AU2013326454B2 - Embedding a digital watermark in a signal - Google Patents
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- AU2013326454B2 AU2013326454B2 AU2013326454A AU2013326454A AU2013326454B2 AU 2013326454 B2 AU2013326454 B2 AU 2013326454B2 AU 2013326454 A AU2013326454 A AU 2013326454A AU 2013326454 A AU2013326454 A AU 2013326454A AU 2013326454 B2 AU2013326454 B2 AU 2013326454B2
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
- H04L9/32—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols including means for verifying the identity or authority of a user of the system or for message authentication, e.g. authorization, entity authentication, data integrity or data verification, non-repudiation, key authentication or verification of credentials
- H04L9/3226—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols including means for verifying the identity or authority of a user of the system or for message authentication, e.g. authorization, entity authentication, data integrity or data verification, non-repudiation, key authentication or verification of credentials using a predetermined code, e.g. password, passphrase or PIN
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L2209/00—Additional information or applications relating to cryptographic mechanisms or cryptographic arrangements for secret or secure communication H04L9/00
- H04L2209/60—Digital content management, e.g. content distribution
- H04L2209/608—Watermarking
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Abstract
The invention concerns a transmission of a digital signal, in which - when it is transmitted, a vector corresponding to a digital signal to be transmitted, having the form of a sequence of N symbols, is projected onto a vector space, said vector space being orthogonal to at least one non-zero vector corresponding to a sequence of symbols defining a digital watermark, and - when it is received, the digital signal is authenticated by checking the orthogonality of a vector, corresponding to said received digital signal and having the form of a sequence of symbols, relative to said at least one vector defining a digital watermark.
Description
EMBEDDING A DIGITAL WATERMARK IN A SIGNAL
Field of the Invention
The present invention relates to a method for emission of a digital signal; a method for reception of a digital signal; an electronic emission system comprising a processor, a memory and an emission chain; and an electronic reception system, comprising a processor, a memory and an acquisition chain. For example, the field of the signal transmission, in terms of fixed or mobile radio communication systems. More precisely, the present invention deals with authentication of the signal.
In these systems, messages exchanged between two stations belonging to the same network are generally encrypted to ensure confidentiality of their content. But some particularly sensitive networks can be the object of malevolent attacks aiming to determine the encryption key used to encrypt transmitted messages and/or have the hacker passed off as a member of the network to infiltrate the latter or, at least, to significantly disrupt operation of the communications system as such.
It therefore seems necessary to add an extra layer of protection to ensure the authenticity and/or paternity of messages transmitted. A technique employed here consists of dissimulating a sign in a signal or a message, whereof the presence authenticates the signal or message. There are many processes for dissimulating a sign in a signal and they operate in temporal and/or frequential ranges. They typically consist of adding a signal having a pseudo-random character to the modulated signal. These are processes which could be qualified as “positive”, since in one way or another a pattern is effectively present in the signal, even though it is dissimulated.
For example, patent application US 2003/086585 classically describes the introduction of watermarks to media, for example an audio or video file or a photograph, by addition of watermarks to the data of the file.
However, such processes are not entirely satisfactory. In fact, the presence of the sign can be detected in the signal transmitted since it is present there, so to speak “positively”. The hacker of the communications network can try to reveal and counterfeit this sign.
It is generally desirable to overcome or ameliorate one or more of the above described difficulties, or to at least provide a useful alternative.
Summary of the Invention
According to the present invention, there is provided a method for emission of a digital signal, in which an electronic emission system performs the steps according to which: - a vector s corresponding to a digital signal to be transmitted taking the form of a sequence of N symbols is projected onto a vectorial space, said vectorial space being orthogonal to at least one non-zero vector q corresponding to a sequence of symbols defining a digital watermark, - the digital signal resulting from the projection is sent to an electronic reception system able to authenticate a received digital signal by verifying the orthogonality of a vector rRX, corresponding to said received digital signal and taking the form of a sequence of symbols, relative to at the least one non-zero vector q corresponding to the sequence of symbols defining the digital watermark.
