KR20200119649A - Transmitting apparatus, receiveing apparatus and method for protecting video - Google Patents

Abstract

Disclosed are a transmitting apparatus, a receiving apparatus, and a method for protecting a video. A video protection method according to one embodiment of the present invention, as a video protection method of a transmitting apparatus and a receiving apparatus, comprises the steps of: allowing the transmitting apparatus for protecting the video to encode inputted video data into bitstream data, to perform selective encoding for encoding only portions of the bitstream data based on the type of profile and encryption elements and to transmit the bitstream data, resulted from performing the selective encoding, to the video receiving apparatus; and allowing the video receiving apparatus to receive the bitstream data resulted from performing the selective encoding, to decode an area, wherein only a part of the bitstream data has been encoded, based on the type of profile and the encryption elements, and to restore the video data from the decoded bitstream data.

Description

Video protection transmitting device, receiving device and method {TRANSMITTING APPARATUS, RECEIVEING APPARATUS AND METHOD FOR PROTECTING VIDEO}

The present invention relates to video processing, video transmission/reception, and video encryption/decryption technology, and more particularly, to a technology for providing real-time live broadcasting of encrypted/decrypted video and ensuring confidentiality of streaming service stored video.

CCTV and IoT devices located throughout society play a crucial role in preventing, detecting, and solving incidents of various crimes, and their use continues to increase while providing convenience for users' lives. However, technological advances such as illegal installation of image information processors and miniaturization of cameras are demanding improvement of problems that arise from abuse of crime.

Due to the nature of information, personal image information is easy to identify the subject of information, is vulnerable to illegal distribution, and is sensitive information that may cause shame and disgust of the subject of information due to the leakage of images, so more attention is required to protect it. Therefore, in the case of current video information such as CCTV video, it is regulated by current laws and various laws such as the Personal Video Information Protection Act are also coming into effect.

Existing video protection technologies have provided various solutions in the transmission process (SSL over HTTP (HTTPS), Secure Socket Layer-Virtual Private Network (SSL-VPN), etc.) or storage (Data full encryption). However, the protection technology in the transmission process does not guarantee the safety in the camera terminal or the storage server, and the entire encryption of data damages the image format and provides a limit to hinder execution.

In the end, video information, unlike other personal information, is the process of collecting information through'shooting', so there is a technical peculiarity that it cannot be notified or consented to the information subject individually. There is a desperate need for a systematic image protection system and method that can protect the entire cycle of people.

Meanwhile, Korean Patent Laid-Open Publication No. 10-2008-0028674 “An apparatus and method for protecting a video broadcasting program in the format of H.26 4” prevents broadcast streams from illegally distributing by stealing network packets and illegally watching or storing broadcasts. Disclosed is an apparatus and method for protecting a video broadcast program in H.264 format in which an original broadcast stream is encrypted and multicasted in real time for protection, and a desired channel and program can be selected and viewed by a client.

An object of the present invention is to provide a structured image protection that regulates illegal use from the photographing stage.

In addition, an object of the present invention is to block an act of damaging personal honor or infringing on an individual's intellectual property rights by distributing personal image information captured through a real-time image encryption/decryption system through an information communication network.

In addition, an object of the present invention is to impart confidentiality and integrity to image data in order to prevent external leakage and malicious forgery and alteration of image data.

In addition, an object of the present invention is to protect transmitted/stored images collected and distributed online in the entire cycle.

In addition, an object of the present invention is to provide a video protection method that maintains a compression rate based on an H.264 codec.

In addition, an object of the present invention is to protect an image that complies with a compression codec format.

An image protection method according to an embodiment of the present invention for achieving the above object is an image protection method of an image protection transmission device and an image reception device, wherein the image protection transmission device converts the received image data into bitstream data. Encoding, performing selective encryption of encrypting only a part of the bitstream data based on a profile type and encryption element, and transmitting the selectively encrypted bitstream data to the image receiving device, and the image receiving device A, receiving the bitstream data on which the selective encryption has been performed, decrypts a region in which only part of the bitstream data is encrypted based on a profile type and encryption element, and the image from the bitstream data decrypted by the selective encryption And restoring the data.

The present invention can provide systematic image protection that regulates illegal use from the photographing stage.

