Steganography and Digital Watermarking - Revision history

Ganv at 14:33, 12 April 2009

2009-04-12T14:33:17Z

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	Steganography is the method of concealing a message, and its		Steganography is the method of concealing a message, and its
-	very ~~existance~~ is a secret and only known to the person(s) who placed it. Historical steganography involved ~~dissapearing~~ inks and masking letters to hide the information. While modern steganography, information hiding involves hiding data in digital media where by slightly altering the media causes a message to be embedded without anyone noticing any loss to the actual media file. Since steganography is a form of "[http://en.wikipedia.org/wiki/Security_through_obscurity security through obscurity]", where it protects the messages and the known parties through secrecy, it is often combined with cryptography so that even if the message is found, it still cannot be read. <sup>[9]</sup>	+	very existence is a secret and only known to the person(s) who placed it. Historical steganography involved disappearing inks and masking letters to hide the information. While modern steganography, information hiding involves hiding data in digital media where by slightly altering the media causes a message to be embedded without anyone noticing any loss to the actual media file. Since steganography is a form of "[http://en.wikipedia.org/wiki/Security_through_obscurity security through obscurity]", where it protects the messages and the known parties through secrecy, it is often combined with cryptography so that even if the message is found, it still cannot be read. <sup>[9]</sup>

	<br><br><br><br><br><br><br>		<br><br><br><br><br><br><br>
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	== What is Digital Watermarking? ==		== What is Digital Watermarking? ==
	[[Image:cov2watermark.png\|right\|250px\|File displaying both visible and invisible watermarks]]		[[Image:cov2watermark.png\|right\|250px\|File displaying both visible and invisible watermarks]]
-	Digital watermarking is the process of embedding a symbol of some sort into the media file to distinguish the file from others. The ~~embbeded~~ watermark is meant to be ~~permenant~~ and follows a process in which there is alterations to the media file. Digital watermarking can be hidden or seen in plain sight by other parties. Deciding on whether to use visible/invisible watermarking depends on the function of the media file, but with either technique, when the media file is copied the digital watermark gets copied as well. Digital watermarks are designed in such a way that they do not restrict the media file or change the media file in such a way it detracts the quality. Its main purpose is to detect misuse and act as a form of signature from the owner. <sup>[5]</sup>	+	Digital watermarking is the process of embedding a symbol of some sort into the media file to distinguish the file from others. The embedded watermark is meant to be permanent and follows a process in which there is alterations to the media file. Digital watermarking can be hidden or seen in plain sight by other parties. Deciding on whether to use visible/invisible watermarking depends on the function of the media file, but with either technique, when the media file is copied the digital watermark gets copied as well. Digital watermarks are designed in such a way that they do not restrict the media file or change the media file in such a way it detracts the quality. Its main purpose is to detect misuse and act as a form of signature from the owner. <sup>[5]</sup>

	<br><br><br><br><br><br>		<br><br><br><br><br><br>
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	* Data Payload - The amount of information that can be carried in the watermark.		* Data Payload - The amount of information that can be carried in the watermark.
	* Transparency - The level of the opacity required to make the watermark visible or invisible.		* Transparency - The level of the opacity required to make the watermark visible or invisible.
-	* False Positive Rate - The rate in which the watermark will be falsely detected in ~~unwatermarked~~ files.	+	* False Positive Rate - The rate in which the watermark will be falsely detected in non-watermarked files.
	* Modification and Multiple Watermarks - The possibility of changing the watermark or embedding multiple watermarks.		* Modification and Multiple Watermarks - The possibility of changing the watermark or embedding multiple watermarks.
	* Cost - The cost required to embed the watermark into the digital file.<br><br>		* Cost - The cost required to embed the watermark into the digital file.<br><br>
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	==== Least Significant Bit Modification ====		==== Least Significant Bit Modification ====