According to the present invention, there is also provided a method for reception of a digital signal, wherein an electronic reception system: - receives a digital signal sent by an electronic emission system, said digital signal resulting from the projection of a vector s corresponding to a digital signal to be transmitted taking the form of a sequence of N symbols onto a vectorial space, said vectorial space being orthogonal to at least one non-zero vector q corresponding to a sequence of symbols defining a digital watermark, and - authenticates the received digital signal by verifying the orthogonality of a vector fRX, corresponding to said received digital signal and taking the form of a sequence of symbols, relative to at least one non-zero vector q corresponding to the sequence of symbols defining the digital watermark.
According to the present invention, there is also provided an electronic emission system comprising a processor, a memory and an emission chain, characterized in that the electronic emission system is configured to: - project a vector s corresponding to a digital signal to be transmitted taking the form of a sequence of N symbols onto a vectorial space, said vectorial space being orthogonal to at least one non-zero vector q corresponding to a sequence of symbols defining a digital watermark, - send the digital signal resulting from the projection in the form of a transmitted digital signal to an electronic reception system able to authenticate a received digital signal by verifying the orthogonality of a vector rRX, corresponding to said received digital signal and taking the form of a sequence of symbols, relative to at the least one non-zero vector q corresponding to the sequence of symbols defining the digital watermark.
According to the present invention, there is also provided an electronic reception system, comprising a processor, a memory and an acquisition chain, characterized in that the electronic reception system is configured to: - receive a digital signal sent by an electronic emission system, said digital signal resulting from the projection of a vector s corresponding to a digital signal to be transmitted taking the form of a sequence of N symbols onto a vectorial space, said vectorial space being orthogonal to at least one non-zero vector q corresponding to a sequence of symbols defining a digital watermark, and - verify the orthogonality of a vector fRX corresponding to said received digital signal with at least one non-zero vector q corresponding to the sequence of symbols defining the digital watermark.
The invention preferably aims to authenticate a signal during transmission, by means of a method offering heightened security relative to methods of the prior art, simplicity of use not needing powerful calculation, and limited alteration of the signal.
The invention preferably relates to a transmission method of a digital signal, in which - during sending, a vector corresponding to a digital signal to be transmitted taking the form of a sequence of N symbols is projected onto a vectorial space, said vectorial space being orthogonal to at least one non-zero vector corresponding to symbols defining a digital watermark, and - during reception, the digital signal is authenticated by verifying the orthogonality of a vector, corresponding to said received digital signal and taking the form of a sequence of symbols, relative to said at least one vector defining the digital watermark.
The invention preferably proposes for this purpose and according to a first preferred embodiment a sending method of a digital signal, in which an electronic emission system conducts the steps according to which: - a vector s corresponding to a digital signal to be transmitted taking the form of a sequence of N symbols is projected onto a vectorial space, said vectorial space being orthogonal to at least one non-zero vector q corresponding to a sequence of symbols defining a digital watermark, - the digital signal resulting from the projection is sent.
The invention according to the first preferred embodiment is advantageously completed by the various following characteristics taken singly or according to their different possible combinations: - the method further comprises a step according to which, prior to its transmission, the digital signal resulting from the projection is normalised such that the hermitian scalar product of the vector s corresponding to the signal to be transmitted with the vector rrx corresponding to the digital signal transmitted is equal to N; - the sequence of symbols defining said at least one digital watermark results from transformation of symbols of the digital signal to be transmitted, - the vector s corresponding to a digital signal to be transmitted taking the form of a sequence of N symbols is projected onto a vectorial space, said vectorial space being orthogonal to a non-zero plurality of K vectors each corresponding to a sequence of symbols defining a digital watermark; - the signal resulting from the projection is determined as being the first column of the generalised inverse, called Penrose pseudo-inverse, of the matrix M having the following dimensions (Κ+1)χΝ:
with T the time interval separating two consecutive symbols.
According to a second preferred embodiment, the invention proposes a reception method of a digital signal, in which an electronic reception system authenticates a received digital signal by verifying the orthogonality of a vector rRX, corresponding to said received digital signal and taking the form of a sequence of symbols, relative to at least one non-zero vector q corresponding to a sequence of symbols defining a digital watermark.