In addition, according to the present invention, personal image information captured through a real-time image encryption/decryption system can be disseminated through an information and communication network, thereby damaging personal honor or infringing on an individual's intellectual property rights.

In addition, the present invention may impart confidentiality and integrity to image data to prevent external leakage and malicious forgery or alteration of image data.

In addition, the present invention can protect transmitted/stored images collected and distributed online in the entire cycle.

In addition, the present invention can provide a video protection method that maintains a compression rate based on an H.264 codec.

In addition, the present invention can protect an image conforming to the compression codec format.

1 is a block diagram showing an image protection system according to an embodiment of the present invention.
2 and 3 are diagrams illustrating an encoding process of an H.264 codec-based encoder according to an embodiment of the present invention.
4 is a diagram showing an H.264 codec-based selective encryption scheme according to an embodiment of the present invention.
5 is a block diagram showing a video protection transmission apparatus according to an embodiment of the present invention.
6 is a detailed block diagram illustrating an example of an image encoder shown in FIG. 5.
7 is a detailed block diagram illustrating an example of the encryption unit shown in FIG. 5.
8 to 10 are diagrams showing an encryption element and an encryption method for a baseline profile according to an embodiment of the present invention.
11 and 12 are diagrams showing an encryption element and an encryption method for a Main/High profile according to an embodiment of the present invention.
13 is a flowchart illustrating an operation of a method for transmitting video protection according to an embodiment of the present invention.
FIG. 14 is a detailed operation flow diagram illustrating an example of an image encoding step shown in FIG. 13.
15 is an operation flow diagram showing in detail an example of the encryption step shown in FIG. 13.
16 is a block diagram showing a video protection receiving apparatus according to an embodiment of the present invention.
17 is a block diagram showing in detail an example of an encryption decryption unit shown in FIG. 16.
18 is a detailed block diagram illustrating an example of an image decoding unit shown in FIG. 16.
19 is a diagram illustrating an H.264 codec baseline profile-based selective decoding technique according to an embodiment of the present invention.
20 is a diagram illustrating a selective decoding scheme based on H.264 codec Main/High profile according to an embodiment of the present invention.
21 is an operation flow diagram illustrating a method of receiving video protection according to an embodiment of the present invention.
FIG. 22 is a detailed operational flow diagram illustrating an example of the encryption decryption step shown in FIG. 21.
23 is a detailed operation flow diagram illustrating an example of the image decoding step shown in FIG. 21.
24 is a diagram showing a computer system according to an embodiment of the present invention.

The present invention will be described in detail with reference to the accompanying drawings as follows. Here, repeated descriptions, well-known functions that may unnecessarily obscure the subject matter of the present invention, and detailed descriptions of configurations are omitted. Embodiments of the present invention are provided to more completely explain the present invention to those with average knowledge in the art. Accordingly, the shapes and sizes of elements in the drawings may be exaggerated for clearer explanation.

Throughout the specification, when a part "includes" a certain component, it means that other components may be further included rather than excluding other components unless specifically stated to the contrary.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The H.264 encoding technology according to an embodiment of the present invention may perform image compression according to a profile set so that only specific technologies can be used according to a usage area. This is a main profile consisting of technologies to maximize the compression ratio and a baseline profile suitable for low power and low resolution such as mobile broadcasting, and a high profile for higher quality video and technologies suitable for streaming environment. The added extended profile can be used selectively, and several new profiles can be added afterwards.

The present invention proposes an image encryption/decoding method based on an H.264 codec that provides an optimized compression rate according to a terminal specification for the purpose of protecting an image input in real time to a terminal having various capabilities.

1 is a block diagram showing an image protection system according to an embodiment of the present invention.

Referring to FIG. 1, it can be seen that an image protection system according to an embodiment of the present invention shows a system for the purpose of real-time image protection. Video input terminals that process video media can include a variety of terminals ranging from low-end (smartphone, black box, Jetson TX2, etc.) to high-end (CCTV, broadcasting camera), and input video data utilizes H.264 codec. Can be compressed. Afterwards, the compressed bitstream data is encrypted so that there is no damage to the compression rate through H.264 codec analysis, and it is stored in a state where video recognition is impossible, or it will be provided to the user in an encrypted/decrypted state through a video server or a player such as a smartphone. I can.

