System for embedding authentication information into an image and an image alteration detecting system

• US 6,005,936 A
• Filed: 08/25/1997
• Issued: 12/21/1999
• Est. Priority Date: 11/28/1996
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Numao, Masayuki, Shimizu, Shuichi, Morimoto, Norishige
• Primary Examiner(s): Gregory, Bernarr E.
• Application Number:
  US08/918,163
• Time in Patent Office: 848 Days
• Field of Search: 380/3, 380/4, 380/5, 380/9, 380/23, 380/25, 380/29, 380/30, 380/49, 380/50, 380/54, 380/59, 380/7, 380/10, 382/100, 382/232, 382/276, 382/325
• US Class Current: 713/176
• CPC Class Codes: G06T 1/0028 Adaptive watermarking, e.g. Human Visual System [HVS]-based watermarking
• CPC Class Codes: G06T 2201/0065 Extraction of an embedded watermark; Reliable detection
• CPC Class Codes: H04N 1/32144 embedded in the image data, i.e. enclosed or integrated in the image, e.g. watermark, super-imposed logo or stamp
• CPC Class Codes: H04N 2101/00 Still video cameras
• CPC Class Codes: H04N 2201/3233 of authentication information, e.g. digital signature, watermark
• CPC Class Codes: H04N 2201/3236 Details of authentication information generation
• CPC Class Codes: H04N 2201/327 which are undetectable to the naked eye, e.g. embedded codes
• CPC Class Codes: H04N 2201/3281 Encryption; Ciphering

Abstract

A digital camera for embedding authentication information to detect the identity of a photographed image into an image. By supplying the authentication information integrally with image data, the verifier is enabled to verify the image data without saving the authentication information. Particularly, by converting the light inputted through an optical system to an electric signal, a CCD outputs an analog signal of an image which is converted to a digital signal. In response to the digital signal of the image, a digital camera having a region dividing unit divides the digital image into first and second regions. Authentication information is generated from data in the first region, which information is then encrypted. The encrypted authentication information is embedded into the second image region. The first and second image regions are then combined.

Claims

1. A system for embedding authentication information into an image, said system comprising:

a region dividing unit for dividing the image into a first image region and a second image region;

an authentication information generating unit for generating

authentication information from data in said first image region;

a hiding unit for embedding said authentication information into said second image region by operating data in said second image region; and

a region combining unit for combining said first image region in said image with said second image region in which said authentication information is embedded.

2. A system as set forth in claim 1 wherein said authentication information is a digest of data in said first image region.

3. A system as set forth in claim 2 wherein said digest is a hash value of data in said first image region.

4. A system as set forth in claim 1 further comprising an encrypting unit for encrypting said authentication information, wherein said hiding unit embeds said encrypted authentication information into said second image region.

5. An image alteration detecting system comprising:

a region identifying unit for identifying a first image region and a second image region in an image, said second image region including information embedded by operating data;

an authentication information generating unit for generating first authentication information from data in said first image region;

an extracting unit for extracting second authentication information from said second image region; and

an alteration detecting unit for determining, if said first authentication information is the same as said second authentication information, that there is no alteration in said image.

6. A system as set forth in claim 5 wherein said alteration detecting unit determines, if said first authentication information is not the same as said second authentication information that there is alteration in said image.

7. A system as set forth in claim 6 wherein said digest is a hash value of data in said first image region.

8. A system as set forth in claim 5 wherein said first authentication information is a digest of data in said first image region.

9. A system as set forth in claim 5 wherein said second authentication information is encrypted information,

said system further comprising a decoding unit for decoding said second authentication information,

wherein said alteration detecting unit determines, if said decoded authentication information is the same as said first authentication information, that there is no alteration in said image.

10. A method for embedding authentication information into an image, said method comprising the steps of:

dividing the image into a first image region and a second image region;

generating authentication information from data in said first image region;

embedding said authentication information into said second image region by operating data in said second image region; and

combining said first image region in said image with said second image region in which said authentication information is embedded.

11. A method for detecting the identity of an image comprising the steps of:

identifying a first image region and a second image region in the image said second image region including information embedded by operating data in said second image region;

generating first authentication information from data in said first image region;

extracting second authentication information from said second image region; and

determining, if said first authentication information is the same as said second authentication information, that there is no alteration in said image.

12. A digital camera comprising:

an optical system;

a converter for converting the light inputted through said optical system to an electric signal so as to output an analog signal of an image;

a signal processing unit for generating a digital signal of the image in response to said analog signal;

a region dividing unit for dividing the image into a first image region and a second image region in response to said digital signal;

an authentication information generating unit for generating authentication information from data in said first image region;

an encrypting unit for encrypting said authentication information;

a hiding unit for embedding the encrypted authentication information into said second image region by operating data in said second image region; and

a region combining unit for combining said first image region in said image with said second image region in which said authentication information is embedded.

13. A digital camera as set forth in claim 12 wherein said authentication information is a hash value of data in said first image region.