The invention according to the second preferred embodiment is advantageously completed by the various following characteristics taken singly or according to their different possible combinations: - to verify the orthogonality, the electronic reception system: - calculates a norm of the hermitian scalar product between said at least one vector q defining a digital watermark and the vector rRX corresponding to said received digital signal, - compares said norm to a determination threshold,
- determines that the vector fRX corresponding to said received digital signal is orthogonal to said at least one vector q defining a digital watermark when said norm is less than the determination threshold, and - determines that the vector fRX corresponding to said received digital signal is not orthogonal to said at least one vector q defining a digital watermark when said norm is greater than the determination threshold; - the electronic reception system authenticates a received digital signal by verifying the orthogonality of a vector rRX, corresponding to said received digital signal and taking the form of a sequence of symbols, relative to a plurality K of non-zero vectors each corresponding to a sequence of symbols defining a digital watermark; - the method comprises an estimation step of the signal-to-noise ratio of the received digital signal by the electronic reception system, said determination threshold being fixed as a function of said estimation; - the sequence of symbols defining said at least one digital watermark results from transformation of symbols of the received digital signal.
The invention according to a third preferred embodiment proposes an electronic emission system comprising a processor, a memory and an emission chain, said electronic emission system being configured to - project a vector s corresponding to a digital signal to be transmitted taking the form of a sequence of N symbols onto a vectorial space, said vectorial space being orthogonal to at least one non-zero vector q corresponding to a sequence of symbols defining a digital watermark, - send the digital signal resulting from the projection.
The invention according to a fourth preferred embodiment proposes an electronic reception system, comprising a processor, a memory and an acquisition chain, characterised in that the electronic reception system is configured to verify the orthogonality of a vector rRX corresponding to said received digital signal with a nonzero vector q corresponding to a sequence of symbols defining a digital watermark.
Preferably, to verify orthogonality, the electronic reception system is configured to: - calculate a norm of the hermitian scalar product between said at least one vector q defining a digital watermark and the vector rRX corresponding to said received digital signal, - compare said norm to a determination threshold, - determine that the vector rRX corresponding to said received digital signal is orthogonal to said at least one vector q defining a digital watermark when said norm is less than the determination threshold, and - determine that the vector rRX corresponding to said received digital signal is not orthogonal to said at least one vector q defining a digital watermark when said norm is greater than the determination threshold.
The invention also preferably relates to a computer program product comprising program code instructions for execution of the steps of the method according to the first or the second aspect of the invention, when said program is run by a processor. Preferably, said computer program product is a storage medium, for example a computer-readable memory.
The invention preferably dissimulates a digital watermark in a digital signal negatively, or hollow, that is, the authenticity of the message transmitted is verified by means of the imprint of the digital watermark in the digital signal, rather than of the digital watermark itself. The verification operation of the authenticity is easy and not complex, as it is done for example by means of a simple scalar product. Several watermarks can be superposed in the same modulated signal without mutual interference. Also, the distortion undergone by the modulated signal during superposition of the watermark is relatively low, even though it grows with the number of superposed watermarks.
Brief Description of the Figures
Preferred embodiments of the present invention are hereafter described, by way of non-limiting example only, with reference to the accompanying drawings, in which:
Figure 1 is a diagram showing a communications system between an electronic emission system and an electronic reception system;
Figure 2 is a diagram illustrating steps for executing the method according to a preferred embodiment of the invention; and
Figure 3 is a diagram illustrating steps for executing the method according to another preferred embodiment of the invention.
Detailed Description of Preferred Embodiments of the Invention
The scope of the invention is that of transmissions of a digital signal executed by means of a communications system between an electronic emission system and an electronic reception system. Figure 1 illustrates an example of a communications system according to a possible embodiment of the invention.
The electronic emission system 1 comprises a processor 12, a memory 14 and an emission chain 16 of a signal. For example, the electronic emission system 1 is a radio transmitter, the processor 12 is a DSP (Digital Signal Processor), and the emission chain 16 of a signal comprises an amplifier and an antenna.
The electronic reception system 2 comprises a processor 22, a memory 24 and a reception chain 26 of a signal. For example, the electronic reception system 2 is radio a receiver, the processor 22 is a DSP, and the reception chain 26 of a signal comprises an amplifier and an antenna.
Digital signals are represented by a suite of complex symbols, and the processing of a digital signal is illustrated by application of a matrix to a vector comprising complex variables representing the symbols of the digital signal, said complex variables being ordered according to the temporal ordering of the complex symbols of the digital signal. In this way a vector is linked to a digital signal.