In other words, the image encryption can be applied to a terminal such as a CCTV, a black box, etc. through a compression process at the same time as input, and the image decryption provides a decrypted image by a user's key allowed in the image receiving server or user terminal. can do. An image protection system that performs image encryption and decoding can provide full-cycle protection of transmitted and stored images collected and distributed online.

In more detail, the application location selection criterion may be divided again as shown in FIGS. 2 and 3 according to whether or not the standardized H.264 codec is changed.

2 and 3 are diagrams illustrating an encoding process of an H.264 codec-based encoder according to an embodiment of the present invention.

Referring to FIG. 2, when encryption is included by changing the standard H.264 codec itself, an encryption code can be inserted in the entropy coding step. Referring to FIG. 3, when it is desired to avoid modification of the standard codec, Encryption can be performed without damage to the standard codec by using a separate parser (Nal unit Analysis) that analyzes the entropy-coded bitstream and inserts the encryption code. Therefore, it can be seen that the standard codec is directly modified or the standard codec is damaged by using a parser to select and apply the encryption.

4 is a diagram showing an H.264 codec-based selective encryption scheme according to an embodiment of the present invention.

Referring to FIG. 4, the present invention may select an element to be encrypted as a second element. It can be seen that, based on the characteristics of the H.264 codec, a selective encryption technique that encrypts only part of the data rather than all data is used. As shown in FIG. 4, selective encryption analyzes the compression characteristics of the H.264 codec and encrypts only important characteristic information in the image, thereby preventing the entire image from being recognized.

In order to select H.264 codec characteristic information for encryption according to an embodiment of the present invention, an area without damage to the H.264 codec compression rate or an area that can be minimized may be selected. In the present invention, the sign value (+,-) of IPM (Intra Prediction Mode), MVD (Motion Vector Difference), the sign value of trailing ones (T1s) and VLCN are extracted from the parameters encoded by CAVLC as a region without damage to the compression rate and encrypted. can do. In addition, in the encoding process, a region having a fixed length may include feature information for encryption.

5 is a block diagram showing a video protection transmission apparatus according to an embodiment of the present invention. 6 is a detailed block diagram illustrating an example of an image encoder shown in FIG. 5. 7 is a detailed block diagram illustrating an example of the encryption unit shown in FIG. 5.

Referring to FIG. 5, an image protection transmission device according to an embodiment of the present invention includes an image input unit 110, an image encoder 120, an encryption unit 130, and an image transmission unit 140.

The image input unit 110 may receive image data.

The image encoder 120 may compress image data.

In this case, the image encoder 120 may compress the image data using an H.264 codec and generate bitstream data.

Referring to FIG. 6, the image encoder 120 may include a prediction unit 121, a quantization unit 122, and an entropy encoder 123.

The predictor 121 may generate a prediction value from the image data and encode the image data.

The quantization unit 122 may binarize the image data through quantization of the image data.

The entropy encoder 123 may entropy-encode the image data based on the length of the code representing the symbol of the image data.

In this case, the entropy encoder 123 may encrypt the bitstream data using a selective encryption technique that encrypts only part of the image data based on the Baseline profile or the Main profile when the image protection transmission device does not use a parser. .

In this case, encryption may be applied to the Baseline profile and the Main profile through the entropy encoding process or immediately after the codec internal modification.

The encryption unit 130 may encrypt the bitstream data using a selective encryption technique that encrypts only a part of the bitstream data based on the encryption element.

In this case, the encryption unit 130 may apply selective encryption after analyzing the NAL unit through the parser when the video protection transmission device uses a parser, when using the baseline profile, and when using the main profile, as shown in FIG. As described above, CABAC encoding and CABAC decoding may be performed after NAL unit analysis.

In this case, CAVLC may be used as the Baseline profile and CABAC may be used as the Main profile.

In more detail, referring to FIG. 7 to describe the selective encryption using the Main profile, the encryption unit 130 includes a bitstream analysis unit 131, a CABAC decoding unit 132, an optional encryption unit 133, and a CABAC encoding unit ( 134) may be included.

The bitstream analysis unit 131 may analyze the NAL unit through a parser.

