Method and apparatus for encrypting data in a wireless communication system

• US 7,995,751 B2
• Filed: 03/30/2004
• Issued: 08/09/2011
• Est. Priority Date: 03/11/1997
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Rose, Gregory G.
• Primary Examiner(s): Moise; Emmanuel L
• Assistant Examiner(s): CALLAHAN, PAUL E
• Application Number:
  US10/814,065
• Publication Number:
  US 20040190712A1
• Time in Patent Office: 2,688 Days
• Field of Search: 380/30, 380/201, 380/251, 380/262, 380/28, 380/29, 380/42, 380/44, 713/181, 713/152, 713/188, 713/153, 713/160, 705/67, 705/57, 455/410, 455/411
• US Class Current: 380/44
• CPC Class Codes: H04L 9/06 the encryption apparatus using shift registers or memories for block-wise or stream coding, e.g. DES systems or RC4; Hash functions; Pseudorandom sequence generators
• CPC Class Codes: H04L 9/0618 Block ciphers, i.e. encrypting groups of characters of a plain text message using fixed encryption transformation

Abstract

In a communications system, a method of transforming a set of message signals representing a message comprising the steps of first encoding one of the set of message signals in accordance with a first keyed transformation, a second encoding of the one of the set of message signals in accordance with at least one additional keyed transformation, a third encoding of the one of the set of message signals in accordance with a self inverting transformation in which at least one of the set of message signals is altered, a fourth encoding of the one of the set of message signals in accordance with at least one additional inverse keyed transformation wherein each of the at least one additional inverse keyed transformation is a corresponding inverse of at least one additional keyed transformation, and fifth encoding the one of the set of message signals in accordance with first inverse keyed transformation wherein the first inverse keyed transformation is the inverse of the first keyed transformation.

Claims

1. In a communications system, a method of transforming a set of message signals representing a message comprising:

first encoding one of said set of message signals in accordance with a first keyed transformation by a hardware processor;

second encoding said one of said set of message signals in accordance with at least one additional keyed transformation by the hardware processor;

third encoding said one of said set of message signals in accordance with a self inverting transformation in which at least one of said set of message signals is altered by the hardware processor;

fourth encoding said one of said set of message signals in accordance with at least one additional inverse keyed transformation wherein each of said at least one additional inverse keyed transformation is a corresponding inverse of said at least one additional keyed transformation by the hardware processor; and

fifth encoding said one of said set of message signals in accordance with first inverse keyed transformation by the hardware processor wherein said first inverse keyed transformation is the inverse of said first keyed transformation;

wherein said step of first encoding is performed in accordance with a first table and in a first direction, and wherein said step of second encoding is performed in accordance with said first table.

2. The method of claim 1, wherein said step of second encoding is performed in accordance with said first table in said first direction.

3. The method of claim 1, wherein said step of fourth encoding is performed in accordance with at least one additional direction.

4. The method of claim 1, wherein said step of fifth encoding is performed in accordance at least one additional direction.

5. The method of claim 1, wherein said first table is a permutation.

6. The method of claim 1, wherein said step of third encoding is performed in accordance with a keyed transformation.

7. The method of claim 1, wherein said step of third encoding is performed in accordance with an unkeyed transformation.

8. The method of claim 1, wherein said first keyed transformation comprises the steps of:

receiving an index value;

receiving a table; and

performing a table lookup in accordance with said index value and said table.

9. The method of claim 8, further comprising processing said index value and

wherein said step of performing a table lookup is performed in accordance with the result of said processing of said index value.

10. The method of claim 9, further comprising additional processing on the result of said table lookup.

11. The method of claim 10, wherein said additional processing on the result of said table lookup comprises performing additional table lookups in accordance with said result.

12. The method of claim 10, wherein said additional processing on the result of said table lookup comprises performing Boolean operations on said result.

13. A method of transforming a set of message signals in a communication system, the method comprising:

generating a table by strict permutations by a hardware processor;

first encoding one of said set of message signals in accordance with a first keyed transformation by the hardware processor;

second encoding one of said set of message signals in accordance with a self inverting transformation in which at least one of said set of message signals is altered by the hardware processor; and

third encoding one of said set of message signals in accordance with a second keyed transformation by the hardware processor, wherein said second keyed transformation is the inverse of said first keyed transformation;

wherein the first and third encoding is performed in accordance with said table, and wherein the first and third encoding are performed in alternating directions.