Secured signal modification and verification with privacy control

• US 7,100,050 B1
• Filed: 05/15/2000
• Issued: 08/29/2006
• Est. Priority Date: 04/13/1998
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Wu, Chai Wah, Tresser, Charles P., Mintzer, Frederick C., Weber, Samuel M., Yeung, Minerva Ming-Yee, Coppersmith, Don
• Primary Examiner(s): Moise, Emmanuel L.
• Assistant Examiner(s): PYZOCHA, MICHAEL J
• Application Number:
  US09/571,359
• Time in Patent Office: 2,297 Days
• Field of Search: 713/176, 380/201
• US Class Current: 713/176
• CPC Class Codes: G06T 1/0064 Geometric transfor invariant watermarking, e.g. affine transform invariant
• 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 1/32213 Modulating the least significant bits of pixels
• CPC Class Codes: H04N 1/32309 in colour image data
• CPC Class Codes: H04N 21/23892 involving embedding information at multiplex stream level, e.g. embedding a watermark at packet level
• CPC Class Codes: H04N 21/8358 involving watermark protecting executable software by watermarking G06F21/16; image watermarking in general G06T1/0021; watermarks inserted in still images for transmission purposes H04N1/32144; inserting watermarks during video coding H04N19/467
• CPC Class Codes: H04N 2201/3214 of a date
• CPC Class Codes: H04N 2201/3215 of a time or duration
• CPC Class Codes: H04N 2201/3225 of data relating to an image, a page or a document
• CPC Class Codes: H04N 2201/3226 of identification information or the like, e.g. ID code, index, title, part of an image, reduced-size image
• CPC Class Codes: H04N 2201/3233 of authentication information, e.g. digital signature, watermark
• CPC Class Codes: H04N 2201/3235 Checking or certification of the authentication information, e.g. by comparison with data stored independently
• CPC Class Codes: H04N 2201/327 which are undetectable to the naked eye, e.g. embedded codes

Abstract

A watermarking scheme is provided that allows the watermarked image to be authenticated by an authentication agent without revealing the human-readable content of the image. There is disclosed an approach that combines privacy control with watermarking and authentication mechanisms. The watermark can be made to be imperceptible to humans. Public key cryptography allows the authentication agent to authenticate without being able to watermark an image. Watermark information may also be encoded in a vector graphics image that includes at least one stroke defined by coordinate values of an ordered sequence of points. This may be obtained by providing watermark information as a bit sequence, identifying one or more redundant properties of the image, modifying the redundant properties based upon the bit sequence to generate a representation of the image and storing the representation of the image for subsequent use.

Claims

1. A method for using watermarks to distribute and authenticate human perceptible source data sets, comprising;

digitizing and segmenting a human perceptible source data set into a plurality of non-overlapping digitized segments and a corresponding plurality of overlapping digitized segments, wherein;

each non-overlapping segment is embedded within its corresponding overlapping segment in the same manner, and

said digitizing comprises a digital representation of said human perceptible source data set, and digital representation including digital elements, each said element being divided into high order bits and low order bits, said high order bits being sufficient to preserve the human perceptibility of said source data set;

creating a watermarked version of said source data set, wherein said creating a watermarked version of said source data set comprises, for each of said plurality of corresponding segments;

adding privacy control to said high order bits of said overlapping segment, resulting in a data set including encrypted high order bits;

applying a watermarked algorithm to said data set including encrypted high order bits, said algorithm resulting in a data set reduced in size;

mapping said reduced data set onto the low order bits of said non-overlapping segment, thereby replacing said low order bits, said reduction in size being sufficient such that said mapping results in spare low order bits being left over, some of said spare low order bits being used to indicate watermark attributes, wherein said mapping modifies a portion of said low order bits, said portion being adjustable downward to achieve higher fidelity and adjustable upward to achieve higher security;

distributing said watermarked data set;

applying a privacy release algorithm to said watermarked data set; and

authenticating said watermarked data set, wherein said authenticating is performed on a cropped portion of said watermarked data set, said watermark attributes being used to align said over-lapping segments.

