KR101145782B1 - Method for lightweight video contents encryption and decryption to provide mobile contents service - Google Patents

Abstract

The present invention relates to a method for encrypting and decrypting video content that is light in weight, and does not encrypt the entire video content at the service provider providing the mobile content service, thereby encrypting only a part of the video content, thereby transferring the mobile content service to the mobile terminal device. A mobile content service that can reduce overhead and time required in encryption process in a streaming server of a service provider to provide and decryption of encrypted video content in a mobile terminal device of a user using a mobile content service. To provide a lightweight video content encryption and decryption method for providing a computer and a computer-readable recording medium recording a program for realizing the method.
To this end, the present invention provides a video content encryption method, comprising: receiving a request for transmission of video content; Generating an encryption key for performing encryption using an encryption key generator; Detecting a stream having a type of Network Adaptation Layer (NAL) unit of Sequence Parameter Sets (SPS) among streams of the video content while transmitting the requested video content; And encrypting a raw byte sequence payload (RBSP) of the detected stream from the detected stream using the generated encryption key.

Description

Method for lightweight video contents encryption and decryption to provide mobile contents service}

The present invention relates to a lightweight video content encryption and decryption method for providing a mobile content service, and a computer readable recording medium having recorded thereon a program for realizing the method, and more particularly, to a mobile content service in a mobile terminal device. Lightweight video content encryption and decryption method to reduce unnecessary encryption and decryption time while avoiding unnecessary overhead by using a lightweight video content encryption and decryption scheme to provide (eg, IPTV service) And a computer readable recording medium having recorded thereon a program for realizing the method.

In the following exemplary embodiment of the present invention, an IPTV (Internet Protocol Television) service in a mobile terminal is described as an example of a mobile content service. However, the present invention is not limited thereto.

In the following embodiment of the present invention, MPEG-4 part 10 or H.264 / AVC (Advanced), which is a standard of a digital video codec provided by an IPTV service and has a high data compression rate, is an example of video content. Digital Coding Content encoded with Video Coding) will be described as an example, but the present invention is not limited thereto.

In general, the elements of the IPTV service are largely divided into the following two elements. The first is a service provider for producing and managing contents for an IPTV service, and the second is a service user receiving an IPTV service by the service provider. The network for such an IPTV service basically includes a contents server for managing contents at the service provider side, a license server for managing service users at the service provider, and a service at the service user side. It includes a wired set-top box (STB) which is a terminal device used for the purpose.

The IPTV service is a type of service that provides digital contents through a managed Internet Protocol (IP) based network that provides a level of Quality of Service (QoS), Quality of Emotion (QoE), security, and the like. Mobility technology is not applied.

Until now, a wired set-top box (STB) provided to a service user for an IPTV service is a hardware-based terminal device, which is a terminal device fixed once in a place once installed. In this IPTV service, the user owns a high-performance streamlined set-top box (STB) so that the user can receive high-quality services regardless of the performance of the terminal device, and how to provide QoS and QoE mainly for the IPTV service. There has been much research.

However, in recent years, in the field of IPTV service, interest in a new type of mobile IPTV (Mobile IPTV) service using wireless technology and mobility technology is increasing, and as a result, compared to a conventional high performance set top box (STB), a CPU (Central Processing Unit) There are many studies to optimize IPTV services for mobile terminals that lack resources such as performance, memory, and video resolution.

In such a service for mobile IPTV, security for content protection is an important technology element. That is, a technology for content protection in a mobile terminal device having low performance compared to a conventional STB is very important.

Resources such as CPU and memory of the existing STBs are optimized to provide high quality IPTV services with high video resolution. Meanwhile, even in a mobile terminal device, there is an alternative that can provide an IPTV service by lowering a high resolution content to a low resolution content. However, the existing encryption and decryption methods for protecting digital video content use a content whole encryption method and a decryption method. In order to use the terminal device to provide an IPTV service, the mobile terminal must provide a better resource, otherwise there is a problem in that overhead occurs while decrypting the encrypted content.

