Shifting an encryption key in either a first or second direction via a uni-directional shifting unit

• US 20030235298A1
• Filed: 06/25/2002
• Published: 12/25/2003
• Est. Priority Date: 06/25/2002
• Status: Abandoned Application

• Current Assignee: LSI Corporation (Broadcom, Inc.)
• Original Assignee: LSI Corporation (Broadcom, Inc.)
• Inventors: Hanounik, Bedros
• Application Number:
  US10/179,862
• Publication Number:
  US 20030235298A1
• Time in Patent Office: Days
• US Class Current: 380/29
• CPC Class Codes: H04L 2209/122 Hardware reduction or efficient architectures
• 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

According to some embodiments, an encryption key is shifted in either a first or second direction via a uni-directional shifting unit.

Claims

1. An encryption device, comprising:

a first bit reversing unit adapted to receive an encryption key;

a uni-directional shifting unit adapted to receive information from the first bit reversing unit; and

a second bit reversing unit adapted to receive information from the uni-directional shifting unit.

2. The encryption device of claim 1, wherein the first and second bit reversing units can be disabled when the encryption key is shifted in a first direction and enabled when the encryption key is shifted in a second direction.

3. The encryption device of claim 2, wherein the encryption key is circularly shifted left when encrypting information and right when decrypting information.

4. The encryption device of claim 1, wherein the encryption device is implemented via at least one of:

(i) a field-programmable gate array, and (ii) an application specific integrated circuit.

5. The encryption device of claim 1, wherein the first bit reversing unit is adapted to receive the encryption key from a memory unit.

6. The encryption device of claim 1, wherein the first bit reversing unit is adapted to be used by a plurality of encryption engines.

7. The encryption device of claim 1, wherein the first bit reversing unit comprises a software application.

8. The encryption device of claim 1, wherein the uni-directional shifting unit is adapted to shift information either (i) a first number of bit positions or (ii) a second number of bit positions.

9. The encryption device of claim 8, wherein said encryption device is adapted to facilitate a multi-round encryption process, and the number of bit positions being shifted is based on the encryption round.

10. The encryption device of claim 1, wherein the second bit reversing unit is adapted to provide information to be used in an encryption process.

11. The encryption device of claim 10, wherein the encryption process includes an exclusive OR operation.

12. The encryption device of claim 11, wherein the second bit reversing unit comprises:

a multiplexer adapted to output one of a shifted encryption key bit and a reversed shifted encryption key bit based on a encrypt/decrypt control signal; and

an exclusive OR unit adapted to receive data and the output from the multiplexer.

13. The encryption device of claim 12, wherein the second bit reversing unit uses a single slice of a field-programmable gate array for each bit of an encryption key.

14. The encryption device of claim 13, wherein the second bit reversing unit comprises a look-up table.

15. The encryption device of claim 1, wherein the encryption device is associated with at least one of:

(i) generating a ciphertext output based on a plaintext input and an encryption key, (ii) generating a plaintext output based on a ciphertext input and a decryption key, (iii) a data encryption standard process, (iv) a triple data encryption standard process, and (v) an advanced encryption standard process.

16. An encryption device, comprising:

a uni-directional shifting unit; and

a bit reversing unit adapted to receive information from the uni-directional shifting unit.

17. The encryption device of claim 16, wherein the bit reversing unit uses a single slice of a field-programmable gate array for each bit of an encryption key and comprises:

a multiplexer adapted to output one of a shifted encryption key bit and a reversed shifted encryption key bit based on a encrypt/decrypt control signal; and

an exclusive OR unit adapted to receive data and the output from the multiplexer.

18. A method of facilitating an encryption process, comprising:

determining an encryption key; and

arranging for the encryption key to be shifted in either a first or a second direction via a uni-directional shifting unit.

19. The method of claim 18, wherein said arranging comprises:

if the encryption key is shifted in the first direction;

shifting bits in the encryption key via the uni-directional shifting unit; and

if the encryption key is shifted in the second direction;

reversing bits in an encryption key,

shifting the reversed bits via the uni-directional shifting unit, and

reversing the shifted bits.

20. A medium storing instructions adapted to be executed by a processor to perform a method of facilitating an encryption process, the method comprising:

determining an encryption key; and

arranging for the encryption key to be shifted in either a first or a second direction via a uni-directional shifting unit.

21. The medium of claim 20, wherein said arranging comprises:

if the encryption key is shifted in the first direction;

shifting bits in the encryption key via the uni-directional shifting unit; and

if the encryption key is shifted in the second direction;

reversing bits in an encryption key,

shifting the reversed bits via the uni-directional shifting unit, and

reversing the shifted bits.