Steganographic method and device

• US 20050177727A1
• Filed: 02/07/2005
• Published: 08/11/2005
• Est. Priority Date: 06/07/1995
• Status: Active Grant

• Current Assignee: Wistaria Trading Inc.
• Original Assignee: Wistaria Trading Inc.
• Inventors: Cooperman, Marc, Moskowitz, Scott A.
• Granted Patent: US 7,761,712 B2
• Time in Patent Office: Days
• US Class Current: 713/176
• CPC Class Codes: G06T 1/0021 Image watermarking
• CPC Class Codes: G06T 2201/0064 for copy protection or copy management, e.g. CGMS, copy only once, one-time copy
• CPC Class Codes: G10L 19/018 Audio watermarking, i.e. embedding inaudible data in the audio signal
• CPC Class Codes: G11B 20/00891 embedded in audio data
• CPC Class Codes: H04L 2209/04 Masking or blinding
• CPC Class Codes: H04L 2209/08 Randomization, e.g. dummy operations or using noise
• CPC Class Codes: H04L 2209/605 Copy protection
• CPC Class Codes: H04L 2209/608 Watermarking
• CPC Class Codes: H04L 9/0643 Hash functions, e.g. MD5, SHA, HMAC or f9 MAC
• CPC Class Codes: H04L 9/0656 Pseudorandom key sequence combined element-for-element with data sequence, e.g. one-time-pad [OTP] or Vernam's cipher
• CPC Class Codes: H04L 9/12 Transmitting and receiving encryption devices synchronised or initially set up in a particular manner
• CPC Class Codes: H04L 9/3247 involving digital signatures
• CPC Class Codes: H04L 9/3263 involving certificates, e.g. public key certificate [PKC] or attribute certificate [AC]; Public key infrastructure [PKI] arrangements network architectures or network communication protocols for supporting authentication of entities using certificates in a packet data network H04L63/0823
• CPC Class Codes: H04N 1/32149 Methods relating to embedding, encoding, decoding, detection or retrieval operations
• CPC Class Codes: H04N 1/3216 using Fourier transforms
• CPC Class Codes: H04N 1/32187 with selective or adaptive application of the additional information, e.g. in selected frequency coefficients
• CPC Class Codes: H04N 1/32245 Random or pseudorandom selection of pixels
• CPC Class Codes: H04N 21/23614 Multiplexing of additional data and video streams arrangements for simultaneous broadcast of plural pieces of information H04H20/28
• 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 21/2541 Rights Management protecting software against unauthorised usage in a vending or licensing environment G06F21/10; security in data switching network management H04L41/28; security management or policies for network security H04L63/20; access security in wireless networks H04W12/08
• CPC Class Codes: H04N 21/4348 : Demultiplexing of additional data and video streams
• CPC Class Codes: H04N 21/835 : Generation of protective data, e.g. certificates protecting software against unauthorised usage in a vending or licensing environment G06F21/10
• CPC Class Codes: H04N 21/8352 : involving content or source identification data, e.g. Unique Material Identifier [UMID]
• 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 2201/3205 : of identification information, e.g. name or ID code H04N2201/3209 takes precedence
• 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 2201/327 : which are undetectable to the naked eye, e.g. embedded codes
• CPC Class Codes: H04N 2201/3281 : Encryption; Ciphering
• CPC Class Codes: H04N 7/1675 : Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58

Abstract

An apparatus and method for encoding and decoding additional information into a stream of digitized samples in an integral manner. The information is encoded using special keys. The information is contained in the samples, not prepended or appended to the sample stream. The method makes it extremely difficult to find the information in the samples if the proper keys are not possesed by the decoder. The method does not cause a significant degradation to the sample stream. The method is used to establish ownership of copyrighted digital multimedia content and provide a disincentive to piracy of such material.

Claims

1. A method, called stega-cipher, comprising the step of using random keys in combination with steganographic technique to encode additional information into digitized samples in a manner that does not significantly degrade the signal generated from the sample stream and makes it impossible to extract the information without the keys.

2-24. -24. (canceled)

25. A method for decoding independent information encoded into digital data comprising:

providing a key, said key providing an indication of where, in the digital data, the independent information can be located;

using said key to locate a first portion of said independent information in said digital data; and

using said key to determine said independent information from said digital data.

26. The method according to claim 25 wherein:

said key includes decoding information for locating said independent information within at least one selected from the group consisting of;

(1) the time domain of the digital data (2) the frequency domain of the digital data and (3) the bit-depth of the digital data.

27. The method according to claim 25 wherein:

said key includes at least one mask, said mask indicating where in the digital data, the independent information can be located.

28. The method according to claim 27 wherein:

said mask indicates, within a sample window of the digital data, where the independent information can be located.