Looking at another example, the study was conducted for the digital content redistribution method, which is a method of receiving digital content only from a content server, but receiving the content from a terminal device of another user who has already downloaded the desired content. The content pre-encryption method is not a method of directly downloading content from a service provider, but a method of purchasing an encryption key that encrypts the content.

The conventional digital content redistribution method has a great advantage that the content redistribution has already been realized. However, the conventional digital content redistribution method also uses the encryption key to encrypt the entire content. There is a disadvantage in that a lot of overhead occurs while decrypting the content, and when the encryption key is exposed, the redistribution content cannot be protected, and thus the rights of the author having the content can no longer be guaranteed. .

Therefore, the prior art as described above has the same problems as described above, and it is a problem of the present invention to solve these problems.

Therefore, the present invention encrypts only some elements of the video content instead of encrypting the entire video content at the service provider providing the mobile content service, thereby encrypting the streaming server at the service provider side providing the mobile content service to the mobile terminal device. Lightweight video content encryption and decryption for providing mobile content services, which can reduce overhead and time required in decrypting encrypted video content in a mobile terminal device of a user side using the mobile content service It is an object of the present invention to provide a computer-readable recording medium having recorded thereon a method and a program for realizing the method.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention which are not mentioned can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

According to a first aspect of the present invention, there is provided a video content encryption method comprising: receiving a request for transmission of video content; Generating an encryption key for performing encryption using an encryption key generator; Detecting a stream having a type of Network Adaptation Layer (NAL) unit of Sequence Parameter Sets (SPS) among streams of the video content while transmitting the requested video content; And encrypting a raw byte sequence payload (RBSP) of the detected stream from the detected stream using the generated encryption key.

According to another aspect of the present invention, there is provided a video content decoding method comprising: requesting video content; Downloading an encryption key to be used to decrypt the video content; Detecting a stream having a type of Network Adaptation Layer (NAL) unit of Sequence Parameter Sets (SPS) from among streams of the video content while downloading and streaming the requested video content; And decrypting a Raw Byte Sequence Payload (RBSP) of the detected stream from the detected stream using the downloaded encryption key.

According to a third aspect of the present invention, there is provided a video content encryption method comprising: receiving a request for transmission of video content; Generating an encryption key for performing encryption using an encryption key generator; Detecting a stream having a type of Network Adaptation Layer (NAL) unit of Picture Parameter Sets (PPS) among streams of the video content while transmitting the requested video content; And encrypting a Raw Byte Sequence Payload (RBSP) of the PPS in the detected stream using the generated encryption key.

According to a fourth aspect of the present invention, there is provided a video content decoding method comprising: requesting video content; Downloading an encryption key to be used to decrypt the video content; Detecting a stream having a type of Network Adaptation Layer (NAL) unit of Picture Parameter Sets (PPS) from among streams of the video content while downloading and streaming the requested video content; And decrypting a Raw Byte Sequence Payload (RBSP) of the PPS from the detected stream using the downloaded encryption key.

On the other hand, the present invention, the content server, the step of receiving a request for the transmission of video content; Generating an encryption key for performing encryption using an encryption key generator; Detecting a stream having a type of Network Adaptation Layer (NAL) unit of Sequence Parameter Sets (SPS) among streams of the video content while transmitting the requested video content; And a computer-readable recording medium having recorded thereon a program for realizing an encryption step of encrypting a raw byte sequence payload (RBSP) of an SPS using the generated encryption key.

In addition, the present invention, the terminal device having a processor, the step of requesting the video content; Downloading an encryption key to be used to decrypt the video content; Detecting a stream having a type of Network Adaptation Layer (NAL) unit of Sequence Parameter Sets (SPS) from among streams of the video content while downloading and streaming the requested video content; And a computer-readable recording medium having recorded thereon a program for realizing a decryption step of decrypting a raw byte sequence payload (RBSP) of an SPS using the downloaded encryption key.