-	Least Significant Bit (LSB) modification is the same process as that of Steganography and the watermark can be embedded multiple times if the watermark is small enough. Adding to the LSB algorithm, is to have a pseudo-random generator in which where the watermark is ~~palced~~ is random. Thus if the watermark undergoes an attack and one of the watermarks survive, than the process would be a success. The downside of LSB is that its not robust enough where any form of conversion would destroy the watermark. As well, if an outside party does discover the algorithm of the watermark, they would only need to change the last bit of each pixel to 1 and this would not ~~deteariate~~ the overall quality of the media file.	+	Least Significant Bit (LSB) modification is the same process as that of Steganography and the watermark can be embedded multiple times if the watermark is small enough. Adding to the LSB algorithm, is to have a pseudo-random generator in which where the watermark is placed is random. Thus if the watermark undergoes an attack and one of the watermarks survive, than the process would be a success. The downside of LSB is that its not robust enough where any form of conversion would destroy the watermark. As well, if an outside party does discover the algorithm of the watermark, they would only need to change the last bit of each pixel to 1 and this would not deteriorate the overall quality of the media file.


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	==== Wavelet Watermarking Techniques ====		==== Wavelet Watermarking Techniques ====

-	Wavelet Watermarking techniques uses the [http://en.wikipedia.org/wiki/Discrete_Wavelet_Transform Discrete Wavelet Transform] (DWT) to ~~seperate~~ the image into different resolutions. Once the image has been ~~seperated~~, the watermarked image can be ~~embbeded~~ into these regions. The reason to use such a technique is that higher quality watermarks can be added, which in turns increases the robustness of the watermark without impacting the image quality. The CDMA spread-spectrum can again be added to this technique in order to increase the security of the watermark. It has also been said this technique would be able to survive attacks such as conversion and image altering.<br><br>	+	Wavelet Watermarking techniques uses the [http://en.wikipedia.org/wiki/Discrete_Wavelet_Transform Discrete Wavelet Transform] (DWT) to separate the image into different resolutions. Once the image has been separated, the watermarked image can be embedded into these regions. The reason to use such a technique is that higher quality watermarks can be added, which in turns increases the robustness of the watermark without impacting the image quality. The CDMA spread-spectrum can again be added to this technique in order to increase the security of the watermark. It has also been said this technique would be able to survive attacks such as conversion and image altering.<br><br>
	== Countermeasures ==		== Countermeasures ==

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-	--[[User:Ganv\|Ganv]] 10:36, 11 April 2009 (EDT)	+	--[[User:Ganv\|Ganv]] 10:33, 12 April 2009 (EDT)

Ganv at 14:36, 11 April 2009

2009-04-11T14:36:18Z

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	Since the emergence of the Internet, digital distribution of media and documents has vastly increased and is constantly increasing every year. On this note, the distribution of copyright material has always been a concern for people trying to protect their work and this is where digital watermarking can become useful. Those who are worried of people eavesdropping on their conversations by email, important documents being read, or video chat being seen by others can use steganographic techniques to protect themselves. In order to know what applications these techniques can be used for, it is best to know the different ways of implementing the techniques. Steganography and digital watermarking can be broken down into four different subcategories in which the existence of the technique is either known or unknown to the public along with the original file.		Since the emergence of the Internet, digital distribution of media and documents has vastly increased and is constantly increasing every year. On this note, the distribution of copyright material has always been a concern for people trying to protect their work and this is where digital watermarking can become useful. Those who are worried of people eavesdropping on their conversations by email, important documents being read, or video chat being seen by others can use steganographic techniques to protect themselves. In order to know what applications these techniques can be used for, it is best to know the different ways of implementing the techniques. Steganography and digital watermarking can be broken down into four different subcategories in which the existence of the technique is either known or unknown to the public along with the original file.

