Information masking device

Abstract

The utility model relates to information concealment devices. The technical result is an increased level of security for transmitted information. The information concealment device comprises a masked signal conversion unit, a key memory unit, first, second, third, fourth, and fifth summation units, first, second, third, and fourth multiplication units, and first and second division units. The input of the masked signal conversion unit is the first input of the device to which the information signal is supplied. 2 fig.

Description

[0001] The utility model relates to telecommunications and computing technology, to the field of methods and devices for steganographic data conversion, and can be used in communications, computing and information systems for steganographic concealment of information during data exchange between government, law enforcement, defense, banking and industrial institutions when there is a need to store and transmit confidential information.

[0002] A known radio masking device [1] can be considered as an analogue of the utility model. It contains a noise generator consisting of a system of two coupled oscillators, a capacitive coupling element between them, a radiating antenna and a low-frequency noise source. The first oscillator contains a nonlinear amplifier, a delay line and an inertial self-bias circuit. The output of the nonlinear amplifier is connected to the input via a delay line, the inertial self-bias circuit is connected between the common electrode of the active element of the nonlinear oscillator and the common bus. The second oscillator contains a nonlinear amplifier and an adjustable delay line. The output of the nonlinear amplifier is connected to the input via an adjustable delay line. The delay line provides adjustment of the position of the natural frequencies of this oscillator. The output of the first oscillator is connected to the input of the second oscillator using a capacitive coupling element. The element of the oscillatory system is a radiating antenna of the magnetic dipole type.The input of the first generator is connected to the output of a low-frequency noise source.

[0003] The disadvantage of the known device is the generation of noise by the receiving side, which limits the coverage area of ​​radio masking, as well as the use of the additive superposition principle, which reduces its resistance to attacks.

[0004] A device (prototype) for concealing information is known [2], comprising a masked signal conversion unit, a key memory unit, first, second and third summation units, first, second, third and fourth multiplication units, wherein the second input of the first summation unit is connected to the first output of the first key memory unit, the input of the masked signal conversion unit is the first input of the device to which an information signal is supplied, the first inverting input of the first summation unit is connected to the output of the masked signal conversion unit, the first input of the first multiplier is connected to the output of the masked signal conversion unit, and the second input is connected to the fourth output of the key memory unit, the first input of the second multiplier is connected to the output of the first summation unit, and the second input is connected to the fifth output of the key memory unit, the first input of the third multiplier is connected to the second input of the device to which a masking signal is supplied,the second input of the third multiplier is connected to the sixth output of the key memory unit, the first input of the fourth multiplier is connected to the seventh output of the key memory unit, and the second input is connected to the second input of the device, the first input of the second summation unit is connected to the output of the first multiplier, the second input of the second summation unit is connected to the second output of the key memory unit, the third input of the second summation unit is connected to the output of the third multiplier, the first input of the third summation unit is connected to the output of the second multiplier, the second input of the third summation unit is connected to the third output of the key memory unit, the third input of the third summation unit is connected to the output of the fourth multiplier, the output of the second summation unit is the first output of the device, the output of the third summation unit is the second output of the device.,

[0005] The disadvantage of the prototype is the linear masking model, due to the use of an algorithm based on the sum of linear functions of two signals.

[0006] The purpose of the utility model is to increase the level of security of transmitted information by using a nonlinear algorithm based on the relationship of linear functions of two signals with the placement of the informative signal in the numerator of the function and the use of an additive relationship of the embedded components.