2. A method for using watermarks to distribute and authenticate human perceptible source data sets, comprising:

digitizing and segmenting a human perceptible source data set into a plurality of non-overlapping digitized segments and a corresponding plurality of overlapping digitized segments, wherein;

each non-overlapping segment is embedded within its corresponding overlapping segment in the same manner, and

said digitizing comprises a digital representation of said human perceptible source data set, said digital representation including digital elements, each said element being divided into high order bits and low order bits, said high order bits being sufficient to preserve the human perceptibility of said source data set;

creating a watermarked version of said source data set wherein said creating a watermarked version of said source data set comprises, for each of said plurality of corresponding segments;

adding privacy control to said high order bits of said overlapping segment, resulting in a data set including encrypted high order bits;

applying a watermarking algorithm to said data set including encrypted high order bits, said algorithm resulting in a data set reduced in size;

mapping said reduced data set onto the low order bits of said non-overlapping segment, thereby replacing said low order bits, said reduction in size being sufficient such that said mapping results in spare low order bits being left over, some of said spare low order bits being used to indicate watermark attributes, wherein said mapping modifies a portion of said low order bits, said portion being adjustable downward to achieve higher fidelity and adjustable upward to achieve higher security;

distributing said watermarked data set;

applying a privacy release algorithm to said watermarked data set; and

authenticating said watermarked data set, wherein said authenticating is performed on a cropped portion of said watermarked data set, and wherein a small fixed synchronization pattern is embedded in said spare low order its for use in aligning said overlapping segments.

3. An apparatus for using watermarks to distribute and authenticate human perceptible source data sets, comprising:

means for digitizing and segmenting a human perceptible source data set into a plurality of non-overlapping digitized segments and a corresponding plurality of overlapping digitized segments, wherein;

each non-overlapping segment is embedded within its corresponding overlapping segment in the same manner, and

said digitizing means comprises a digital representation of said human perceptible source data set, said digital representation including digital elements, each said element being divided into high order bits and low order bits, said high order bits being sufficient to preserve the human perceptibility of source data set;

means for creating a watermarked version of said source data set, wherein said means for creating a watermarked version of said source data set comprises, for each of said plurality of corresponding segments;

means for adding privacy control to said high order bits of said overlapping segment, resulting in a data set including encrypted high order bits;

means for applying a watermarking algorithm to said data set including encrypted high order bits, said algorithm resulting in a data set reduced in size; and

means for mapping said reduced data set onto the low order bits of said non-overlapping segment, thereby replacing said low order bits, said reduction in size being sufficient such that said mapping results in spare low order bits being left over, some of said spare low order bits being used to indicate watermark attributes, wherein said mapping means modifies a portion of said low order bits, said portion being adjustable downward to achieve higher fidelity and adjustable upward to achieve higher security,

means for distributing said watermarked data set;

means for applying a privacy release algorithm to said watermarked data set; and

means for authenticating said watermarked data set, wherein said authenticating means operates on a cropped portion of said watermarked data set, said watermark attributes being used to align said over-lapping segments.

4. An apparatus for using watermarks to distribute and authenticate human perceptible source data sets, comprising;

means for digitizing and segmenting a human perceptible source data set into a plurality of non-overlapping digitized segments and a corresponding plurality of overlapping digitized segments, wherein;

each non-overlapping segment is embedded within its corresponding overlapping segment in the same manner, and

said digitizing means comprises a digital representation of said human perceptible source data set, said digital representation including digital elements, each said element being divided into high order bits and low order bits said high order bits being sufficient to preserve the human perceptibility of said source data set;

means for creating a watermarked version of said source data set, wherein said means for creating a watermarked version of said source data set comprises, for each of said plurality of corresponding segments;

means for adding privacy control to said high order bits of said overlapping segment, resulting in a data set including encrypted high order bits;

means for applying a watermarking algorithm to said data set including encrypted high order bits, said algorithm resulting in a data set reduced in size; and

means for mapping said reduced data set onto the low order bits of said non-overlapping segment, thereby replacing said low order bits, said reduction in size being sufficient such that said mapping results in spare low order bits being left over, some of said spare low order bits being used to indicate watermark attributes, wherein said mapping means modifies a portion of said low order bits, said portion being adjustable downward to achieve higher fidelity and adjustable upward to achieve higher security,

means for distributing said watermarked data set;

means for applying a privacy release algorithm to said watermarked data set; and

means for authenticating said watermarked data set, wherein said authenticating means operates on a cropped portion of said watermarked data set, and wherein a small fixed synchronization pattern is embedded in said spare low order bits for use in aligning said over-lapping segments.