Information signal transmission system

• US 5,682,425 A
• Filed: 03/06/1995
• Issued: 10/28/1997
• Est. Priority Date: 04/23/1990
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Enari, Masahiko
• Primary Examiner(s): Buczinski, Stephen C.
• Application Number:
  US08/398,815
• Time in Patent Office: 967 Days
• Field of Search: 380/10, 380/20, 380/21, 380/29, 380/37, 380/48
• US Class Current: 380/216
• CPC Class Codes: H04L 2209/122 Hardware reduction or efficient architectures
• CPC Class Codes: H04L 2209/125 Parallelization or pipelining, e.g. for accelerating processing of cryptographic operations
• CPC Class Codes: H04L 2209/30 Compression, e.g. Merkle-Damgard construction
• 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
• CPC Class Codes: H04N 7/1675 Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58

Abstract

The information signal transmission system of the present invention is so designed as to convert the analog information signal into digital information data and to transmit these digital data after enciphering a part of the digital data. It can therefore maintain the secrecy of the transmitted information signal and can employ a low-speed enciphering process, thereby reducing the magnitude of hardware and reducing its cost.

Claims

1. An information transmission device for transmitting digital information comprising:

A) input means for inputting digital information data;

B) data compression means for applying a data compressing process to the digital information data input from said input means, thereby forming compressed data;

C) encrypting means for encrypting and outputting only data of a portion of the compressed data formed by said data compression means and for outputting data of the remaining portion of said compressed data without encrypting; and

D) transmission means for transmitting the compressed data output from said encrypting means.

2. A system according to claim 1, further comprising:

A) data separation means for receiving the compressed data transmitted by said transmission means and for separating the received compressed data into encrypted compressed data and unencrypted compressed data;

B) decrypting means for decrypting the encrypted compressed data separated by said data separation means to decode original compressed data and for outputting the decoded compressed data; and

C) decoding means for decoding original digital information data from the decoded compressed data output from said deciphering means and the unciphered compressed data separated by said data separation means.

6. A system according to claim 1, wherein said data compression means includes block encoder means for block encoding the digital information data converted by said converter means thereby outputting block encoded data.

3. An information signal transmission device for transmitting an information signal, comprising:

A) input means for inputting a digital information data;

B) predictive encoder means for predictive encoding the digital information data input from said input means and for outputting predictive encoded data;

C) data output means for selectively outputting the digital information data input from said input means and the predictive encoded data output from said predictive encoder means, at a predetermined cycle;

D) encrypting means for encrypting data of a portion of the data output from said data output means; and

E) transmission means for transmitting the data the portion of which is encrypted by said encrypting means.

4. A device according to claim 3, wherein said encrypting means includes:

a) a data dividing circuit for dividing the data released from said data output means into the digital information data and the predictive encoded data;

b) an encrypting circuit for encrypting the digital information data divided by said data dividing circuit; and

c) a synthesizing circuit for synthesizing the data encrypted by said encrypting circuit and the unencrypted prediction encoded data divided by said data dividing circuit.

5. A device according to claim 4, further comprising:

A) data separation means for separating the data, transmitted by said transmission means, into the digital information data encrypted by said encrypting means and the unencrypted prediction encoded data;

B) decrypting means for decrypting the encrypted digital information data separated by said data separating means, thereby restoring the original digital information data; and

C) decoder means for restoring the original digital information data, utilizing the digital information data restored in said decrypting means and the unencrypted prediction encoded data separated by said data separation means.

7. An information signal transmission system for transmitting an information signal, comprising:

A) converter means for converting an analog information signal into digital information data;

B) dynamic range data detection means for receiving digital information data converted by said converter means by a predetermined data amount, and for outputting dynamic range data representing a dynamic range of the level represented by the received data of the predetermined amount;

C) representative value data forming means for quantizing the dynamic range of the data of said predetermined amount, determined by the dynamic range data outputted from said dynamic range data detection means, and for outputting representative value data corresponding to the levels of respective data in the data of said predetermined amount, among plural representative value data respectively representing different quantizing levels; and

D) data output means for outputting, in succession, the dynamic range data released from said dynamic range data detecting means and the representative value data output from said representative data forming means.