[0007] For this purpose, in a known device comprising a masked signal conversion unit, a key memory unit, first, second and third summation units, first, second, third and fourth multiplication units, wherein the input of the masked signal conversion unit is the first input of the device to which an information signal is supplied, the first inverting input of the first summation unit is connected to the output of the masked signal conversion unit, the first input of the first multiplication unit is connected to the output of the masked signal conversion unit, the first input of the second multiplication unit is connected to the output of the first summation unit, the second input of the fourth multiplication unit is connected to the second input of the device to which a masking signal is supplied, the fourth and fifth summation units, the first and second division units are input, the first output of the key memory unit is connected to the first input of the second summation unit and to the first input of the third summation unit,the second output of the key memory unit is connected to the second input of the first summation unit, the third output of the key memory unit is connected to the second input of the first multiplication unit, the fourth output of the key memory unit is connected to the second input of the second multiplication unit, the fifth output of the key memory unit is connected to the first input of the fourth summation unit, the sixth output of the key memory unit is connected to the first input of the fifth summation unit, the seventh output of the key memory unit is connected to the first input of the third multiplication unit, the eighth output of the key memory unit is connected to the first input of the fourth multiplication unit, the second input of the third multiplication unit is connected to the second input of the device, the output of the first multiplication unit is connected to the second input of the second summation unit, the output of the second multiplication unit is connected to the second input of the third summation unit, the output of the third multiplication unit is connected to the second input of the fourth summation unit,the output of the fourth multiplication block is connected to the second input of the fifth summation block, the output of the second summation block is connected to the first input of the first division block, the output of the third summation block is connected to the first input of the second division block, the output of the fourth summation block is connected to the second input of the first division block, the output of the fifth summation block is connected to the second input of the second division block, the output of the first division block is the first output of the device, the output of the second division block is the second output of the device.,

[0008] The technical result that will be obtained when using the information hiding device is to increase the masking of the useful signal in an arbitrary noise signal.

[0009] Fig. 1 shows the structural diagram of the information concealment device (encoder). The device comprises a masking signal conversion unit 1, a key memory unit 2, five summation units 3, 8, 9, 10 and 11 respectively, four multiplication units 4, 5, 6 and 7 respectively, and two division units 12 and 13.

[0010] To restore the hidden signal, a decoder is used, shown in Fig. 2, containing a key memory block 14, multiplication blocks 15, 16, 17, 18, 19 and 20, summation blocks 21 and 22, division block 23.

[0011] The information masking device works as follows.

[0012] The hidden signal u is fed to the input of the device, where it is used to generate the signal u1=f(u) in block 1. Note that the transformation can consist of either transforming the bit information into a specific bit sequence or including a set of transformations (amplitude, cryptographic, etc.).

[0013] Next, using the encoder, which includes blocks 1-13, two signals y1 and y2 are generated and transmitted via the information transmission device. The mathematical description of the encoder is as follows [3]:

[0014] (1),

[0015] where signals u1 and u2 are related by the relation:

[0016] (2)

[0017] According to these expressions, the key memory block transmits the values ​​to the outputs, respectively: C, K, a1, a2, b1, b2, c1, c2, where C=1.

[0018] Signals y1 and y2 are the output signals of the information hiding device.

[0019] The signal is restored using a decoder, represented by blocks 14-23 in Fig. 2. Mathematically, the signal u1 is restored in accordance with the expression:

[0020] (3)

[0021] It can be noted that in expression (3), a large number of calculations affect the coefficients (keys) of the system. These calculations can be performed in advance by storing in memory the calculation results, respectively, K1, K2, K3, and K4, calculated according to the expressions:

[0022] ; (4)

[0023] ; (5)

[0024] (6)

[0025] (7)

[0026] Then expression (3) is transformed to the form:

[0027] (8)

[0028] According to these expressions, the key memory block transmits the values ​​to the outputs, respectively: K1, K2, K3, K4, c2.

[0029] Expressions (1) and (2) are the mathematical model of the encoder, expressions (4-8) are the mathematical model of the decoder.

[0030] The received signals y1 and y2 constitute a filled stegocontainer. A distinctive feature of the container formed in accordance with (1) is the presence of two signals that share a common masking component. This feature allows expression (8) to be used to open the container.

[0031] Thus, the proposed device can effectively mask the hidden signal in an arbitrary noise signal.

[0032] List of sources to be considered during the examination.

[0033] 1. Patent for invention No. 2170493. Russian Federation, IPC H04K. Radio masking device / V.A. Bezrukov, V.P. Ivanov, V.S. Kalashnikov, M.N. Lebedev / / Declared 15.05.2000; published 15.05.2001.

[0034] 2. Shakursky, M.V. Information concealment device / M.V. Shakursky / / Patent for utility model 237121 Russian Federation, IPC H04L 9 / 00. - declared 02 / 28 / 2025; published 09 / 11 / 2025 Bulletin No. 26.

[0035] 3. Shakursky, M.V. Compressive mappings in invariant converters and steganography systems / V.K. Shakursky, M.V. Shakursky / / Monograph. Publishing House of the Scientific Center of the Russian Academy of Sciences, Samara 2014., 159 p.

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