The CABAC decoder 132 may decode CABAC coded bitstream data.

The selective encryption unit 133 may perform selective encryption on the CABAC-decrypted bitstream data based on the encryption element.

The CABAC encoder 134 may CABAC-encode the selectively encrypted bitstream data.

That is, the selective encryption based on the baseline profile may be performed by the entropy encoding unit 123 of the image encoding unit 120, and the selective encryption based on the Main/High profile is performed by the encryption unit 130 including a parser. Can be done.

That is, the entropy encoding unit 123 and the encryption unit 130 may perform selective encryption based on the type of profile and the encryption element.

In this case, the entropy encoding unit 123 and the encryption unit 130 may perform selective encryption according to whether or not a parser included in the image protection transmission device is used.

The image transmission unit 140 may transmit encrypted bitstream data.

8 to 10 are diagrams showing an encryption element and an encryption method for a baseline profile according to an embodiment of the present invention.

8 to 10, the baseline profile according to an embodiment of the present invention is characterized by using an encryption key as encoding is performed based on an I/P frame and a context-based adaptive variable length coding (CAVLC). Information can be encrypted by Ex-Oring. For example, if the bit to be encrypted and the bit of the key are the same, they can be kept as they are, and if they are different, the bit value can be inverted. When the encryption module is executed in the parser of FIG. 8, it can be seen that an example of an encryption method according to an encryption element is shown. As IPM of Intra-MB (macroblock) and MV of Inter-MB are encoded using a fixed-length or Exp-golomb code, the suffix portion marked in blue in a fixed length or table can be encrypted using an encryption key. have. Residual data is encoded using CAVLC, and only trailing one (sign bit) with no change in length and the suffix part of the level can be encrypted so that there is no change in length after encryption.

In this case, when the apparatus for transmitting image protection does not use a parser, the bitstream data may be encrypted by using a selective encryption technique that encrypts only a part of the image data based on the baseline profile.

In this case, encryption may be applied to the baseline profile through the entropy encoding process or immediately after the codec internal modification.

In this case, when using a parser or when using a baseline profile, the video protection transmission apparatus may analyze the NAL unit through the parser and apply selective encryption.

11 and 12 are diagrams showing an encryption element and an encryption method for a Main/High profile according to an embodiment of the present invention.

11 and 12, the Main/High profile according to an embodiment of the present invention is based on an I/P/B frame and a context-based Adaptive Binary Arithmetic Coding (CABAC). There can be a difference in the way. As entropy coding of CABAC uses an arithmetic coding scheme, finding a designated location and encrypting it has difficulty in decryption, so encryption may be performed in a step after binarization before arithmetic coding. When the encryption module is executed in the parser of FIG. 11, it can be seen that an example of an encryption element and an encryption method for CABAC is shown. As shown in FIG. 2, when encryption is applied to a standard codec without using a parser, an encryption module may be installed before CABAC coding after binarization in the standard codec. However, in the case of using a parser as shown in FIG. 3, a module that performs CABAC Encoding after CABAC Decoding the CABAC-coded bitstream after analyzing the NAL unit in the parser as shown in FIGS. 11 and 12 and encrypting the binary encryption element. Must be loaded. Therefore, while the Baseline profile encryption is the same as the original standard codec compression rate, the Main/High profile encryption may lead to an increase in the compression rate.

In this case, when the apparatus for transmitting image protection does not use a parser, the bitstream data may be encrypted using a selective encryption technique that encrypts only a part of the image data based on the Main profile.

In this case, encryption may be applied to the main profile through the entropy encoding process or immediately after the codec internal modification.

In this case, the image protection transmission apparatus may encrypt the bitstream data by using a selective encryption technique that encrypts only a part of the bitstream data based on the encryption element.

In this case, when the video protection transmission device uses a parser, and when the main profile is used, the video protection transmission device may perform CABAC encoding and CABAC decoding after analyzing the NAL unit as illustrated in FIG. 7.

13 is a flowchart illustrating an operation of a method for transmitting video protection according to an embodiment of the present invention. FIG. 14 is a detailed operation flow diagram illustrating an example of an image encoding step shown in FIG. 13. 15 is an operation flow diagram showing in detail an example of the encryption step shown in FIG. 13.