Hereinbelow is a description by way of non-limiting example of a radio communications system based on the access technique TDMA (Time Division Multiple Access), such as for example DECT systems (Digital Enhanced Cordless Telecommunications) and PHS (Personal Handy-phone System) which are standards of cordless digital telephony mainly intended for individuals and enterprises. The invention can even be executed within the scope of other access techniques such as for example CDMA mode (Code Division Multiple Access) or the OFDM mode (Orthogonal Frequency-Division Multiplexing).
In a TDMA system, the messages digital exchanged are encapsulated in packets of data modulated by means of a given modulation diagram, such as for example QPSK modulation (acronym of Quadrature Phase Shift Keying) belonging to the linear group of modulations. These packets generally include other fields than the one containing the data to be transmitted, such as for example the synchronisation field which lets the receiver acquire and keep the temporal and frequential synchronisation with the sender.
During modulation, the binary sequence associated with a given packet is converted into a series of symbols (the size of which varies typically between 1 and 6 bits in the case of a linear modulation diagram of QAM type, acronym of Quadrature Amplitude Modulation), in turn associated with a particular amplitude and phase. The sequence of complex numbers obtained s(nT) with n = 1...N is a digital signal constituting the signal to be transmitted.
The electronic emission system 1 has at least one digital watermark, for example in the form of a local copy in its memory. A digital watermark is a digital signal, that is, a sequence of complex numbers consecutively separated by a constant time interval, constituting an identification code. The watermark is preferably imperceptible and undetectable by any system not knowing its use.
The electronic emission system 1 can also have a digital watermark in a form derived from the latter. For example, it can have the projection matrix orthogonal to a nonzero vector corresponding to a sequence of symbols defining a digital watermark. A digital watermark can still be obtained from transformation of the signal to be transmitted, for example by permutation of symbols.
In the prior art, it is when present in a signal that the digital watermark guarantees the authenticity and/or the paternity of the message contained in the signal, for example a text or audio file, an image or a video. However, within the scope of the invention the digital watermark is not present in the signal, as only its imprint is present in the digital signal and authenticates the signal.
By way of simplification, the case is disclosed where the digital watermark is defined by a sequence of symbols q(nT), T representing the time interval separating two consecutive symbols, and can be represented by a non-zero vector q constituted by complex variables corresponding to the symbols of the digital watermark, said complex variables being ordered according to the temporal ordering of the symbols of the digital watermark.
Preferably, the digital watermark is normalised such that the hermitian scalar product of the vector q corresponding to the dig q = 1
In other terms, noting Q the matrix corresponding to the vector q, the product of the transposed conjugated matrix QH of the vector q with the matrix Q of the vector q, is equal to the unit:
Qh x Q = 1
Hereinbelow, the hermitian scalar product designates such an operation between matrices corresponding to the vectors intervening in said hermitian scalar product.
This hermitian scalar product is also sometimes noted in a form explaining its hermitian character:
In reference to figure 2, the electronic emission system 1 acquires (step S1) the signal to be transmitted, which can be transmitted to the electronic emission system 1 in digital form, or else directly acquired by the electronic emission system 1, for example by means of a micro.
The electronic emission system 1, more precisely its processor 12, then projects (step S2) the vector s corresponding to the digital signal to be transmitted onto a vectorial space, said vectorial space being orthogonal to at least one non-zero vector q corresponding to a sequence of symbols defining a digital watermark.
In noting rP the vector corresponding to the digital signal resulting from the projection, In the identity matrix of dimensions ΝχΝ, and qH the conjugated transposed (or hermitian) vector of the vector q, this gives:
In the case of "negatively" superposing a set of K digital watermarks, by means of vectors qb i = 1...K, the vector s corresponding to a digital signal to be transmitted taking the form of a sequence of N symbols is projected onto a vectorial space, said vectorial space being orthogonal to a plurality of K non-zero vectors q· forming an orthogonal base, obtained by means of the Gram-Schmidt algorithm from the nonzero vectors qf each corresponding to a sequence of symbols defining a digital watermark:
The signal resulting from the projection can be determined as being the first column of the generalised inverse, called Penrose pseudo-inverse, of the matrix M of the following dimensions (Κ+1)χΝ:
with T the time interval separating two consecutive symbols.