-	<center>[[Image:sandwtable.png]]</center>	+	<center>[[Image:sandwtable.png\|Subcategories of Steganography and Watermarking]]</center>

	Covert watermarking is embedding a watermark related to the recipient of each copy of the file, but unaware that the watermark exists. Thus, if the file is leaked to third parties, the recipient who leaked the file can be traced. Covert steganography is embedding data unrelated to the original work. An overt watermark is when the presence of the watermark is known to others besides the creators, whether visually or told of the watermark. Overt steganography is similar to covert steganography in terms of the hidden information is unrelated to the signal in which it is embedded in. However with overt steganography, the information is only hidden to certain parties but visible to others, example timestamps. <sup>[7]</sup>		Covert watermarking is embedding a watermark related to the recipient of each copy of the file, but unaware that the watermark exists. Thus, if the file is leaked to third parties, the recipient who leaked the file can be traced. Covert steganography is embedding data unrelated to the original work. An overt watermark is when the presence of the watermark is known to others besides the creators, whether visually or told of the watermark. Overt steganography is similar to covert steganography in terms of the hidden information is unrelated to the signal in which it is embedded in. However with overt steganography, the information is only hidden to certain parties but visible to others, example timestamps. <sup>[7]</sup>
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	[http://en.wikipedia.org/wiki/Least_significant_bit Least Significant Bit] (LSB) insertion is having the rightmost bit of a binary number inserted with a different value. Which means that for every 8-bit binary number of an image, the LSB is replaced with 1-bit from the hidden message. The downside of this technique is that if the media file, say an image, is ever converted from one format to another (GIF to JPEG) the information in the message could be distorted.		[http://en.wikipedia.org/wiki/Least_significant_bit Least Significant Bit] (LSB) insertion is having the rightmost bit of a binary number inserted with a different value. Which means that for every 8-bit binary number of an image, the LSB is replaced with 1-bit from the hidden message. The downside of this technique is that if the media file, say an image, is ever converted from one format to another (GIF to JPEG) the information in the message could be distorted.

-	<center>[[Image:lsb.png]]</center>	+	<center>[[Image:lsb.png\|Example of LSB insertion in a 24-bit image]]</center>


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-	--[[User:Ganv\|Ganv]] 10:32, 11 April 2009 (EDT)	+	--[[User:Ganv\|Ganv]] 10:36, 11 April 2009 (EDT)

Ganv at 14:32, 11 April 2009

2009-04-11T14:32:15Z

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-	--[[User:Ganv\|Ganv]] 10:31, 11 April 2009 (EDT)	+	--[[User:Ganv\|Ganv]] 10:32, 11 April 2009 (EDT)

Ganv at 14:31, 11 April 2009

2009-04-11T14:31:38Z

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Ganv at 14:31, 11 April 2009

2009-04-11T14:31:12Z

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Ganv at 14:29, 11 April 2009

2009-04-11T14:29:33Z

← Older revision		Revision as of 14:29, 11 April 2009
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	== What is Steganography? ==		== What is Steganography? ==

-	[[Image:steg2.png\|right\|250px\|]]	+	[[Image:steg2.png\|right\|250px\|Theoretical: Secret information is hidden within the image file]]

	Steganography is the method of concealing a message, and its		Steganography is the method of concealing a message, and its
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	== What is Digital Watermarking? ==		== What is Digital Watermarking? ==
-	[[Image:cov2watermark.png\|right\|250px\|]]	+	[[Image:cov2watermark.png\|right\|250px\|File displaying both visible and invisible watermarks]]
	Digital watermarking is the process of embedding a symbol of some sort into the media file to distinguish the file from others. The embbeded watermark is meant to be permenant and follows a process in which there is alterations to the media file. Digital watermarking can be hidden or seen in plain sight by other parties. Deciding on whether to use visible/invisible watermarking depends on the function of the media file, but with either technique, when the media file is copied the digital watermark gets copied as well. Digital watermarks are designed in such a way that they do not restrict the media file or change the media file in such a way it detracts the quality. Its main purpose is to detect misuse and act as a form of signature from the owner. <sup>[5]</sup>		Digital watermarking is the process of embedding a symbol of some sort into the media file to distinguish the file from others. The embbeded watermark is meant to be permenant and follows a process in which there is alterations to the media file. Digital watermarking can be hidden or seen in plain sight by other parties. Deciding on whether to use visible/invisible watermarking depends on the function of the media file, but with either technique, when the media file is copied the digital watermark gets copied as well. Digital watermarks are designed in such a way that they do not restrict the media file or change the media file in such a way it detracts the quality. Its main purpose is to detect misuse and act as a form of signature from the owner. <sup>[5]</sup>

