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US6557103B1 Expired / Lapsed US ⏱️ 0.0 years remaining

Spread spectrum image steganography

Assignee: United States Department of the Army
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Filing: 1999-02-11
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Granted: 2003-04-29
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Expires: 2019-02-11
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Abstract

Abstract The Spread Spectrum Image Steganography (SSIS) of the present invention is a data hiding/secret communication steganographic system which uses digital imagery as a cover signal. SSIS provides the ability to hide a significant quantity of information bits within digital images while avoiding detection by an observer. The message is recovered with low error probability due the use of error control coding. SSIS payload is, at a minimum, an order of magnitude greater than of existing watermarking methods. Furthermore, the original image is not needed to extract the hidden information. The proposed recipient need only possess a key in order to reveal the secret message. The very existence of the hidden information is virtually undetectable by human or computer analysis. Finally, SSIS provides resiliency to transmission noise, like that found in a wireless environment and low levels of compression.

Inventors

  • 👤 Charles G. Boncelet, Jr.
  • 👤 Lisa M. Marvel
  • 👤 Charles T. Retter

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 13:19
CPC Classifications
H; H04; H04K; H04K1/00; H04N; H04N1/00; H04N1/32; H04N1/32101; H04N1/32144; H04N1/32149; H04N2201/00; H04N2201/32; H04N2201/3201; H04N2201/3269; H04N2201/327; H04N2201/328; H04N2201/3281; H04N2201/3283

