Transformation pattern generating device and encryption function device

• US 5,623,548 A
• Filed: 01/10/1995
• Issued: 04/22/1997
• Est. Priority Date: 01/10/1994
• Status: Expired due to Term

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Akiyama, Ryota, Iwayama, Noboru, Torii, Naoya, Utsumi, Kenichi
• Primary Examiner(s): CANGIALOSI, SALVATORE A
• Application Number:
  US08/370,881
• Time in Patent Office: 833 Days
• Field of Search: 380/28, 380/29, 380/48
• US Class Current: 380/28
• CPC Class Codes: H04L 2209/12 Details relating to cryptographic hardware or logic circuitry
• CPC Class Codes: H04L 9/002 Countermeasures against attacks on cryptographic mechanisms network architectures or network communication protocols for protection against malicious traffic H04L63/1441
• CPC Class Codes: H04L 9/0662 with particular pseudorandom sequence generator

Abstract

In accordance with the present invention, there is provided a transformation pattern generating mechanism comprising: a key input section for inputting a key for encryption; a transformation pattern generating section for generating a transformation pattern for transformation of input data; and an output section for outputting the generated transformation pattern; wherein, when a number sequence corresponding to a predetermined transformation pattern is input as the key to the key input section, said transformation pattern generating section generates and outputs the predetermined transformation pattern corresponding to the number sequence.

Claims

1. An encryption function device, comprising:

key input means for inputting a key for encryption;

transformation pattern generating means for using the key as a key number sequence and for generating a transformation pattern using at least one of the key number sequence and a pseudo-random number sequence generated by a random number generator using the key number sequence as a seed; and

transformation means for transforming data in accordance with the transformation pattern generated by said transformation pattern generating means,

wherein the transformation pattern includes m substitution tables and a permutation circuit having m input terminals and m output terminals,

wherein said transformation means includes;

m input switches, where m is an even number;

m output destination switches;

m exclusive-OR circuits; and

a bit rotate shift mechanism having m input terminals and m output terminals; and

wherein a j-th input switch in one switching state outputs a j-th mini-block which is one of m mini-blocks into which input data is divided, and the j-th input switch in another switching state outputs a mini-block sent from a j-th output destination switch;

the j-th output destination switch in one switching state outputs the j-th mini-block of the bit rotate shift means, and the j-th output destination switch in another switching state outputs the j-th mini-block of the bit rotate shift means to the j-th input switch;

an output of a k-th input switch is input to an address of a k-th substitution table, where k is between 1 and m/2;

an output of the k-th substitution table and an output of an (i+k-1)-th substitution table are input to a k-th exclusive-OR-circuit;

an output of an (i+k-1)-th exclusive-OR circuit is input to an address of the (i+k-1)-th substitution table;

an output of an (i+k-1)-th input switch and the output of the k-th substitution table are input to the (i+k-1)-th exclusive-OR circuit;

an output of the k-th exclusive-OR circuit is input to a k-th input terminal of the permutation circuit;

the output of the (i+k-1)-th substitution table is applied to an (i+k-1)-th input terminal of the permutation circuit;

a j-th output of the permutation circuit is input to a j-th input terminal of the bit rotation shift means; and

the bit rotate shift means rotatively shifts entire data input to first to m-th input terminals.

2. An encryption function device as claimed in claim 1, wherein contents of the m substitution tables are changed in accordance with the at least one of the key number sequence and the pseudo-random number sequence.

3. An encryption function device as claimed in claim 1, wherein a permutation mode of the permutation circuit is changed in accordance with the at least one of the key number sequence and the pseudo-random number sequence.

5. An encryption function device of claim 1, wherein a shift amount of the bit rotation shift means is changed in accordance with the at least one of the key number sequence and the pseudo-random number sequence.

6. An encryption function device of claim 2, wherein a shift amount of the bit rotation shift means is changed in accordance with the at least one of the key number sequence and the pseudo-random number sequence.

7. An encryption function device of claim 3, wherein a shift amount of the bit rotation shift means is changed in accordance with the at least one of the key number sequence and the pseudo-random number sequence.

9. An encryption function device of claim 1, wherein the number of times of feeding back data from the m output destination switches to the m input switches is changed in accordance with the at least one of the key number sequence and the pseudo-random number sequence.

10. An encryption function device of claim 2, wherein the number of times of feeding back data from the m output destination switches to the m input switch is changed in accordance with the at least one of the key number sequence and the pseudo-random number sequence.

11. An encryption function device of claim 3, wherein the number of times of feeding back data from the m output destination switches to the m input switch is changed in accordance with the at least one of the key number sequence and the pseudo-random number sequence.

13. An encryption function device of claim 5, wherein the number of times of feeding back data from the m output destination switches to the m input switch is changed in accordance with the at least one of the key number sequence and the pseudo-random number sequence.

14. An encryption function device of claim 6, wherein the number of times of feeding back data from the m output destination switches to the m input switch is changed in accordance with the at least one of the key number sequence and the pseudo-random number sequence.

15. An encryption function device of claim 7, wherein the number of times of feeding back data from the m output destination switches to the m input switch is changed in accordance with the at least one of the key number sequence and the pseudo-random number sequence.

4. An encryption function device as claimed in 2, wherein a permutation mode of the permutation circuit is changed in accordance with the at least one of the key number sequence and the pseudo-random number sequence.

8. An encryption function device of claim 4, wherein a shift amount of the bit rotation shift means is changed in accordance with the at least one of the key number sequence and the pseudo-random number sequence.

12. An encryption function device of claim 4, wherein the number of times of feeding back data from the m output destination switches to the m input switch is changed in accordance with the at least one of the key number sequence and the pseudo-random number sequence.

16. An encryption function device of claim 8, wherein the number of times of feeding back data from the m output destination switches to the m input switch is changed in accordance with the at least one of the key number sequence and the pseudo-random number sequence.