Ganv at 14:23, 11 April 2009

2009-04-11T14:23:42Z

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-	--[[User:Ganv\|Ganv]] 20:46, 10 April 2009 (EDT)	+	--[[User:Ganv\|Ganv]] 10:23, 11 April 2009 (EDT)

Ganv at 14:22, 11 April 2009

2009-04-11T14:22:46Z

Ganv at 00:46, 11 April 2009

2009-04-11T00:46:23Z

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Ganv at 00:45, 11 April 2009

2009-04-11T00:45:46Z

← Older revision		Revision as of 00:45, 11 April 2009
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	Steganography is the method of concealing a message, and its		Steganography is the method of concealing a message, and its
-	very existance is a secret and only known to the person(s) who placed it. Historical steganography involved dissapearing inks and masking letters to hide the information. While modern steganography, information hiding involves hiding data in digital media where by slightly altering the media causes a message to be embedded without anyone noticing any loss to the actual media file. Since steganography is a form of "security through obscurity", where it protects the messages and the known parties through secrecy, it is often combined with cryptography so that even if the message is found, it still cannot be read. <sup>[9]</sup>	+	very existance is a secret and only known to the person(s) who placed it. Historical steganography involved dissapearing inks and masking letters to hide the information. While modern steganography, information hiding involves hiding data in digital media where by slightly altering the media causes a message to be embedded without anyone noticing any loss to the actual media file. Since steganography is a form of "[http://en.wikipedia.org/wiki/Security_through_obscurity security through obscurity]", where it protects the messages and the known parties through secrecy, it is often combined with cryptography so that even if the message is found, it still cannot be read. <sup>[9]</sup>

	<br><br><br><br><br><br>		<br><br><br><br><br><br>

← Older revision		Revision as of 14:22, 11 April 2009
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	== What is Steganography? ==		== What is Steganography? ==

-	[[Image:steg2.png\|~~thumb~~\|~~581px~~\|]]	+	[[Image:steg2.png\|right\|250px\|]]

	Steganography is the method of concealing a message, and its		Steganography is the method of concealing a message, and its
	very existance is a secret and only known to the person(s) who placed it. Historical steganography involved dissapearing inks and masking letters to hide the information. While modern steganography, information hiding involves hiding data in digital media where by slightly altering the media causes a message to be embedded without anyone noticing any loss to the actual media file. Since steganography is a form of "[http://en.wikipedia.org/wiki/Security_through_obscurity security through obscurity]", where it protects the messages and the known parties through secrecy, it is often combined with cryptography so that even if the message is found, it still cannot be read. <sup>[9]</sup>		very existance is a secret and only known to the person(s) who placed it. Historical steganography involved dissapearing inks and masking letters to hide the information. While modern steganography, information hiding involves hiding data in digital media where by slightly altering the media causes a message to be embedded without anyone noticing any loss to the actual media file. Since steganography is a form of "[http://en.wikipedia.org/wiki/Security_through_obscurity security through obscurity]", where it protects the messages and the known parties through secrecy, it is often combined with cryptography so that even if the message is found, it still cannot be read. <sup>[9]</sup>

-	<br><br><br><br><br><br>	+	<br><br><br><br><br><br><br>

	== What is Digital Watermarking? ==		== What is Digital Watermarking? ==
-	[[Image:cov2watermark.png\|~~thumb~~\|~~420px~~\|]]	+	[[Image:cov2watermark.png\|right\|250px\|]]
	Digital watermarking is the process of embedding a symbol of some sort into the media file to distinguish the file from others. The embbeded watermark is meant to be permenant and follows a process in which there is alterations to the media file. Digital watermarking can be hidden or seen in plain sight by other parties. Deciding on whether to use visible/invisible watermarking depends on the function of the media file, but with either technique, when the media file is copied the digital watermark gets copied as well. Digital watermarks are designed in such a way that they do not restrict the media file or change the media file in such a way it detracts the quality. Its main purpose is to detect misuse and act as a form of signature from the owner. <sup>[5]</sup>		Digital watermarking is the process of embedding a symbol of some sort into the media file to distinguish the file from others. The embbeded watermark is meant to be permenant and follows a process in which there is alterations to the media file. Digital watermarking can be hidden or seen in plain sight by other parties. Deciding on whether to use visible/invisible watermarking depends on the function of the media file, but with either technique, when the media file is copied the digital watermark gets copied as well. Digital watermarks are designed in such a way that they do not restrict the media file or change the media file in such a way it detracts the quality. Its main purpose is to detect misuse and act as a form of signature from the owner. <sup>[5]</sup>