Referring to FIG. 13, in the image protection transmission method according to an embodiment of the present invention, an image may be first input (S210).

In addition, the image protection transmission method according to an embodiment of the present invention may perform image encoding for compressing image data (S220).

That is, in step S220, the image data may be compressed using the H.264 codec and bitstream data may be generated.

Referring to FIG. 14, in step S220, a prediction value may be first generated from image data to encode image data (S221).

In addition, in step S220, the image data may be binarized through quantization of the image data (S222).

Further, in step S220, the image data may be entropy-encoded based on the length of the code representing the symbol of the image data (S223).

In this case, in step S223, when the image protection transmission apparatus does not use a parser, the bitstream data may be encrypted using a selective encryption technique for encrypting only a part of the image data based on the Baseline profile or the Main profile.

In this case, encryption may be applied to the Baseline profile and the Main profile through the entropy encoding process or immediately after the codec internal modification.

In addition, the image protection transmission method according to an embodiment of the present invention may perform encryption (S230).

That is, in step S230, the bitstream data may be encrypted using a selective encryption technique for encrypting only a part of the bitstream data based on the encryption element.

In this case, in step S230, when the video protection transmission apparatus uses a parser, when using a baseline profile, selective encryption may be applied after analyzing the NAL unit through the parser, and when using the main profile, as shown in FIG. Likewise, CABAC encoding and CABAC decoding can be performed after NAL unit analysis.

In this case, CAVLC may be used as the Baseline profile and CABAC may be used as the Main profile.

At this time, in step S230, when the video protection transmission apparatus uses a parser and uses the main profile, CABAC encoding and CABAC decoding may be performed after NAL unit analysis.

Referring to FIG. 15, in step S230, the NAL unit may be analyzed first through a parser (S231).

In addition, in step S230, the CABAC-coded bitstream data may be decoded (S232).

In addition, step S230 may perform selective encryption on the CABAC-decrypted bitstream data based on the encryption element (S233).

In addition, in step S230, the selectively encrypted bitstream data may be CABAC-encoded (S234).

In addition, the image protection transmission method according to an embodiment of the present invention may transmit an image (S240).

That is, step S240 may transmit the encrypted bitstream data.

An image protection receiving apparatus according to an embodiment of the present invention may also include a decryption method capable of providing an encrypted image as a decrypted image to an authorized user.

16 is a block diagram showing a video protection receiving apparatus according to an embodiment of the present invention. 17 is a block diagram showing in detail an example of an encryption decryption unit shown in FIG. 16. 18 is a detailed block diagram illustrating an example of an image decoding unit shown in FIG. 16.

Referring to FIG. 16, an image protection receiving apparatus according to an embodiment of the present invention may include an image receiving unit 310, a cryptographic decoding unit 320, an image decoding unit 330, and an image output unit 340. .

The image receiving unit 310 may receive encrypted bitstream data from the image protection transmission device.

The encryption/decryption unit 320 may decrypt the encrypted bitstream data using a selective encryption technique that encrypts only a portion of the image data.

At this time, the encryption/decryption unit 320 may apply selective encryption/decryption after analyzing the NAL unit through the parser when the video protection receiving device uses a parser, when using the baseline profile, and when using the main profile, analyze the NAL unit. Afterwards, CABAC decoding and CABAC encoding may be performed.

In this case, CAVLC may be used as the Baseline profile and CABAC may be used as the Main profile.

Referring to FIG. 17, the encryption decryption unit 320 may include a bitstream analysis unit 321, a CABAC encoding unit 322, an optional encryption unit 323, and a CABAC decoding unit 324.

The bitstream analysis unit 321 may perform Nal unit analysis of the parser.

The CABAC encoder 322 may CABAC-encode the CABAC-decoded bitstream data.

The selective encryption unit 323 may decrypt the selectively encrypted region of the CABAC-encoded bitstream data based on the encryption element.

The CABAC decryption unit 324 may CABAC decrypt bitstream data in which the selectively encrypted region is decrypted.

The image decoder 330 may generate image data by decoding bitstream data.

Referring to FIG. 18, the image decoding unit 330 may include an entropy decoding unit 331, an inverse quantization unit 332, and a prediction unit 333.