In addition, the present invention, the content server, the step of receiving a request for the transmission of video content; Generating an encryption key for performing encryption using an encryption key generator; Detecting a stream having a type of Network Adaptation Layer (NAL) unit of Picture Parameter Sets (PPS) among streams of the video content while transmitting the requested video content; And a computer readable recording medium having recorded thereon a program for realizing an encryption step of encrypting a raw byte sequence payload (RBSP) of a PPS using the generated encryption key among the detected streams.

In addition, the present invention, the terminal device having a processor, the step of requesting the video content; Downloading an encryption key to be used to decrypt the video content; Detecting a stream having a type of Network Adaptation Layer (NAL) unit of Picture Parameter Sets (PPS) from among streams of the video content while downloading and streaming the requested video content; And a computer-readable recording medium having recorded thereon a program for realizing a decryption step of decrypting a raw byte sequence payload (RBSP) of the PPS using the downloaded encryption key among the detected streams.

The present invention can be applied to a terminal device such as a set-top box (STB) for receiving an IPTV service, and in particular, in the case of a mobile terminal device for serving a mobile IPTV, resources of each mobile terminal device are also different from each other and a streamlined type for a general IPTV service. Since there are more limited resources such as CPU performance and memory than the STB, it is preferable to use a method of encrypting only some components of content during encryption and decryption. The present invention is applicable to security systems and solutions such as Digital Rights Management (DRM) and Conditional Access System (CAS) for IPTV services.

As described above, the present invention provides a streaming server of a service provider that provides a mobile IPTV service to a mobile terminal device by encrypting only some elements of the video content instead of encrypting the entire digital video content at the service provider that provides the IPTV service. The time required for the encryption process and the process of decrypting the encrypted digital video content in the mobile terminal of the user side using the mobile IPTV service can be reduced.

In addition, the present invention does not encrypt the entire digital video content (e.g., H.264 / AVC video content), but encrypts only the information necessary for decoding, such as Sequence Parameter Sets (SPS), among the digital video content. There is an effect of reducing the overhead incurred in the encryption process in the streaming server to provide and the process of decrypting the encrypted digital video content in the mobile terminal device of the user side using the mobile IPTV service.

In addition, the present invention has an effect that the encryption is not enough to decrypt the digital video content similarly to encrypting the entirety of the digital video content only by encrypting only some elements of the digital video content.

1 is a diagram showing a general IPTV network,
2 is a diagram illustrating a structure of a NAL unit in video content encoded in H.264 / AVC format among digital video contents;
3 is a diagram illustrating a NAL bit string in a video content encoded in H.264 / AVC format among digital video contents in a NAL unit type;
4 is a diagram illustrating an embodiment of a lightweight video content encryption method for providing a mobile content service according to the present invention;
5 is a structural diagram of a general IPTV communication model (IPTVCM: IPTV Communication Model),
6A is a flowchart illustrating an embodiment of a lightweight video content encryption method for providing a mobile content service according to the present invention;
6B is a flowchart illustrating an embodiment of a lightweight video content decoding method for providing a mobile content service according to the present invention;
7A and 7B are graphs illustrating results of execution time when encryption and decryption is performed on H.264 / AVC video content having 300 frames and a resolution of 176 × 144.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings, It can be easily carried out. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

And throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "electrically connected" with another part in between. Also, when a component is referred to as " comprising "or" comprising ", it does not exclude other components unless specifically stated to the contrary .

In order to understand the present invention, it is first necessary to understand the format of digital video content provided by a service provider. Currently, digital video content provided for IPTV service is encoded as a standard of digital video codec having a very high data compression rate called H.264. This standard of Digital Video CODEC is also called MPEG-4 Part 10 or H.264 / AVC (Advanced Video Coding), and is the International Telecommunication Union-Telecommunication standardization sector (ITU-T) and the International Organization for Standardization (ISO). The International Standards Council (IEC) and the International Institute of Electrical and Electronics Engineers (IEC) have jointly established standards for the compression, encoding, and multiplexing of encoded video and audio signals.

