DIGITAL SIGNATURE AND WATERMARKING

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					DIGITAL SIGNATURE AND
WATERMARKING




         TheDirectData.com   1
    In today's commercial environment, establishing a
    framework for the authentication of computer-based
    information requires a familiarity with concepts and
    professional skills from both the legal and computer security
    fields.
   Thus digital signatures are used. Signatures are nothing but
    mark of authenticating any document.




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Why do we need verification?
   A leading Japanese company has found a way to get your
    DNA into a pen. You sign a document and it is digitally
    scanned.
   Identity should be verified when ever there is doubt of the
    3rd party being whom they say they are or when there is
    personal information at risk.
   Personal information like credit card details and banking
    information should be kept safe using digital certification as
    one of the security layers.



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DIGITAL SIGNATURE:

   Digital signatures are a way to ensure the integrity of a
    message or other data using public key cryptography.
   Digital signatures help organizations sustain signer
    authenticity, accountability, data integrity and non-
    repudiation of documents and transactions.




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Components of digital signature:

   Public key:
   Name and e-mail address:
   Expiration date of the public key :
   Name of the company :
   Serial number of the Digital ID:
   Digital signature of the CA (certification Authority):




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Signatures and Laws:

   Evidence:.
   Ceremony:
   Approval:
   Efficiency and logistics :




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DIGITAL SIGNATURE WORKS ON THE
FOLLOWING PROCESS
    A Singing algorithm
    A key generation algorithm
    A verification algorithm
 . When a message with a digital signature is transmitted and
     received, the following parties are involved:
1) The signer who signs the document;
2) The verifier who receives the signed document and verifies the
     signature
3) The arbitrator who arbitrates any disputes between the signer
     and the verifier if there is a disagreement on the validity of
     the digital signature.
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DIGITAL SIGNATURE STANDARD

   This Standard specifies a Digital Signature Algorithm (DSA)
    appropriate for applications requiring a digital rather than
    written signature. The DSA digital signature is a pair of
    large numbers represented in a computer as strings of binary
    digits.
   The DSA provides the capability to generate and verify
    signatures.




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   A hash function is used in the signature generation process to
    obtain a condensed version of data, called a message digest .
   The message digest is then input to the DSA to generate the
    digital signature. The digital signature is sent to the intended
    verifier along with the signed data (often called the message).
    The verifier of the message and signature verifies the
    signature by using the sender's public key.
    The same hash function must also be used in the verification
    process. The hash function is specified in a separate standard,
    the Secure Hash Standard (SHS), FIPS 180.


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Digital Certificate

   A digital certificate contains:
   The user's distinguished name (a unique identifier)
   The issuing Certification Authority's distinguished name
   The user's public key
   The validity period
   The certificate's serial number
   The issuing Certification Authority's digital signature,
    verifying the information in the digital certificate.


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PROBLEMS IN DIGITAL SIGNATURE:

   Imposters, by minimizing the risk of dealing with imposters
    or persons who attempt to escape responsibility by claiming
    to have been impersonated;
   Message integrity, by minimizing the risk of undetected
    message tampering and forgery, and of false claims that a
    message was altered after it was sent;
   Formal legal requirements, by strengthening the view that
    legal requirements of form, such as writing, signature, and an
    original document, are satisfied, since digital signatures are
    functionally on a par with, or superior to paper forms.
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DIGITAL WATERMARKING:

   Digital watermarking is a technique which allows an
    individual to add hidden copyright notices or other
    verification messages to digital audio, video, or image signals
    and documents. Such hidden message is a group of bits
    describing information pertaining to the signal or to the
    author of the signal (name, place, etc.).




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TYPES OF WATERMARKING:

   VIDEO WATERMARKING: The watermark image is
    inserted into the video media.
   AUDIO WATERMARKING: The audio media is used to
    insert the information.
   TEXT WATERMARKING: The text media is used to insert
    the information .




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Types of watermark.

   Visible watermark
   Invisible watermark
   Public watermark
   Private watermark
   Fragile watermark
   Perceptual watermark




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How to create watermarking image

   Digital Watermarking software looks for noise in digital
    media and replaces it with useful information. A digital
    media file is nothing more than a large list of 0’s and 1’s.
   The watermarking software determines which of these 0’s
    and 1’s correspond to redundant or irrelevant details.
    For example, the software might identify details in an image
    that are too fine for the human eye to see and flag the
    corresponding 0’s and 1’s as irrelevant noise. Later the
    flagged 0’s and 1’s can be replaced by a digital watermark.


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LIMITATIONS OF WATERMARKING:



-> There will likely be non-commercial applications,
  or those with limited vulnerability to theft,
  where "good enough watermarking" will suffice.
     all watermarking techniques will be useful in resolvingo
-> Not
  ownership disputes in the court


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FUTURE OF WATERMARKING:

   The challenge is to develop ever more invisible,
    decodable, and permanent watermarking methods,
    and perhaps to meet even more specifications as they
    are demanded.




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CONCLUSION:

   Digital watermarking can successfully be employed if
    the value of the digital media warrants the added
    expense. If not, it is an exercise in futility.
   Digital signatures have gained popularity in past
    years and now it is used in many organization,
    banks,etc




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   THANK YOU:



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posted:9/2/2011
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