Security enhancements of digital watermarks for multi-media content

Abstract

Methods and apparatus for embedding digital watermarks into a digital host content are provided. A digital host content is received, e.g., at a receiver or other device incorporating a receiver. One or more watermark embedding technologies is selected. Multiple embedding opportunities are identified within the host content. A subset of the identified embedding opportunities is selected. A multiplicity of digital watermarks are then embedded into the host content in accordance with the selected subset of embedding opportunities utilizing the one or more selected watermark embedding technologies. The selecting of the subset of embedding opportunities may be adapted to provide a desired tradeoff between levels of robustness, security, and transparency of the watermark. A plurality of watermarking embedding technologies may be selected and used in the embedding step.

1 . A method for embedding digital watermarks into a digital host content, comprising: 
 receiving a digital host content;    selecting one or more watermark embedding technologies;    identifying multiple embedding opportunities within said host content;    selecting a subset of said identified embedding opportunities; and    embedding a multiplicity of digital watermarks into the host content in accordance with said selected subset of embedding opportunities utilizing said one or more selected watermark embedding technologies.    
   
   
       2 . The method of  claim 1 , wherein said host content comprises one of multimedia content, audio content, video content, audiovisual content, or image content.  
   
   
       3 . The method of  claim 1 , wherein said selecting of said subset of embedding opportunities is adapted to provide at least one of optimum robustness, optimum security and optimum transparency of the watermark.  
   
   
       4 . The method of  claim 1 , wherein said selecting of said subset of embedding opportunities is adapted to provide a desired tradeoff between levels of robustness, security, and transparency of the watermark.  
   
   
       5 . The method of  claim 1 , wherein a plurality of watermarking embedding technologies are selected and used in said embedding step.  
   
   
       6 . The method of  claim 1 , wherein at least two different watermarking embedding technologies are selected and used in said embedding step.  
   
   
       7 . The method of  claim 1 , wherein said embedding opportunities are identified in accordance with characteristics of the host content.  
   
   
       8 . The method of  claim 7 , wherein said characteristics comprise at least one of temporal frequency, spatial frequency, duration, peak amplitude, luminance, chrominance or masking capability of the content.  
   
   
       9 . The method of  claim 1 , wherein said embedding opportunities are identified in accordance with parameters of the watermark embedding technologies.  
   
   
       10 . The method of  claim 9 , wherein said parameters comprise at least one of autocorrelation delay, frequency shift, PN sequence, quantization index, strength of embedding, chip rate, or embedding bit rate.  
   
   
       11 . The method of  claim 1 , wherein said embedding opportunities are identified in accordance with both characteristics of the host content and parameters of the watermark embedding technologies.  
   
   
       12 . The method of  claim 1 , wherein said embedding opportunities comprise a multi-dimensional space.  
   
   
       13 . The method of  claim 12 , wherein the dimensions of said space are comprised of at least two of: temporal frequency band, spatial frequency band, time segment, spatial extent, time delay, frequency shift, PN sequence, or embedding algorithm type.  
   
   
       14 . The method of  claim 1 , wherein said multiplicity of watermarks are embedded using the same selected watermark embedding technology but with different embedding parameters.  
   
   
       15 . The method of  claim 1 , wherein an extent of said selected embedding opportunities is determined in accordance with at least one of desired transparency, robustness, or security of the system.  
   
   
       16 . The method of  claim 1 , wherein a different subset of the identified embedding opportunities is selected for embedding each host content.  
   
   
       17 . The method of  claim 16 , wherein said different subsets have no common elements.  
   
   
       18 . The method of  claim 16 , wherein said different subsets have at least one common element.  
   
   
       19 . The method of  claim 1 , wherein different subsets of embedding opportunities are selected for embedding different copies of the same host content.  
   
   
       20 . The method of  claim 19 , wherein said different subsets have no common elements.  
   
   
       21 . The method of  claim 19 , wherein said different subsets have at least one common element.  
   
   
       22 . The method of  claim 1 , wherein said subset of embedding opportunities is selected at random.  
   
   
       23 . The method of  claim 1 , wherein said identifying step produces a different number of embedding opportunities for different implementations of an embedding device.  
   
   
       24 . The method of  claim 1 , wherein a pattern of selected embedding opportunities uniquely identifies each embedding device.  
   
   
       25 . The method of  claim 1 , wherein a pattern of selected embedding opportunities uniquely identifies each embedding.  
   
   
       26 . The method of  claim 1 , wherein said selecting of said subset of said identified embedding opportunities is adaptable in response to observed or anticipated attacks.  
   
   
       27 . The method of  claim 1 , wherein the selecting of said subset of said identified embedding opportunities comprises: 
 selecting at least one type of attack available against the selected watermark embedding technology; and    producing a first set of embedding opportunities that are adapted to be transformed into a second set of embedding opportunities in the presence of said attack.    
   
   
       28 . Apparatus for embedding digital watermarks into a digital host content, comprising: 
 a receiver for receiving a digital host content;    means for selecting one or more watermark embedding technologies;    identification means for identifying multiple embedding opportunities within said host content;    a selector means for selecting a subset of said identified embedding opportunities; and    an embedder for embedding a multiplicity of digital watermarks into the host content in accordance with said selected subset of embedding opportunities utilizing said one or more selected watermark embedding technologies.    
   
   
       29 . A method for extracting digital watermarks from a digital host content, comprising: 
 receiving a digital host content;    selecting at least one stego key from a collection of stego keys; and    extracting the embedded watermarks from the host content in accordance with said selected stego key(s).    
   