One of the characteristics of H.264 is a structure separated into a layer called a network adaptation layer (NAL), a layer existing between a video coding layer (VCL) that is a video encoding layer and a subsystem that transmits and stores encoded information. Is defined and configured. The output of the encoding process is VCL data (contiguous bits representing encoded video data), and the VCL data is mapped to NAL units before sending or storing. The NAL unit may be transmitted through a packet-based network or a bitstream transmission link or stored in a file. In this case, the purpose of separately defining the VCL and the NAL is to distinguish between the compression characteristics of the VCL and the transmission characteristics of the NAL.

1 is a diagram illustrating a general IPTV network.

As shown in FIG. 1, the most basic IPTV network is a basic component of a content server (Contents Server 11, 12) for managing content on the service provider side and a license server for managing a service user by the service provider (License). Server, 13, 14), and Set-Top Box (STB: 15, 16), which is a terminal device (Terminal Device) used to receive a service from the service user side.

Herein, the content servers 11 and 12 include a streaming server.

The set top boxes STBs 15 and 16 are generally fixed (wired) terminal devices, which are capable of providing high quality images and are connected to a large device such as a TV or a PC.

Meanwhile, in the mobile IPTV service, the mobile set-top box STB, which performs a function similar to the set-top box STB shown in FIG. 1, may be implemented in a form embedded in a mobile terminal device capable of supporting the mobile IPTV service.

FIG. 2 is a diagram illustrating a structure of a network adaptation layer (NAL) unit in video content encoded in H.264 / AVC format among digital video contents.

As shown in FIG. 2, one NAL unit 21 includes a NAL header 22 indicating a type of the NAL unit, and RBSP (data corresponding to compressed video data or header information). Raw Byte Sequence Payload) 23, and such NAL units exist continuously.

At this time, the present invention for achieving the above object uses information of NAL units having different types. Information about each type of NAL unit is shown in the following [Table 1]. In the present invention, a lightweight H.264 / AVC video content encryption method is realized using a type of NAL unit defined in Table 1 below.

In Table 1, the type of the NAL unit can be confirmed, and only 1 to 12 are defined so far. The NAL unit thus defined may have compressed video data or may have data for header information. In other words, some of the NAL unit types in Table 1 above are header information of other NAL unit types. Among the NAL unit types, representative types of header information of other NAL unit types are SPS (Sequence Parameter Sets) and PPS (Picture Parameter Sets).

Here, the SPS is header information including information covering the entire encoding of the sequence such as the profile and the level, and includes a profile ID, a level, a number of reference frames, and a screen size ( Resolution).

The PPS is important header information applied to various pictures in a video sequence and includes information such as entropy encoding mode, the number of slice groups, and a weight prediction method of the entire picture.

FIG. 3 is a diagram illustrating NAL bit strings in video content encoded in H.264 / AVC format among digital video contents in NAL unit type.

3 illustrates a case in which the type of each NAL unit in the video content encoded in the H.264 / AVC format is a type of SPS-PPS-PICTURE-PICTURE-SPS-PPS-PICTURE-PPS-PICTURE. Here, for example, if the type of one NAL unit 21 shown in FIG. 2 is an SPS, this may be represented as "SPS" in 31 of FIG. 3.

On the other hand, the lightweight video content encryption method of the present invention, in encrypting the H.264 / AVC video content, services the content requested to be transmitted from the service user in the form of streaming, but does not encrypt the entire content Encryption is only performed on some elements of the digital video content.

In this case, some elements of the digital video content to be encrypted are some elements of the transmission bitstream encoded by the above-described H.264 video codec, and among the types of NAL units included in the bitstream, "decode digital video content". Information that is essential for reproducing on the screen, ”and finally encrypts only the type that becomes“ essential information for decoding and reproducing digital video content on the screen ”.

More specifically, in the present invention, among the types of NAL units included in the bitstream, the SPS or PPS is extracted and encrypted as " essential information for decoding and playing the digital video content on the screen. &Quot; Here, the SPS and the PPS are pieces of information necessary for decoding digital video contents and playing them on the screen.

FIG. 4 is an exemplary explanatory diagram of a lightweight video content encryption method for providing a mobile content service according to the present invention, showing how to partially encrypt digital video content.