The digital signal resulting from the projection rP is then normalised such that the hermitian scalar product of the vector s corresponding to the signal to be transmitted with the vector fTX corresponding to the digital signal transmitted is equal to N:
The digital signal transmitted rTx(nT) is then filtered to obtain the sent signal modulated in base band, which is sent by the electronic system by means of its signal emission chain 16 (step S3).
In reference to figure 3, the electronic reception system 2 acquires (step S4), by means of its reception chain 26, a signal corresponding to the signal transmitted by the electronic emission system 1. The electronic reception system 2 demodulates the signal to produce a received digital signal rRX(nT).
The electronic reception system 2, or more precisely its processor 22, authenticates the received digital signal by verifying (step S5) the orthogonality of a vector fRX, corresponding to said received digital signal and taking the form of a sequence of symbols, relative to said at least one vector q non-zero corresponding to a sequence of symbols defining the digital watermark.
Of course, in the event where a set of K digital watermarks is used, the electronic reception system authenticates a received digital signal by verifying orthogonality of a vector fRX, corresponding to said received digital signal and taking the form of a
sequence of symbols, relative to the plurality K of non-zero vectors q, each corresponding to a sequence of symbols defining a digital watermark.
The digital watermark(s) correspond to those used by the electronic reception system and respond consequently to the same definitions and requisites. So, the digital watermark or the digital watermarks can be stored in the form of local copies in the memory 24 of the electronic reception system 2, or the sequence of symbols defining said at least one digital watermark can result from transformation of symbols of the received digital signal.
To verify orthogonality, the electronic reception system 2 calculates a norm of the hermitian scalar product between said at least one vector q defining a digital watermark and the vector rRX corresponding to said received digital signal. The calculated norm is preferably the absolute value, but can be selected different.
The norm now calculated is compared to a determination threshold TSnr- This determination threshold Tsnr verifies the orthogonality between the vector rRX corresponding to the received digital signal and the vector or the vectors q, each corresponding to a digital watermark.
The electronic reception system 2 determines that the vector rRX corresponding to said received digital signal is orthogonal to said at least one vector q defining a digital watermark when said norm is less than the determination threshold Tsnr:
In the event where several digital watermarks are used:
Inversely, the electronic reception system 2 determines that the vector rRX corresponding to said received digital signal is not orthogonal to said at least one
vector q defining a digital watermark when said norm is greater than the determination threshold TSnr-
In fact, the received digital signal, if authentic, comes from a digital signal resulting from orthogonal projection on a vectorial space orthogonal to the digital watermarks, and, ideally, the vectors corresponding respectively to the received digital signal and to a digital watermark are orthogonal:
In reality, due especially to the noise introduced via the transmission channel between the electronic emission system 1 and the electronic reception system 2, the vector rRX corresponding to the received digital signal is not purely orthogonal to a vector q defining a digital watermark.
Consequently, the determination threshold TSnr is selected so as not to take into account the noise in the digital signal during calculation of the hermitian scalar product. The electronic reception system 2 preferably estimates a signal-to-noise ratio of the received digital signal, from which the determination threshold is fixed.
The electronic reception system 2 determines the authenticity (step S6) as a function of the result of verification of orthogonality. If the received digital signal is determined as orthogonal to the vectors each defining a watermark, the received digital signal is considered as authentic.
Throughout this specification and the claims which follow, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” and “comprising”, will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.
The reference in this specification to any prior publication (or information derived from
it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.
Claims (15)
- Claims Defining the Invention1. A method for emission of a digital signal, in which an electronic emission system performs the steps according to which: - a vector s corresponding to a digital signal to be transmitted taking the form of a sequence of N symbols is projected onto a vectorial space, said vectorial space being orthogonal to at least one non-zero vector q corresponding to a sequence of symbols defining a digital watermark, - the digital signal resulting from the projection is sent to an electronic reception system able to authenticate a received digital signal by verifying the orthogonality of a vector rRX, corresponding to said received digital signal and taking the form of a sequence of symbols, relative to at the least one non-zero vector q corresponding to the sequence of symbols defining the digital watermark.
- 2. The emission method of a digital signal according to the preceding claim, further comprising a step according to which, prior to its transmission, the digital signal resulting from the projection is normalised such that a Hermitian scalar product of the vector s corresponding to the signal to be transmitted with the vector fTX corresponding to the digital signal transmitted is equal to N.
