Method for cryptographic transformation of binary data blocks

• US 20050147244A1
• Filed: 12/30/2003
• Published: 07/07/2005
• Est. Priority Date: 12/30/2003
• Status: Abandoned Application

• Current Assignee: Alexander Moldovyan, Nikolai Moldovyan
• Original Assignee: Alexander Moldovyan, Nikolai Moldovyan
• Inventors: Moldovyan, Alexander, Moldovyan, Nikolai
• Application Number:
  US10/747,135
• Publication Number:
  US 20050147244A1
• Time in Patent Office: Days
• US Class Current: 380/29
• CPC Class Codes: H04L 2209/24 Key scheduling, i.e. generating round keys or sub-keys for block encryption
• CPC Class Codes: H04L 9/0631 Substitution permutation network [SPN], i.e. cipher composed of a number of stages or rounds each involving linear and nonlinear transformations, e.g. AES algorithms
• CPC Class Codes: H04L 9/0643 Hash functions, e.g. MD5, SHA, HMAC or f9 MAC
• CPC Class Codes: H04L 9/50 using hash chains, e.g. blockchains or hash trees

Abstract

A method for cryptographic transformation of a binary data block comprising the steps splitting said data block into N≧2 sub-blocks, alternately converting said sub-blocks by the operations implemented with a controlled substitution-permutation network (CSPN), and performing a controlled CSPN-based involution on at least the i-th sub-block, where i=1, 2, . . . , N. A ciphering/deciphering device is also provided.

Claims

1. A method for cryptographic transformation of a binary data block comprising the steps:

splitting said data block into N≧

2 sub-blocks,

alternately converting said sub-blocks by operations implemented with a controlled substitution-permutation network (CSPN), and

performing a controlled CSPN-based involution on at least the i-th sub-block, where i=1, 2, . . . ,N.

2. A method according to claim 1, wherein the controlled CSPN-based involution is a controlled permutational involution.

3. A method according to claim 1, wherein the controlled CSPN-based involution is a controlled substitutional involution.

4. A method according to claim 1, wherein N=2 and the first sub-block is converted with a direct controlled CSPN-based operation depending on the second sub-block, the second sub-block is converted with the controlled CSPN-based involution depending on the first sub-block, and the first sub-block is converted with the inverse controlled CSPN-based operation depending on the second sub-block.

5. A method according to claim 1, wherein N=2 and the first and the second sub-blocks are transformed simultaneously by performing on the first sub-block the direct controlled CSPN-based operation implemented with CSPN depending on the second sub-block and by performing on the second sub-block the controlled CSPN-based involution depending on the second sub-block, and then the first sub-block is converted with the inverse controlled operation implemented with CSPN depending on the second sub-block.

6. Encryption method comprising a cryptographic transformation of binary data blocks according to the method of claim 1.

7. Decryption method comprising a cryptographic transformation of binary data blocks according to the method of claim 1.

8. Method for calculating a hash sum comprising a cryptographic transformation of binary data blocks according to the method of claim 1.

9. Ciphering device arranged to perform a cryptographic transformation of binary data blocks according to the method of claim 1.

10. Deciphering device arranged to perform a cryptographic transformation of binary data blocks according to the method of claim 1.

11. Communications network wherein ciphering and/or deciphering comprises performing a cryptographic transformation of binary data blocks according to the method of claim 1.

12. Terminal in a communications network wherein ciphering and/or deciphering comprises performing a cryptographic transformation of binary data blocks according to the method of claim 1.