In the present invention, only the type of information necessary for decoding and playing digital video contents is encrypted, but only the RBSP portion is selectively encrypted except for the NAL header portion constituting the NAL unit so that the digital video contents can be reproduced. .

That is, as shown in FIG. 4, in one embodiment of the present invention, only the RBSP portion of the SPS, which is information necessary for decoding and playing digital video content, selectively performs encryption.

Further, another embodiment of the present invention selectively encrypts only the RBSP portion of the PPS, which is information necessary for decoding and playing digital video content.

Meanwhile, when performing encryption on the NAL unit, encryption is performed using AES (Advanced Encryption Standard), but encryption is performed in units of 128 bits (16 bytes). That is, the encryption is performed using a general AES-128 with a key size of 128 bits. Encryption and decryption are performed using such an encryption key. When providing a streaming service, digital video content is divided into 128-bit blocks and transmitted after being encrypted. In addition, during decryption, the mobile terminal apparatus (which is equipped with a set-top box) on the service user side receives the bitstreams by 128 bits and performs decryption.

FIG. 5 is a structural diagram of a general IPTV communication model (IPTVCM), and shows a hierarchical network framework composed of seven (and one optional) concept layers.

As shown in FIG. 5, video data is transferred from the top layer to the next lower layer along the IPTVCM in a sending IPTV device, and is received through a broadband network by a physical layer protocol. Is sent to. Accordingly, the video data arrives at the physical layer of the IPTVCM in the Receiving IPTV device and is passed from the lowest layer to the next higher layer along the IPTVCM to the higher layer.

As shown in FIG. 5, in IPTVCM, which consists of all seven (and one optional) concept layers, the encryption process is performed between the video encoding layer, which is the uppermost layer, and the video packetization layer, which is lower. When encoding is performed in the video encoding layer, VCL data, which is video data, is mapped to NAL data for transmission in a stream. The video stream is then encrypted and transmitted after being encrypted.

FIG. 6A is a flowchart illustrating a lightweight video content encryption method for providing a mobile content service according to the present invention. FIG. 6A is a H.264 / AVC diagram of a sending IPTV device, that is, a content server. In order to transmit digital video content, only the RBSP portion of the SPS, which is essential information for decoding and playing digital video content, is shown.

Here, FIG. 6A shows a process in a state where it is assumed that the service user has already been authenticated by the service provider as a legitimate user. This is also the same in FIGS. 6B, 7A and 7B.

Referring to FIG. 6A, the video content encryption process starts when a content server is requested to transmit video content from a mobile terminal device of a service user (601).

Thereafter, the content server generates an encryption key for performing encryption using an encryption key generator embedded therein (602).

Thereafter, the content server transmits the generated encryption key to the license server, and the license server stores the generated encryption key (603).

Thereafter, the content server starts transmitting the video content requested from the mobile terminal device of the service user to the corresponding mobile terminal device (604).

In this case, the content server detects a stream of which the NAL unit type is an SPS among streams of the transmitted digital video content (605).

In this case, when a stream having a SPS type of NAL unit is detected, the content server encrypts only RBSP of the detected stream (NAL unit) using the generated encryption key (606). That is, only the RBSP portion of the SPS, which is essential information for decoding and playing digital video content, is encrypted using the generated encryption key. After performing the encryption process 606, a packet is generated (607). If a stream whose type of NAL unit is SPS is not detected, a packet is immediately generated (607).

Thereafter, the content server transmits the generated packet to the mobile terminal device at the service user side (608). The process is repeated from the SPS detection process 605 until the end of the transmitted stream, that is, until the end of stream (EOS) is reached.

FIG. 6B is a flowchart illustrating a lightweight video content decoding method for providing a mobile content service according to an embodiment of the present invention, and is received from a content server at a receiving IPTV device side, that is, a mobile terminal device of FIG. 5. A process of selectively decrypting only the RBSP portion of the SPS among the encrypted digital video contents is shown.

Referring to FIG. 6B, first, a mobile terminal device (which is equipped with a mobile set-top box) requests digital video content to be viewed by a content server of a service provider (611).