The entropy decoder 331 may entropy decode image data based on a length of a code representing a symbol of the bitstream data.

In this case, the entropy decoding unit 331 may decrypt the encrypted region of the selectively encrypted bitstream data based on the Baseline profile or the Main profile.

At this time, the entropy decoding unit 331 may decrypt the bitstream data using a selective encryption technique that encrypts only a part of the image data based on the Baseline profile or the Main profile when the image protection receiver does not use a parser. .

In this case, encryption may be applied to the Baseline profile and the Main profile through the entropy decoding process or immediately after the codec internal modification.

That is, the encryption decryption unit 320 and the entropy decryption unit 331 may decrypt a partial region of bitstream data for which selective encryption has been performed based on the type of the profile and the encryption element.

In this case, the encryption decryption unit 320 and the entropy decryption unit 331 may decrypt a partial region of the selectively encrypted bitstream data according to whether a parser included in the image protection receiving apparatus is used.

The inverse quantization unit 332 may restore image data through inverse quantization of bitstream data.

The prediction unit 333 may reconstruct image data by generating a prediction value from bitstream data.

That is, the decoding of the selectively encrypted bitstream data based on the baseline profile may be performed in the entropy decoding unit 331 of the image decoding unit 330, and the selective encryption based on the Main/High profile includes a parser. It may be performed by the encryption decryption unit 120.

The image output unit 340 may output the restored image data through a display.

When encryption is performed by changing the standard H.264 codec itself (FIG. 2), the baseline and the Main/High profile can be decrypted in the same manner in the encrypted part. In other words, the baseline profile is decoded in the entropy coding stage, and the main/high profile is binarized in the standard codec, and a decoding module is installed before CABAC coding.

On the other hand, when encryption is performed through an image analysis module (parser) in order to maintain the H.264 format compliance principle (Fig. 3), the image decryption is a parameter that is selectively partially encrypted after analyzing the image-encrypted bitstream through the parser. It is necessary to extract and perform decryption. Therefore, according to the profile, as shown in FIG. 18, it can be divided into sign decryption, IPM decryption, and MVD decryption.

19 is a diagram illustrating an H.264 codec baseline profile-based selective decoding technique according to an embodiment of the present invention.

Referring to FIG. 19, it can be seen that selective partial decoding for three regions information is applied in response to image encryption based on the H.264 codec baseline profile. The image protection reception method of FIG. 19 is a process in which an encrypted bitstream is decoded using selective partial decoding, and then the decoded bitstream is input to an image codec and may be reproduced in real time through a decoding process.

20 is a diagram illustrating a selective decoding scheme based on H.264 codec Main/High profile according to an embodiment of the present invention.

Referring to FIG. 20, decryption for the Main/High profile may decrypt data encrypted through a parser. In this case, the Parser may encode the CABAC Decoded data through Nal unit analysis, restore the region corresponding to FIGS. 11 and 12 as shown in FIG. 19, and then perform CABAC decoding again. Thereafter, the decoded bitstream can play an image in a decoded form through a decoder of a standard H.264 codec.

21 is an operation flow diagram illustrating a method of receiving video protection according to an embodiment of the present invention. FIG. 22 is a detailed operational flow diagram illustrating an example of the encryption decryption step shown in FIG. 21. 23 is a detailed operation flow diagram illustrating an example of the image decoding step shown in FIG. 21.

In the video protection receiving method according to an embodiment of the present invention, first, the encrypted bitstream data may be received from the video protection transmission device (S410).

In addition, the image protection reception method according to an embodiment of the present invention may perform encryption decoding (S420).

That is, in step S420, the encrypted bitstream data may be decrypted using a selective encryption technique for encrypting only part of the image data.

At this time, in step S420, when the video protection receiving device uses a parser, when using the baseline profile, after analyzing the NAL unit through the parser, selective encryption and decryption can be applied, and when using the main profile, after analyzing the NAL unit. CABAC decoding and CABAC encoding can be performed.

In this case, CAVLC may be used as the Baseline profile and CABAC may be used as the Main profile.

Referring to FIG. 22, in step S420, a bitstream may be first analyzed (S421).

That is, step S421 may perform the analysis of the Nal unit of the parser.

Further, in step S420, the CABAC-decoded bitstream data may be CABAC-encoded (S422).

