Method and apparatus for encrypting data

• US 20030068038A1
• Filed: 09/28/2001
• Published: 04/10/2003
• Est. Priority Date: 09/28/2001
• Status: Abandoned Application

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Hanounik, Bedros
• Application Number:
  US09/968,262
• Publication Number:
  US 20030068038A1
• Time in Patent Office: Days
• US Class Current: 380/37
• CPC Class Codes: H04L 2209/12 Details relating to cryptographic hardware or logic circuitry
• CPC Class Codes: H04L 9/0625 with splitting of the data block into left and right halves, e.g. Feistel based algorithms, DES, FEAL, IDEA or KASUMI

Abstract

To improve data encryption and/or decryption, look-up tables in the field programmable gate array are used to store preselected values for the substitution box used in many encryption/decryption schemes. Utilizing look-up tables in such a manner reduces the overall gate count in the FPGA device resulting in quicker speeds, lower power consumption, and the ability to reconfigure the device for different encryption/decryption implementations.

Claims

1. A circuit to perform at least one of data encryption and data decryption, comprising:

a programmable gate array including at least one substitution box, said substitution box including at least one look-up table;

wherein said at least one look-up table is to receive m input bits and to generate an n-bit output signal where the n-bit output value is selected from a number of preselected values.

2. The circuit of claim 1 wherein m is 6 and n is 4

3. The circuit of claim 2 wherein said at least one look-up table is to store 16 preselected values.

4. The circuit of claim 1 wherein said substitution box includes first, second, third, and fourth look-up tables.

5. The circuit of claim 4 wherein m is 6 and n is 4.

6. The circuit of claim 5 wherein each of said look-up tables is to store 16 preselected values and said m inputs are to be used to select one preselected value from said look-up tables.

7. The circuit of claim 4 wherein a subset of said m input bits are used to select one preselected value from each of said first, second, third, and fourth look-up tables.

8. The circuit of claim 7 further comprising:

a first multiplexer coupled to outputs of said first and second look-up tables;

a second multiplexer coupled to outputs of said third and fourth look-up tables; and

a third multiplexer coupled to outputs of said first and second multiplexers, wherein one of said m input bits is to control said first and second multiplexers and a second of said m input bits is to control said third multiplexer.

9. A circuit to perform at least one of data encryption and data decryption, comprising:

a programmable gate array including at least first, second, third, and fourth substitution boxes, each of said substitution boxes including first, second, third, and fourth look-up tables;

wherein said look-up tables are to generate an n-bit output signal where the n-bit output value is selected from a number of preselected values.

10. The circuit of claim 9 wherein each look-up table is to store 16 preselected values.

11. The circuit of claim 10 wherein m input bits are to be supplied to said substitution boxes to select said n-bit output value.

12. The circuit of claim 11 wherein m is 6 and n is 4.

13. The circuit of claim 12 wherein a subset of said m input bits are used to select one preselected value from each of said first, second, third, and fourth look-up tables in each of said substitution boxes.

14. The circuit of claim 13 wherein each of said substitution boxes includes

a first multiplexer coupled to outputs of said first and second look-up tables;

a second multiplexer coupled to outputs of said third and fourth look-up tables; and

a third multiplexer coupled to outputs of said first and second multiplexers, wherein one of said m input bits is to control said first and second multiplexers and a second of said m input bits is to control said third multiplexer.

15. A method of performing at least one of data encryption and data decryption, comprising:

supplying m input bits to a substitution box in a programmable gate array, said substitution box including at least one look-up table;

generating an n-bit output signal from said at least one look-up table where the n-bit output value is selected from a number of preselected values.

16. The method of claim 15 wherein m is 6 and n is 4

17. The method of claim 16 wherein said at least one look-up table is to store 16 preselected values.

18. The method of claim 17 wherein said substitution box includes first, second, third, and fourth look-up tables.

19. The method of claim 18 further comprising:

selecting with a subset of said m input bits one preselected value from each of said first, second, third, and fourth look-up tables.

20. The method of claim 19 wherein said substitution box includes a first multiplexer coupled to outputs of said first and second look-up tables, a second multiplexer coupled to outputs of said third and fourth look-up tables and a third multiplexer coupled to outputs of said first and second multiplexers, the method further comprising:

controlling said first and second multiplexers with one of said m input bits; and

controlling said third multiplexer with a second of said m input bits.