After the mobile terminal device requests the video content, the mobile terminal device downloads the encryption key (see FIG. 6A), which is previously generated by the content server of the service provider and transmitted to the license server, from the license server (612).

Thereafter, the mobile terminal device starts to download digital video content transmitted from the content server of the service provider and receives a packet (613).

In this case, the mobile terminal device streams the downloaded packet, that is, unpackets the downloaded packet to generate a stream (614) and detects a stream whose type of NAL unit is SPS among the streams of the streamed digital video content. (615).

In this case, when a NAL unit type of the SPS is detected, the mobile terminal device decodes only the RBSP of the detected stream (NAL unit) using the downloaded encryption key (616) and then uses the corresponding stream of video content. (617), if the stream of which the type of the NAL unit is SPS is not detected, immediately plays the video content using the stream (617).

The process is repeated from the SPS detection process 615 until the end of the stream being received, that is, until the end of stream (EOS) is reached.

Meanwhile, as another embodiment of the present invention, a method for selectively encrypting and decrypting only the RBSP portion of the PPS, which is information essential for decoding and playing digital video content, is the encryption and decryption method shown in FIGS. 6A and 6B. Since the procedure is the same except that only the encryption and decryption targets are different, the description will not be repeated herein any further.

7A and 7B are graphs illustrating results of execution time when encryption and decryption is performed on H.264 / AVC video content having 300 frames and a resolution of 176 × 144.

Here, FIG. 7A illustrates a case where an execution time when partially encrypting digital video content by selecting only an SPS is compared with an execution time when encrypting digital video content as a whole, and FIG. 7B partially decrypts by selecting only an SPS. The case where the time of performing the decoding and the time of decoding the overall content are compared. In this case, the encryption and decryption process is performed 15 times each, and the number on the right of each graph is the average of each execution time.

As shown in FIG. 7A and FIG. 7B, it can be seen that the average execution time is greatly reduced when partial encryption and decryption are performed by selecting only the SPS as compared to the existing overall encryption and decryption. That is, in the present invention, due to partial encryption, the average execution time may be reduced, and thus overhead may be reduced.

Meanwhile, the lightweight video content encryption and decryption method for providing a mobile content service according to the present invention as described above may be implemented in the form of program instructions that can be executed by various computer means and recorded in a computer readable medium. . The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on the media may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks, such as floppy disks. Magneto-optical media, and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. The medium may be a transmission medium such as an optical or metal line, a wave guide, or the like, including a carrier wave for transmitting a signal designating a program command, a data structure, or the like. Examples of program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like. The hardware device may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, Various permutations, modifications and variations are possible without departing from the spirit of the invention.

Therefore, the scope of the present invention should not be construed as being limited to the embodiments described, but should be determined by the scope of the appended claims, as well as the appended claims.

The present invention can protect the rights of service providers and content producers by applying the encryption and decryption of the content by applying to the DRM (Digital Rights Management), CAS (Conditional Access System), etc. In particular, it can be used as an IPTV service, i.e., a mobile IPTV service, through a mobile terminal having limited resources as lightweight encryption.

11, 12: Contents Server
13, 14: License Server
15, 16: Set-Top Box (STB)

Claims (12)

