Method and system for securely exchanging encryption key determination information

• US 7,085,376 B2
• Filed: 02/14/2001
• Issued: 08/01/2006
• Est. Priority Date: 02/14/2001
• Status: Expired due to Fees

• Current Assignee: Anixa Biosciences, Inc. (f/k/a ITUS Corporation)
• Original Assignee: Anixa Biosciences, Inc. (f/k/a ITUS Corporation)
• Inventors: DiSanto, Frank J., Krusos, Denis A.
• Primary Examiner(s): Revak, Christopher
• Assistant Examiner(s): Chai, Longbit
• Application Number:
  US09/782,825
• Publication Number:
  US 20020150237A1
• Time in Patent Office: 1,994 Days
• Field of Search: 713/169, 713/176, 380/277, 380/304, 380/28, 380283-285, 380 44- 45, 726 5- 6
• US Class Current: 380/28
• CPC Class Codes: H04L 9/0891 Revocation or update of secret information, e.g. encryption key update or rekeying
• CPC Class Codes: H04L 9/12 Transmitting and receiving encryption devices synchronised or initially set up in a particular manner
• CPC Class Codes: H04L 9/16 the keys or algorithms being changed during operation

Abstract

A system and method for securely exchanging plurality of information items used to generate a plurality of encryption keys used in a public key-and-private key system. In accordance with the principles of the invention, elements of exchanged information items, such as public key and synchronizing indictors are encrypted before the exchange. The information item element is encrypted using an encryption key determined from information items that were previously exchanged. The encryption of information items used to determine subsequent encryption keys provides additional security to the encryption key used in the transmission of informational data as the encrypted elements of the information item must be decrypted before the data message encryption key can be decrypted. The process of exchanging encrypted information items can be repeated until an agreed upon number of encrypting keys is determined.

Claims

1. A computer implemented method for facilitating secure electronic communications among at least two parties over a communication network, comprising:

retaining a first private key and transmitting a corresponding first initial public key and synchronizing indicator;

using a received second public key and second synchronizing indicator in combination with said retained first private key to determine, and retain, a first encryption key;

determining a second private key, a third public key and a third synchronizing indicator, wherein said second private key is retained with said first retained private key;

encrypting at least said third synchronizing indicator using said first encryption key;

transmitting said third public key and encrypted third synchronizing indicator;

decrypting a received fourth synchronizing indicator using said first encryption key; and

determining a second encryption key from retained said second private key, a received fourth public key and decrypted said received fourth synchronizing indicator;

wherein said second encryption key is retained with said first encryption key, and

said first and second encryption keys are dependent upon said second and fourth synchronizing indicators, respectively, such that if said first and second encryption keys are determined using different synchronizing indicators, data encrypted using said first and second encryption keys provides different encrypted data, respectively, and wherein said synchronizing indicators are used to alter the starting position of the encrypting sequence with the corresponding public keys.

2. The method as recited in claim 1 wherein said determining a next private key and a next information item set, encrypting at least one element of said next information item set, transmitting said encrypted next information element, decrypting said received encrypted information item element;

and, determining a next encryption key from said next private key and said decrypted information item are repeated until a known number of encryption keys are determined.

3. The method as recited in claim 1 wherein the step of encrypting further comprises:

selecting at least one of said retained encryption keys alternatively.

4. The method as recited in claim 3 wherein said encryption keys are selected in a known sequence.

5. The method as recited in claim 4 wherein said known sequence corresponds to an order of retention of said encryption keys.

6. The method as recited in claim 4 wherein said known sequence corresponds to an order pre-selected by said parties.

7. The method as recited in claim 1, wherein the step of encrypting further comprises:

selecting a known encryption key.

8. The method as recited in claim 7 wherein said known encryption key is such that an output value is the same as an input value.

9. The method of claim 1, wherein said synchronizing indicators correspond to select bit positions.