- 3. The method according to any one of the preceding claims, wherein the vector s corresponding to a digital signal to be transmitted taking the form of a sequence of N symbols is projected onto a vectorial space, said vectorial space being orthogonal to a non-zero plurality of K vectors each corresponding to a sequence of symbols defining a digital watermark.
- 4. The method according to the preceding claim, wherein the signal resulting from the projection is determined as being the first column of the generalised inverse, called Penrose pseudo-inverse, of the following matrix M of dimensions (Κ+1)χΝ:with T the time interval separating two consecutive symbols.
- 5. The method according to any one of claims 1 to 4, wherein the sequence of symbols defining said at least one digital watermark results from transformation of symbols of the digital signal to be transmitted.
- 6. A method for reception of a digital signal, wherein an electronic reception system: - receives a digital signal sent by an electronic emission system, said digital signal resulting from the projection of a vector s corresponding to a digital signal to be transmitted taking the form of a sequence of N symbols onto a vectorial space, said vectorial space being orthogonal to at least one non-zero vector q corresponding to a sequence of symbols defining a digital watermark, and - authenticates the received digital signal by verifying the orthogonality of a vector rRX, corresponding to said received digital signal and taking the form of a sequence of symbols, relative to at least one non-zero vector q corresponding to the sequence of symbols defining the digital watermark.
- 7. The reception method according to the preceding claim, wherein, to verify orthogonality, the electronic reception system: - calculates a norm of a Hermitian scalar product between said at least one vector q defining a digital watermark and the vector rRX corresponding to said received digital signal, - compares said norm to a determination threshold, - determines that the vector rRX corresponding to said received digital signal is orthogonal to said at least one vector q defining a digital watermark when said norm is less than the determination threshold, and- determines that the vector rRX corresponding to said received digital signal is not orthogonal to said at least one vector q defining a digital watermark when said norm is greater than the determination threshold.
- 8. The reception method according to any one of claims 6 or 7, wherein the electronic reception system authenticates a received digital signal by verifying the orthogonality of a vector rRX, corresponding to said received digital signal and taking the form of a sequence of symbols, relative to a non-zero plurality K of vectors eg each corresponding to a sequence of symbols defining a digital watermark.
- 9. The reception method according to the preceding claim, comprising an estimation step of a signal-to-noise ratio of the received digital signal by the electronic reception system, said determination threshold being fixed as a function of said estimation.
- 10. The method according to any one of claims 6 to 9, wherein the sequence of symbols defining said at least one digital watermark results from transformation of symbols of the received digital signal.
- 11. The method according to any one of the preceding claims, wherein the digital watermark is normalised such that a Hermitian scalar product of the vector q corresponding to the digital watermark with itself is equal to one.
- 12. An electronic emission system comprising a processor, a memory and an emission chain, characterized in that the electronic emission system is configured to: - project a vector s corresponding to a digital signal to be transmitted taking the form of a sequence of N symbols onto a vectorial space, said vectorial space being orthogonal to at least one non-zero vector q corresponding to a sequence of symbols defining a digital watermark, - send the digital signal resulting from the projection in the form of a transmitted digital signal to an electronic reception system able to authenticate a received digital signal by verifying the orthogonality of a vector rRX, corresponding to said received digital signal and taking the form of a sequence of symbols, relative to at the least one non-zero vector q corresponding to the sequence of symbols defining the digital watermark.
- 13. An electronic reception system, comprising a processor, a memory and an acquisition chain, characterized in that the electronic reception system is configured to: - receive a digital signal sent by an electronic emission system, said digital signal resulting from the projection of a vector s corresponding to a digital signal to be transmitted taking the form of a sequence of N symbols onto a vectorial space, said vectorial space being orthogonal to at least one non-zero vector q corresponding to a sequence of symbols defining a digital watermark, and - verify the orthogonality of a vector fRX corresponding to said received digital signal with at least one non-zero vector q corresponding to the sequence of symbols defining the digital watermark.