In the video content encryption method,
Receiving a request for transmission of video content;
Generating an encryption key for performing encryption using an encryption key generator;
Detecting a stream having a type of Network Adaptation Layer (NAL) unit of Sequence Parameter Sets (SPS) among streams of the video content while transmitting the requested video content; And
Encrypting a raw byte sequence payload (RBSP) of the detected stream using the generated encryption key;
Video content encryption method comprising a.
The method of claim 1,
The encryption step,
Generating a packet and transmitting the packet to the mobile terminal device if the stream of which the type of the NAL unit is SPS is not detected; And
If a stream having a type of NAL unit SPS is detected, encrypting the RBSP of the SPS using the generated encryption key, and then generating a packet and transmitting the packet to the mobile terminal device.
Video content encryption method comprising a.
In the video content decoding method,
Requesting video content;
Downloading an encryption key to be used to decrypt the video content;
Detecting a stream having a type of Network Adaptation Layer (NAL) unit of Sequence Parameter Sets (SPS) from among streams of the video content while downloading and streaming the requested video content; And
Decryption step of decrypting a raw byte sequence payload (RBSP) of the SPS of the detected stream by using the downloaded encryption key
Video content decoding method comprising a.
The method of claim 3, wherein
The decoding step,
If the stream whose type of NAL unit is SPS is not detected, playing the video content; And
If a stream having a NAL unit type SPS is detected, decoding the RBSP of the SPS using the downloaded encryption key and then playing the video content.
Video content decoding method comprising a.
In the video content encryption method,
Receiving a request for transmission of video content;
Generating an encryption key for performing encryption using an encryption key generator;
Detecting a stream having a type of Network Adaptation Layer (NAL) unit of Picture Parameter Sets (PPS) among streams of the video content while transmitting the requested video content; And
Encrypting a raw byte sequence payload (RBSP) of the PPS from the detected stream using the generated encryption key
Video content encryption method comprising a.
The method of claim 5, wherein
The encryption step,
If a stream whose type of NAL unit is PPS is not detected, generating a packet and transmitting the packet to the mobile terminal device; And
If a stream having a NAL unit type PPS is detected, encrypting the RBSP of the PPS using the generated encryption key, and then generating a packet and transmitting the packet to the mobile terminal device.
Video content encryption method comprising a.
In the video content decoding method,
Requesting video content;
Downloading an encryption key to be used to decrypt the video content;
Detecting a stream having a type of Network Adaptation Layer (NAL) unit of Picture Parameter Sets (PPS) from among streams of the video content while downloading and streaming the requested video content; And
Decryption step of decrypting a raw byte sequence payload (RBSP) of the PPS of the detected stream using the downloaded encryption key
Video content decoding method comprising a.
The method of claim 7, wherein
The decoding step,
If the stream whose type of NAL unit is PPS is not detected, playing the video content; And
If a stream having a type of NAL unit PPS is detected, decoding the RBSP of the PPS using the downloaded encryption key and then playing the video content.
Video content decoding method comprising a.
On the content server,
Receiving a request for transmission of video content;
Generating an encryption key for performing encryption using an encryption key generator;
Detecting a stream having a type of Network Adaptation Layer (NAL) unit of Sequence Parameter Sets (SPS) among streams of the video content while transmitting the requested video content; And
Encrypting a raw byte sequence payload (RBSP) of the detected stream using the generated encryption key;
A computer-readable recording medium having recorded thereon a program for realizing this.
In a terminal device having a processor,
Requesting video content;
Downloading an encryption key to be used to decrypt the video content;
Detecting a stream having a type of Network Adaptation Layer (NAL) unit of Sequence Parameter Sets (SPS) from among streams of the video content while downloading and streaming the requested video content; And
Decryption step of decrypting a raw byte sequence payload (RBSP) of the SPS of the detected stream by using the downloaded encryption key
A computer-readable recording medium having recorded thereon a program for realizing this.
On the content server,
Receiving a request for transmission of video content;
Generating an encryption key for performing encryption using an encryption key generator;
Detecting a stream having a type of Network Adaptation Layer (NAL) unit of Picture Parameter Sets (PPS) among streams of the video content while transmitting the requested video content; And
Encrypting a raw byte sequence payload (RBSP) of the PPS from the detected stream using the generated encryption key
A computer-readable recording medium having recorded thereon a program for realizing this.
In a terminal device having a processor,
Requesting video content;
Downloading an encryption key to be used to decrypt the video content;
Detecting a stream having a type of Network Adaptation Layer (NAL) unit of Picture Parameter Sets (PPS) from among streams of the video content while downloading and streaming the requested video content; And
Decryption step of decrypting a raw byte sequence payload (RBSP) of the PPS of the detected stream using the downloaded encryption key
A computer-readable recording medium having recorded thereon a program for realizing this.

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