8. A system according to claim 7, wherein said enciphering means includes:

a) a data dividing circuit for dividing the data output from said data output means into said dynamic range data and said representative value data;

b) an enciphering circuit for enciphering the dynamic range data divided by said data dividing circuit; and

c) a synthesizing circuit for synthesizing the data enciphered by said enciphering circuit and the unciphered representative value data divided by said data dividing circuit.

9. A system according to claim 8, further comprising:

A) data separation means for separating the data, transmitted by said transmission means, into the dynamic range data enciphered by said enciphering means and the unciphered representative value data;

B) deciphering means for deciphering the enciphered dynamic range data separated by said data separation means, thereby restoring the original dynamic range data; and

C) decoder means for restoring the original digital information data, utilizing the dynamic range data restored in said deciphering means and the unciphered representative value data separated by said data separation means.

10. An information signal transmission system for transmitting an information signal, comprising:

A) converter means for converting an analog information signal into digital information data;

B) maximum value data detection means for receiving the digital information data converted by said converter means, by a predetermined data amount, and for outputting maximum value data representing the maximum value among the received data of the predetermined amount

C) minimum value data detection means for receiving the digital information data converted by said converter means, by a predetermined data amount, and for outputting minimum value data representing the minimum value among the received data of the predetermined amount,

D) representative value data forming means for quantizing the dynamic range of the data of said predetermined amount, determined by the maximum value data output from said maximum value data detection means and the minimum value data output from said minimum value data detection means, and for outputting representative value data corresponding to the levels of respective data in the data of said predetermined amount, among plural representative value data respectively representing different quantization levels; and

E) data output means for outputting, in succession, the maximum value data output from said maximum value data detection means, the minimum value data output from said minimum value data detection means, and the representative value data output from said representative value data forming means;

(F) enciphering means for enciphering data of a portion of the data output from said data output means; and

(G) transmission means for transmitting the data the portion of which is enciphered by said enciphering means.

11. A system according to claim 10, wherein said enciphering means includes:

a) a data dividing circuit for dividing the data, output from said data output means, into said maximum value data, said minimum value data, and said representative value data;

b) an enciphering circuit for enciphering the maximum value data divided by said data dividing circuit; and

c) a synthesizing circuit for synthesizing the data enciphered by said enciphering circuit, and the unciphered minimum value data and representative value data divided by said data dividing circuit.

12. A system according to claim 11, further comprising:

A) data separation means for separating the data, transmitted by said transmission means, into the maximum value data enciphered by said enciphering means, and the unciphered minimum value data and representative value data;

B) deciphering means for deciphering the enciphered maximum value data separated by said data separation means, thereby restoring the original maximum value data; and

C) decoder means for restoring the original digital information data, utilizing the maximum value data restored by said deciphering means, and the unciphered minimum value data and representative values data separated by said data separation means.

13. A system according to claim 10, wherein said enciphering means includes:

a) a data dividing circuit for dividing the data, released from said data output means, into said maximum value data, said minimum value data and said representative value data;

b) an enciphering circuit for enciphering the minimum value data divided by said data dividing circuit; and

c) a synthesizing circuit for synthesizing the data enciphered by said enciphering circuit, and the unciphered maximum value data and representative value data divided by said data dividing circuit.

14. A system according to claim 13, further comprising:

A) data separation means for separating the data, transmitted by said transmission means, into the minimum value data enciphered by said enciphering means, and the unciphered maximum value data and representative value data;

B) deciphering means for deciphering the enciphered minimum value data separated by said data separation means, thereby restoring the original minimum value data; and

C) decoder means for restoring the original digital information data, utilizing the minimum value data restored by said deciphering means, and the unciphered maximum value data and representative value data separated by said data separation means.