   
       30 . The method of  claim 29 , wherein said selecting of said at least one stego key is adapted to produce at least one of optimum robustness, security, and computational efficiency for the extraction of watermarks embedded in the host content.  
   
   
       31 . The method of  claim 29 , wherein said selecting of said at least one stego key is adapted to produce a desired tradeoff between levels of robustness, security, and computational efficiency for the extraction of watermarks embedded in the host content.  
   
   
       32 . The method of  claim 29 , wherein said selecting of said at least one stego key comprises selecting at least one stego key in a random fashion.  
   
   
       33 . The method of  claim 29 , wherein the collection of stego keys comprises one stego key.  
   
   
       34 . The method of  claim 29 , wherein the collection of stego keys comprises at least two stego keys.  
   
   
       35 . The method of  claim 29 , wherein the collection of stego keys comprises at least a pair of stego keys with no common elements.  
   
   
       36 . The method of  claim 29 , wherein the collection of stego keys comprises at least a pair of stego keys with at least one common element.  
   
   
       37 . The method of  claim 29 , further comprising reporting the presence and value of extracted watermarks at pre-determined time intervals.  
   
   
       38 . The method of  claim 29 , wherein said selecting of said one or more stego keys is adapted in accordance with a desired false positive detection rate.  
   
   
       39 . The method of  claim 29 , wherein said selecting of said one or more stego keys is adapted to produce a desired probability of successful extractions.  
   
   
       40 . The method of  claim 29 , wherein said selecting of said one or more stego keys is adapted to produce a desired computational complexity for the extraction of watermarks.  
   
   
       41 . The method of  claim 29 , wherein said selecting of said one or more stego keys is adapted to anticipate transformations of the host content.  
   
   
       42 . The method of  claim 41 , wherein said transformations modify watermark characteristics.  
   
   
       43 . The method of  claim 41 , wherein said transformations alter the appearance of at least one watermark that is embedded with a first embedding stego key such that the at least one embedded watermark appears to have been embedded with a second embedding stego key.  
   
   
       44 . The method of  claim 29 , wherein a size of a selected stego key varies from one host content to another.  
   
   
       45 . The method of  claim 29 , wherein a size of said collection of stego keys varies in accordance with a type or value of the host content.  
   
   
       46 . The method of  claim 29 , wherein a size of a selected stego key varies in accordance with a type or value of the host content.  
   
   
       47 . The method of  claim 29 , wherein the collection of stego keys comprises a subset of all possible extraction stego keys.  
   
   
       48 . The method of  claim 29 , wherein the collection of stego keys is adapted in accordance with an observed or anticipated attack.  
   
   
       49 . The method of  claim 29 , wherein the collection of stego keys is adapted in accordance with an expiration date.  
   
   
       50 . An apparatus for extracting digital watermarks from a digital host content, comprising: 
 a receiver for receiving a digital host content;    a memory device for storing a collection of stego keys;    a selection means for selecting at least one stego key from the collection of stego keys; and    an extraction device for extracting the embedded watermarks from the host content in accordance with said selected stego key(s).    
   
   
       51 . A method for embedding and extracting of digital watermarks from digital host content, comprising: 
 receiving digital host content;    identifying multiple embedding opportunities within said host content;    selecting a first subset of said identified embedding opportunities within said host content;    embedding a multiplicity of digital watermarks into the host content in accordance with said selecting of said first subset to produce a composite host content;    transmitting the composite host content to one or more reception means;    receiving the composite host content;    selecting at least one stego key from a collection of stego keys; and    extracting the embedded watermarks from the composite host content in accordance with said at least one stego key.    
   
   
       52 . The method of  claim 51 , wherein said selecting of the first subset of identified embedding opportunities is conducted in a pseudo-random fashion.  
   
   
       53 . The method of  claim 51 , wherein the selecting of the at least one stego key is conducted in a pseudo-random fashion.  
   
   
       54 . The method of  claim 51 , wherein the selecting of the subset of identified embedding opportunities and the selecting of the at least one stego key for extraction of the embedded watermarks are adapted to produce at least one of optimum security, robustness, transparency, and computational efficiency at a given false positive extraction rate.  
   
   
       55 . The method of  claim 51 , wherein the selecting of the subset of identified embedding opportunities and the selecting of the at least one stego key for extraction of the embedded watermarks are adapted to produce a desired tradeoff between levels of robustness, security, and computational efficiency for the embedding and extraction of watermarks.  
   
   
       56 . The method of  claim 51 , wherein the selecting of the subset of identified embedding opportunities and the selecting of the at least one stego key for extraction of the embedded watermarks are adapted to optimize at least two of: 
 security,    robustness,    transparency,    computational efficiency, or    false positive extraction rate.    
   
   
       57 . The method of  claim 51 , wherein extraction of a subset of all originally embedded watermarks are enabled in accordance with the at least one stego key.  
   
   
       58 . The method of  claim 51 , wherein extraction of all possibly embedded watermarks are enabled in accordance with the at least one stego key.  
   
   
       59 . A system for embedding and extracting of digital watermarks from digital host content, comprising: 
 a receiver for receiving digital host content;    identification means for identifying multiple embedding opportunities within said host content;    a selector means for selecting a first subset of said identified embedding opportunities within said host content;    an embedder for embedding a multiplicity of digital watermarks into the host content in accordance with said selecting of said first subset to produce a composite host content;    a transmitter for transmitting the composite host content to one or more reception means;    reception means for receiving the composite host content;    a selector means for selecting at least one stego key from a collection of stego keys; and    extraction means for extracting the embedded watermarks from the composite host content in accordance with said at least one stego key.