29. The method according to claim 25 wherein:

the digital data includes a start delimiter indicating a portion of the digital data where the independent information is encoded and using said key to locate a first portion of said independent information in said digital data includes locating said start delimiter in the digital data.

30. The method according to claim 25 wherein:

the independent information is encoded in the digital data in at least two locations of the digital data; and

further comprising using said key to determine said independent information from at least two locations of the digital data.

31. The method according to claim 25 wherein:

the independent information is encoded in the digital data in a plurality of randomly or pseudo-randomly assigned locations of the digital data; and

further comprising using said key to determine said independent information from at least two locations of the digital data.

32. The method according to claim 25 wherein:

the independent information includes a encode hash of at least a portion of the digital data and further comprising generating a decode hash of at least a portion of the digital data and comparing said encode hash to said decode hash.

33. The method according to claim 25 wherein:

the independent information includes a encode hash of at least a portion of the digital data that contains the independent information, wherein the encode hash is insensitive to encoding the independent information into the digital data and further comprising generating a decode hash of at least a portion of the digital data that contains the independent information and comparing said encode hash to said decode hash.

34. The method according to claim 25 wherein:

the independent information includes information for enabling use of the digital data and further comprising enabling the use of the digital data as a function of the independent information.

35. A method for protecting a digital signal comprising the steps of:

a) providing a carrier signal;

b) using a steganographic key to encode independent information including a digital watermark into the carrier signal.

36. The method according to claim 35, wherein the digital watermark, includes at least one selected from the group consisting of:

rights ownership identification, authorship identification of the encoded carrier signal, ownership identification of a unique copy of the encoded carrier signal, information for enabling use of the encoded carrier signal, and a serialization code uniquely identifying a copy of the encoded carrier signal.

43. The method according to claim 35, further comprising the step of:

c) using a map table to define where watermark information is to be encoded based on random or pseudo-random masks into the carrier signal, wherein the map table is defined such that any index of the map table enables encoding of information.

47. The method according to claim 35, further comprising the step of:

c) adding unique data to each individual watermark, rendering it distinct from any other watermark in the same sample stream.

48. The method according to claim 47, further comprising the step of:

d) computing a secure one way hash function of the carrier signal data in said sample windows, wherein said hash function is insensitive to changes introduced into the carrier signal for the purpose of carrying digital watermark information.

49. The method according to claim 48, further comprising the step of:

e) concatenating the hash value with the independent information, creating an expanded, unique digital watermark.

53. The method of claim 35, wherein the step of steganographically encoding independent information into the carrier signal causes an imperceptible change in the carrier signal.

37. A method for protecting a digital signal comprising:

a) providing a carrier signal that has been encoded with independent information; and

b) using a steganographic key to decode independent information including a digital watermark from the carrier signal.

38. The method according to claim 37, wherein the digital watermark includes at least one selected from the group consisting of:

rights ownership identification, authorship identification of the encoded carrier signal, ownership identification of a unique copy of the encoded carrier signal, information for enabling use of the encoded carrier signal, and a serialization code uniquely identifying a copy of the encoded carrier signal.

39. The method according to claim 37, further comprising the step of:

c) generating a first derivative encoded signal representing the original carrier signal combined with the encoded independent information, including the digital watermark, wherein the first derivative encoded signal is an arbitrarily close approximation of the original carrier signal.

40. The method according to claim 37, further comprising the step of:

c) decoding a single message bit from a single sample by reading a sample bit of the single sample as the message bit.

41. The method according to claim 37, further comprising the step of:

c) decoding a signal message bit from a single sample by mapping the single sample in the range of sample values which indicate a particular message bit value.

42. The method according to claim 37, further comprising the step of:

c) decoding a single message bit from a signal spectral value by mapping the single spectral into a range of sample values which indicate a particular message bit value.

44. The method according to claim 37, further comprising the step of:

c) selecting a mask set, said mask stet including one or more random or pseudo-random series of bits, referred to as masks;

d) selecting a random or pseudo-random start of message delimiter; and

e) selecting an input sample stream to be decoded.

45. The method according to claim 44, further comprising the step of:

f) computing a spectral transform of the sample stream prior to digital watermark data decoding.

46. The method according to claim 37, wherein the independent information contains, at least one selected from the group consisting of:

a hash value computed on the start of message delimiter, and a digital signature of the start of message delimiter.

50. The method according to claim 37, further comprising the step of:

c) obtaining a unique hash value contained in the independent information comprising part of the digital watermark.

51. The method according to claim 50, further comprising the step of:

d) computing a secure one way hash function of the carrier signal data in said sample windows, wherein said hash function is insensitive to changes introduced into the carrier signal for the purpose of carrying digital watermark information.

52. The method according to claim 51, further comprising the step of:

e) comparing the computed hash value to the value contained in the watermark.

54. The method of claim 37, wherein the step of steganographically decoding independent information into the carrier signal causes an imperceptible change in the carrier signal.