15. A digital image data transmission device for transmitting digital image data, comprising:

data processing means for receiving the digital image data and encrypting a part of the digital image data to output the encrypted portion and the unencrypted portion of the digital image data, the encrypted portion of the digital image data corresponding to a major portion of the digital image data; and

data transmission means for transmitting the digital information data output from said data processing means.

16. A device according to claim 15, wherein said data processing means includes data conversion means for converting the received digital image data into digital image data of n bits (n is an integer equal to or greater than 2) and outputting the converted digital information data.

17. A device according to claim 16, wherein said data processing means further includes:

data division means for receiving the digital image data output from said data conversion means on the unit basis of n bits and dividing the received digital information data into data of k bits and data of (n-k) bits;

encrypting means for encrypting said data of k bits, output from said data division means and outputting the encrypted data; and

data synthesizing means for synthesizing the encrypted data output from said encrypting means and the unencrypted data of (n-k) bits, output from said data division mean and outputting the synthesized data.

18. A device according to claim 17, wherein said data division means is arranged so as to receive the digital image data output from said data conversion means on the basis of n bits, and to divide the received digital image data of n bits into upper k bits and lower (n-k) bits and output the divided bits.

19. A device according to claim 15, further comprising:

data separation means for receiving the digital image data transmitted by said data transmission means, separating the received digital information data into encrypted data and the unencrypted data and outputting the separated data;

decrypting means for decrypting the encrypted data output from said data separation means to decode original image data and outputting the decoded data; and

data synthesizing means for synthesizing the data output from said decrypting means and the unencrypted data output from said data separation means and outputting the synthesized data.

20. An information transmitting method, comprising the steps of:

a) inputting digital information data;

b) compressing the input digital information data to obtain compressed data;

c) encrypting a portion of the compressed data to obtain encrypted data; and

d) transmitting the remaining portion of the compressed data without encrypting and the encrypted data.

21. A method according to claim 20, wherein the digital information data is digital image data and the portion of the compressed data corresponds to a major portion of the compressed data.

22. A method according to claim 21, wherein the compressed data is obtained by compressing the digital image data in a unit of a block consisting of data corresponding to a plurality of pixels.

23. A method according to claim 22, wherein the major portion of the compressed data corresponds to a representative level of the block and the remaining portion of the compressed data corresponds to a detailed construction of the block.

24. A method according to claim 21, wherein the compressed data is obtained by compressing the digital image data using a predictive coding method.

25. A method according to claim 24, wherein the remaining portion of the compressed data includes differential data which represents a difference between an input image data and a predictive image data and the major portion of the compressed data does not include the differential data.

26. An image signal processing signal device comprising:

input means for inputting digital image data;

separation means for separating the input digital image data into a first portion and a second portion thereof;

encrypting means for encrypting the first portion of the digital image data to obtain encrypted data; and

output means for outputting the second portion of the digital image data without encrypting and the encrypted data.

27. A device according to claim 26, wherein the first portion includes data roughly representing an image corresponding to the input digital image data and the second portion includes data representing the image in detail.

28. A device according to claim 27, wherein said separation means separates the input digital image data on the unit of a block consisting of data of which corresponds to a plurality of pixels.

29. An image signal processing method, comprising the steps of:

inputting digital image data;

separating the input digital image data into a first portion and a second portion thereof;

encrypting the first portion of the digital image data to obtain encrypted data; and

outputting the second portion of the digital image data without encrypting and the encrypted data.

30. A method according to claim 29, wherein the first portion includes data roughly representing an image corresponding to the input digital image data and the second portion includes data representing the image in detail.

31. A method according to claim 30, wherein the input digital image data is separated into the first and second portions on the unit of a block consisting of data which corresponds to a plurality of pixels.