- 14. The electronic reception system according to the preceding claim, wherein, to verify orthogonality, the electronic reception system is configured to: - calculate a norm of a Hermitian scalar product between said at least one vector q defining a digital watermark and the vector fRX corresponding to said received digital signal, - compare said norm to a determination threshold, - determine that the vector fRX corresponding to said received digital signal is orthogonal to said at least one vector q corresponding to the digital watermark when said norm is less than the determination threshold, and - determine that the vector fRX corresponding to said received digital signal is not orthogonal to the vector q corresponding to the digital watermark when said norm is greater than the determination threshold.
- 15. A computer program product comprising program code instructions for execution of the steps of the method according to any one of claims 1 to 11, when said program is run by a processor.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR1259445A FR2996717B1 (en) | 2012-10-04 | 2012-10-04 | INCRUSTATION OF A DIGITAL FILIGRANE IN A SIGNAL |
| FR1259445 | 2012-10-04 | ||
| PCT/EP2013/070727 WO2014053641A1 (en) | 2012-10-04 | 2013-10-04 | Embedding a digital watermark in a signal |
Publications (2)
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|---|---|
| AU2013326454A1 AU2013326454A1 (en) | 2015-05-07 |
| AU2013326454B2 true AU2013326454B2 (en) | 2018-11-08 |
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| Application Number | Title | Priority Date | Filing Date |
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| AU2013326454A Active AU2013326454B2 (en) | 2012-10-04 | 2013-10-04 | Embedding a digital watermark in a signal |
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| Country | Link |
|---|---|
| EP (1) | EP2904579B1 (en) |
| CN (1) | CN104919489B (en) |
| AU (1) | AU2013326454B2 (en) |
| BR (1) | BR112015007541A2 (en) |
| CA (1) | CA2886557A1 (en) |
| FR (1) | FR2996717B1 (en) |
| RU (1) | RU2015116625A (en) |
| WO (1) | WO2014053641A1 (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20030086585A1 (en) * | 1993-11-18 | 2003-05-08 | Rhoads Geoffrey B. | Embedding auxiliary signal with multiple components into media signals |
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| CN101189825A (en) * | 2005-01-12 | 2008-05-28 | 美商内数位科技公司 | Method and device for increasing wireless communication security |
| JP4118279B2 (en) * | 2005-03-11 | 2008-07-16 | 株式会社東芝 | Digital watermark detection apparatus and method |
| WO2007149621A2 (en) * | 2006-04-19 | 2007-12-27 | Cornell Research Foundation, Inc. | Methods and systems for object identification and for authentication |
| KR101135472B1 (en) * | 2010-02-03 | 2012-04-19 | 금오공과대학교 산학협력단 | Reversible watermark inserting, extracting and original contents restoring methods using difference histogram |
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- 2012-10-04 FR FR1259445A patent/FR2996717B1/en not_active Expired - Fee Related
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2013
- 2013-10-04 EP EP13773252.5A patent/EP2904579B1/en active Active
- 2013-10-04 CN CN201380052351.0A patent/CN104919489B/en active Active
- 2013-10-04 RU RU2015116625A patent/RU2015116625A/en unknown
- 2013-10-04 BR BR112015007541A patent/BR112015007541A2/en not_active Application Discontinuation
- 2013-10-04 WO PCT/EP2013/070727 patent/WO2014053641A1/en not_active Ceased
- 2013-10-04 CA CA 2886557 patent/CA2886557A1/en not_active Abandoned
- 2013-10-04 AU AU2013326454A patent/AU2013326454B2/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20030086585A1 (en) * | 1993-11-18 | 2003-05-08 | Rhoads Geoffrey B. | Embedding auxiliary signal with multiple components into media signals |
Non-Patent Citations (1)
| Title |
|---|
| PROAKIS, J. G.: "Digital Communications", Fourth Edition, 2000, McGraw-Hill, USA, pages 158-178 * |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2996717A1 (en) | 2014-04-11 |
| EP2904579B1 (en) | 2019-02-27 |
| AU2013326454A1 (en) | 2015-05-07 |
| CN104919489B (en) | 2018-07-10 |
| RU2015116625A (en) | 2016-11-27 |
| WO2014053641A1 (en) | 2014-04-10 |
| CN104919489A (en) | 2015-09-16 |
| BR112015007541A2 (en) | 2017-07-04 |
| CA2886557A1 (en) | 2014-04-10 |
| FR2996717B1 (en) | 2014-12-12 |
| EP2904579A1 (en) | 2015-08-12 |
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