-	<br><br><br><br><br>	+	<br><br><br><br><br><br>


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	Some applications of steganography are <sup>[7]</sup>:		Some applications of steganography are <sup>[7]</sup>:

-	* Protection of Data Alteration - "[http://en.wikipedia.org/wiki/Digital_certificate Digital Certificates]" act as a way of protecting data by embedding the information.	+	* Protection of Data Alteration - "[http://en.wikipedia.org/wiki/Digital_certificate Digital Certificates]" as an example, act as a way of protecting data by embedding the information.
	* Confidential Communication - Where steganographic techniques could provide a way of communicating between two parties without others knowing.		* Confidential Communication - Where steganographic techniques could provide a way of communicating between two parties without others knowing.
	* Media Database Systems - Use of embedded messages in files to quickly identify them.		* Media Database Systems - Use of embedded messages in files to quickly identify them.
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	* Transaction Tracking - Track media files that were illegally distributed or to determine the route the file took.		* Transaction Tracking - Track media files that were illegally distributed or to determine the route the file took.
	* Content Authentication - The embedded watermarks can add as signatures where the information can be used to authenticate the originality of the file.		* Content Authentication - The embedded watermarks can add as signatures where the information can be used to authenticate the originality of the file.
-	* Copy Control - Watermarks can be used in recording equipment to determine what content may ~~or may not~~ be copied.	+	* Copy Control - Watermarks can be used in recording equipment to determine what content may be copied.
	* Device Control - Watermarks can be used to make devices react a certain way and display certain content.		* Device Control - Watermarks can be used to make devices react a certain way and display certain content.
	* [http://en.wikipedia.org/wiki/Legacy_system Legacy] Enhancement - Watermarks can be used to improve functionality of existing systems.		* [http://en.wikipedia.org/wiki/Legacy_system Legacy] Enhancement - Watermarks can be used to improve functionality of existing systems.
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	* Statistical Undetectability - The probability of detecting a steganographic technique based off assumptions.		* Statistical Undetectability - The probability of detecting a steganographic technique based off assumptions.
	* False Alarm Rate - The probability that an algorithm will detect and report the presence of a secret message when there is none.		* False Alarm Rate - The probability that an algorithm will detect and report the presence of a secret message when there is none.
-	* Stego Key - ~~Used with~~ a publicly known algorithm to embed a secret message into the media file.<br><br>	+	* Stego Key - Possibility of using a publicly known algorithm to embed a secret message into the media file.<br><br>
	=== Properties of Watermarked Systems ===		=== Properties of Watermarked Systems ===

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	* [http://en.wikipedia.org/wiki/Fidelity Fidelity] - The perceptive quality of a watermarked content.		* [http://en.wikipedia.org/wiki/Fidelity Fidelity] - The perceptive quality of a watermarked content.
	* Data Payload - The amount of information that can be carried in the watermark.		* Data Payload - The amount of information that can be carried in the watermark.
-	* ~~Cipher and Watermark Keys~~ - ~~Ciphers~~ to ~~control message encryption and~~ watermark ~~keys to control embedding and detection~~.	+	* Transparency - The level of the opacity required to make the watermark visible or invisible.
	* False Positive Rate - The rate in which the watermark will be falsely detected in unwatermarked files.		* False Positive Rate - The rate in which the watermark will be falsely detected in unwatermarked files.
	* Modification and Multiple Watermarks - The possibility of changing the watermark or embedding multiple watermarks.		* Modification and Multiple Watermarks - The possibility of changing the watermark or embedding multiple watermarks.