Further, in step S420, the selectively encrypted region of the CABAC-encoded bitstream data may be decoded based on the encryption element (S423).

Further, in step S420, the bitstream data in which the selectively encrypted region is decrypted may be CABAC-decoded (S424).

In addition, the image protection reception method according to an embodiment of the present invention may perform image decoding (S430).

That is, in step S430, image data may be generated by decoding the bitstream data.

Referring to FIG. 23, in step S430, first, image data may be entropy-decoded based on a length of a code representing a symbol of bitstream data (S431).

In this case, in step S431, the encrypted region of the selectively encrypted bitstream data based on the Baseline profile or the Main profile may be decrypted.

In this case, in step S431, when the image protection receiving apparatus does not use a parser, the bitstream data may be decrypted using a selective encryption technique that encrypts only a part of the image data based on the baseline profile or the main profile.

In this case, encryption may be applied to the Baseline profile and the Main profile through the entropy decoding process or immediately after the codec internal modification.

Further, in step S430, the image data may be restored through inverse quantization of the bitstream data (S432).

In addition, in step S430, the image data may be restored by generating a prediction value from the bitstream data (S433).

In addition, the image protection reception method according to an embodiment of the present invention may output an image (S440).

That is, in step S440, the reconstructed image data may be output through the display.

The video protection transmitting apparatus, receiving apparatus, and method according to an embodiment of the present invention provide a video protection technology capable of maintaining the compression rate as it is in the baseline profile encryption of the H.264/AVC codec and minimizing the compression rate damage in the main profile encryption Can provide. In addition, H.264/AVC compression codec format compliance provides the advantage of being able to monitor de-identified video with an existing video player, and proposes an encryption/decoding technique without damage to the standard codec using a parser. I can. In addition, it is possible to minimize the complexity and burden required for encryption/decryption by performing selective encryption that can be applied to a recent lightweight terminal.

24 is a diagram showing a computer system according to an embodiment of the present invention.

Referring to FIG. 24, the image protection transmission apparatus and the image protection reception apparatus according to an embodiment of the present invention may be implemented in a computer system 1100 such as a computer-readable recording medium. As shown in FIG. 24, the computer system 1100 includes at least one processor 1110, a memory 1130, a user interface input device 1140, and a user interface output device 1150 communicating with each other through a bus 1120. And a storage 1160. Also, the computer system 1100 may further include a network interface 1170 connected to the network 1180. The processor 1110 may be a central processing unit or a semiconductor device that executes processing instructions stored in the memory 1130 or the storage 1160. The memory 1130 and the storage 1160 may be various types of volatile or nonvolatile storage media. For example, the memory may include a ROM 1131 or a RAM 1132.

As described above, the image protection transmitting apparatus, receiving apparatus, and method according to an embodiment of the present invention are not limited to the configuration and method of the embodiments described as described above, but various modifications are made to the embodiments. All or part of each of the embodiments may be selectively combined and configured to be achieved.

110: video input unit 120: video code viewing unit
121: prediction unit 122: quantization unit
123: entropy encoding unit
130: encryption unit 131: bitstream analysis unit
132: CABAC decryption unit 133: optional encryption unit
134: CABAC encoding unit 140: image transmission unit
310: image receiving unit 320: encryption decoding unit
321: bitstream analysis unit 322: CABAC encoding unit
323: optional encryption unit 324: CABAC decryption unit
330: image decoding unit 331: entropy decoding unit
332: inverse quantization unit 333: prediction unit
340: video output unit
1100: computer system 1110: processor
1120: bus 1130: memory
1131: ROM 1132: RAM
1140: user interface input device
1150: user interface output device
1160: storage 1170: network interface
1180: network

Claims (1)

In the video protection transmission device and the video protection method of the video receiving device
The video protection transmission device encodes the received video data as bitstream data, performs selective encryption of encrypting only a part of the bitstream data based on a profile type and encryption element, and the selective encryption bit Transmitting stream data to the video receiving device; And
The image receiving device receives the bitstream data on which the selective encryption has been performed, decrypts a region in which only part of the bitstream data is encrypted based on the profile and the encryption element, and the image from the decoded bitstream data Restoring data;
Image protection method comprising a.

Images