual authentication in a packet data network H04L63/0869

Abstract

A method of keyless encryption of messages allows secure transmission of data where data security is not available for some technical or legal reason. The method of data transfer uses a challenge response in which a correct response to a challenge is used to transmit the value “1”, while a deliberately false response is made to transmit the value “0”. Any message can be transmitted as a binary string using successive applications of this method.

Claims

1. A method for sending secret messages comprising a repeated use of an authentication scheme where a successful authentication implies the transmission of a bit of a first value and a deliberate unsuccessful authentication implies the transmission of a bit of a second value, whereby a secret message is transmitted as a binary string each bit of which is determined as either a successful or unsuccessful authentication.

2. The method as in claim 1, where a sender and a receiver agree upon a secret table of challenge response pairs and successful authentication is when the sender sends a correct response to a given challenge, while an unsuccessful authentication is when the sender sends any other response.

3. The method as in claim 2, where the challenge response pairs are automatically generated using a shared secret key and a pair generation algorithm.

4. The method as in claim 3, where a new secret key to generate challenge response pairs is also sent as a secret message when required.

5. The method as in claim 1, where the authentication scheme is a one time password scheme.

6. An apparatus for sending secret messages comprising a sender and a receiver, the sending responding to challenges from the receiver by sending a successful authentication to imply a bit of a first value and a deliberate unsuccessful authentication to imply a bit of a second value, whereby a secret message is transmitted as a binary string each bit of which is determined as either a successful or unsuccessful authentication.

7. The apparatus of claim 6, wherein each of the sender and receiver each include an agreed upon secret table of challenge response pairs and successful authentication is when the sender sends a correct response to a given challenge from the table of challenge response pairs and an unsuccessful authentication is when the sender sends any other response.

8. The apparatus of claim 7, wherein the challenge response pairs of the secret table are automatically generated using a shared secret key and a pair generation algorithm.

9. The apparatus of claim 8, wherein a new secret key to generate challenge response pairs is sent by the sender to the receiver as a secret message.

10. The apparatus of claim 6, wherein the authentication scheme is a one time password scheme.