Claims Analysis

Total Claims: 20
Claim 1
Independent Claim 79 words
A method of decoding steganographic messages embedded within digital signals comprising the following steps: filtering the digital signal with a restoration filter to produce a restored digital signal; subtracting the restored digital signal from the digital signal to produce a difference signal; deinterleaving the difference signal; replicating a pseudorandom spreading sequence; demodulating the deinterleaved signal with the spreading sequence to construct an estimate of the message; decoding the message with an error correcting code to produce a decoded message.
Claim 2
Independent Claim 79 words
A method of decoding steganographic messages embedded within digital signals comprising the following steps: filtering the digital signal with a restoration filter to produce a restored digital signal; subtracting the restored digital signal from the digital signal to produce a difference signal; deinterleaving the difference signal; replicating a pseudorandom spreading sequence; demodulating the deinterleaved signal with the spreading sequence to construct an estimate of the message; decoding the message with an error correcting code to produce a decoded message.
Claim 3
Dependent Claim 15 words
The method of claim 1 , further comprising: decrypting the decoded message with a key.
Claim 4
Independent Claim 95 words
A method of decoding steganographic messages embedded within digital images comprising the following steps: filtering the digital image with a restoration filter to produce a restored digital image; subtracting the restored digital image from the digital image to produce a difference signal; deinterleaving the difference signal according to a key; replicating a pseudorandom spreading sequence according to a key; demodulating the deinterleaved signal with the spreading sequence to construct an estimate of the message; decoding the message with an error correcting code comprising a binary expansion of a Reed-Solomon code to produce a decoded message.
Claim 5
Independent Claim 95 words
A method of decoding steganographic messages embedded within digital images comprising the following steps: filtering the digital image with a restoration filter to produce a restored digital image; subtracting the restored digital image from the digital image to produce a difference signal; deinterleaving the difference signal according to a key; replicating a pseudorandom spreading sequence according to a key; demodulating the deinterleaved signal with the spreading sequence to construct an estimate of the message; decoding the message with an error correcting code comprising a binary expansion of a Reed-Solomon code to produce a decoded message.
Claim 6
Independent Claim 79 words
A method of steganography for concealing messages within digital signals comprising the steps of: encoding an input message with an error correcting code to produce an encoded message; generating a spreading sequence with a pseudorandom noise generator according to a key; modulating the encoded message by the spreading sequence using a piecewise linear technique to produce an embedded signal; and combining the embedded signal with a cover signal to produce a stegosignal in which the input message is embedded.
Claim 7
Independent Claim 79 words
A method of steganography for concealing messages within digital signals comprising the steps of: encoding an input message with an error correcting code to produce an encoded message; generating a spreading sequence with a pseudorandom noise generator according to a key; modulating the encoded message by the spreading sequence using a piecewise linear technique to produce an embedded signal; and combining the embedded signal with a cover signal to produce a stegosignal in which the input message is embedded.
Claim 8
Dependent Claim 15 words
The method of claim 4 , further comprising encrypting the input message with a key.
Claim 9
Dependent Claim 19 words
The method of claim 4 , further comprising interleaving the embedded signal to enhance recovery of the embedded signal.
Claim 10
Dependent Claim 20 words
The method of claim 6 , where the step of interleaving the embedded signal is performed according to a key.
Claim 11
Dependent Claim 14 words
The method of claim 4 , where the cover signal is a digital image.
Claim 12
Dependent Claim 19 words
The method of claim 4 , where the error correcting code comprises a binary expansion of a Reed-Solomon code.
Claim 13
Dependent Claim 15 words
The method of claim 4 , wherein the piecewise linear function comprises a sign function.
Claim 14
Dependent Claim 77 words
The method of claim 4 , wherein the generation of the spreading sequence and piecewise linear modulation comprises: generating a uniformly distributed random sequence, u; generating a second sequence u′ according to the following formula u ′ = { u + 0.5 , 0 ≤ u ≤ 0.5 u - 0.5 , 0 ≤ u ≤ 0.5 ; forming a spreading sequence by a switch arbitrator which selects from u and u′ arbitrated by the input message.
Claim 15
Independent Claim 119 words
A method of steganography for concealing messages within digital signals comprising the following steps: encrypting an input message with a key and encoding the input message with an error correcting code to produce an encoded message; generating a spreading sequence with a pseudorandom noise generator according to a key; modulating the encodeded message by the spreading sequence to produce an embedded signal and interleaving the embedded signal to enhance recovery of the embedded signal, where the interleaving step is performed according to a key; combining the embedded signal with a cover signal to produce a stegosignal in which the input message is embedded; and quantizing the stegosignal to preserve the original the original dynamic range of the cover signal.
Claim 16
Independent Claim 119 words
A method of steganography for concealing messages within digital signals comprising the following steps: encrypting an input message with a key and encoding the input message with an error correcting code to produce an encoded message; generating a spreading sequence with a pseudorandom noise generator according to a key; modulating the encodeded message by the spreading sequence to produce an embedded signal and interleaving the embedded signal to enhance recovery of the embedded signal, where the interleaving step is performed according to a key; combining the embedded signal with a cover signal to produce a stegosignal in which the input message is embedded; and quantizing the stegosignal to preserve the original the original dynamic range of the cover signal.
Claim 17
Independent Claim 123 words
A method of steganography for concealing messages within digital images comprising the following steps: encrypting an input message with a key; encoding the input message with an error correcting code comprising a binary expansion of a Reed-Solomon code to produce an encoded message; generating a spreading sequence with a pseudorandom noise generator according to a key; modulating the encoded message by the spreading sequence using a piecewise linear technique to produce an embedded signal; interleaving the spread spectrum modulated signal according to a key; combining the embedded signal with a cover image to produce spread spectrum modulated stegoimage in which the input message is embedded; and quantizing the interleaved spread spectrum modulated stegoimage to preserve the original dynamic range of the cover image.
Claim 18
Independent Claim 123 words
A method of steganography for concealing messages within digital images comprising the following steps: encrypting an input message with a key; encoding the input message with an error correcting code comprising a binary expansion of a Reed-Solomon code to produce an encoded message; generating a spreading sequence with a pseudorandom noise generator according to a key; modulating the encoded message by the spreading sequence using a piecewise linear technique to produce an embedded signal; interleaving the spread spectrum modulated signal according to a key; combining the embedded signal with a cover image to produce spread spectrum modulated stegoimage in which the input message is embedded; and quantizing the interleaved spread spectrum modulated stegoimage to preserve the original dynamic range of the cover image.
Claim 19
Dependent Claim 14 words
The method of claim 13 wherein the piecewise linear function comprises a sign function.
Claim 20
Dependent Claim 70 words
The method of claim 13 wherein generation of the spreading sequence comprises generating a uniformly distributed random sequence, u; generating a second sequence u′ according to the following formula u ′ = { u + 0.5 , 0 ≤ u ≤ 0.5 u - 0.5 , 0 ≤ u ≤ 0.5 forming a spreading sequence by a switch arbitrator which selects from u and u′ arbitrated by the input message.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2006-04-28 2006-10-28 2007-04-29 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2010-04-28 2010-10-28 2011-04-29 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2014-04-28 2014-10-28 2015-04-29 $7700.00 Window Closed / Lapsed

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