KR20110064487A - Method and apparatus for providing data freshness check of media data - Google Patents

Abstract

PURPOSE: A method and apparatus for providing data freshness check of media data are provided to configure an SVC(Scalable Video Coding) and conversion information as a message digest with a feature and control information by layer. CONSTITUTION: A scalable media transmitter(100) transmits feature information and control information which are extracted from the encoded and converted scalable media data. A scalable media receiver(300) verifies the integrity of the scalable media. A secure directory(400) stores the characteristic information and control information. A scalable media reuse device(500) requests the retransmission of the scalable media to the scalable media receiver.

Description

METHOD AND APPARATUS FOR PROVIDING DATA FRESHNESS CHECK OF MEDIA DATA}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for more robustly providing the freshness of multimedia image data, particularly scalable media data encoded with the scalable video coding (SVC) video compression standard. The present invention relates to a method and apparatus for verifying integrity of media data suitable for extracting feature information and using one-way accumulator to guarantee the currentness and reuse of data from an integrity point of view.

The present invention is derived from the research conducted as part of the IT growth engine technology development project of the Ministry of Knowledge Economy [2008-S-006-02, Development of open IPTV (IPTV2.0) technology in wired and wireless environments].

Scalable Video Coding (SVC) is an extended video compression standard of the ITU-T H.264 / AVC standard that allows video encoded using these SVCs to be encoded in one base layer and It may be configured with a plurality of enhancement layers.

The base layer is the most essential for video playback, but provides the lowest video quality and can be decoded independently. On the other hand, enhancement layers increase the image quality of the base layer in terms of resolution, frame rate, quality, and the like, and independent decoding is impossible.

The advantage of this multi-layer structure is that, through one encoding operation, the media structure can be dynamically rearranged to meet service requirements. Specifically, three types of scalability, for example, space, time, and SNR (signal to noise ratio), are selected based on the performance of a specific receiving terminal, bandwidth of a transmission network, and a subscription level of a video streaming service. Can be dynamically configured and provided, because it is possible to downgrade the image quality by discarding some of the enhancement layers through the SVC extractor.

Such technical characteristics can be expected to have a big ripple effect in the recent multimedia market for OSMU (One Source Multi Use) characteristics.

On the other hand, the data integrity (data integrity) means to ensure that the received data provided to the terminal is securely transmitted without any illegal intervention and modification during transmission. Integrity can be implicitly verified through data encryption, or secured through Message Authentication Code or Keyed cryptographic hash function (MAC), and it is also keyless hash functions, Message Digest algorithm 5 (MD5) and SHA1 (Secure). Hash Algorithm 1) and the like.

However, the above-mentioned conventional integrity checking method has a strong tendency that its target is limited to static data, and scalable media has dynamic variability which is converted according to user or service requirements, so that continuous guarantee of data integrity is very high. It is true that it is difficult. In addition, the path of media distribution has recently diversified, such as a scalable media redistribution chain, and the problem of retransmission has been highlighted.

Therefore, it is reality and not appropriate to simply ensure robust integrity enough to simply check whether the received data matches the original data.

Therefore, in order to ensure the safe distribution and reuse of SVC scalable media data, it is necessary to devise a technique that can extend and apply the conventional data integrity concept. Moreover, in recent years, subjects using media distributed through illegal conversion processes are also creating social and legal conditions that cannot be avoided.

The present invention contemplates such a conventional situation, and uses integrity verification technology for scalable video streaming service, IPTV or similar content service to ensure legal usage tracking and reuse of media data. I want to have the skills to do it.

In addition, by verifying and assuring the data integrity of scalable media, the technology to increase the possibility of complex sharing and reuse of data and to increase the reliability of the quality of the data itself.

According to the method for verifying the integrity of media data to solve the problems of the present invention, when the transmission of the scalable media from the media receiver is requested to perform the step of encoding and restructuring the scalable media to generate the media data for each layer, After the feature information and control information is extracted from the layer-specific media data, calculating the layer-specific integrity information for the layer-specific media data, the layer-specific media data, the characteristic information and control information, the layer-specific integrity information And transmitting to the media receiver.

The calculating of the integrity information may include: hashing the extracted characteristic information and control information; storing a hash value generated by the hashing process for each media layer; And calculating the integrity information for each layer using a one-way accumulation hash function.

The integrity verification method may further include encrypting the control information using an Advanced Encryption Standard (AES) encryption algorithm and packaging the control information to be encrypted.

The integrity verification method may further include calculating final scalable media integrity information by using the one-way accumulating hash function, the media data for each layer, the characteristic information and control information, the integrity information for each layer, and the final information. The method may further include a step of configuring scalable media integrity information as one data set and binding the scalable media integrity information to a protocol of an internet based network.

According to the method of verifying the integrity of media data for solving the problems of the present invention, the process of receiving the media data including media characteristic information, control information and integrity information from the media transmitter via a network, and the characteristic information and The process of extracting control information to calculate the integrity of each layer, comparing the calculated layered integrity with a predetermined layered integrity and verifying the presence of the media data, and the process of verifying the presence of the media data If it fails, the method may include requesting the media transmitter to search for and retransmit the same media data.

Here, the characteristic information may be scalable media data for each layer and integrity information for each layer.

The integrity verification method may include: verifying reuse stability of the integrity if the currentity verification process for the media data is successful; and decoding or storing the media data if the verification of the reuse stability is successful. It may further include.

In addition, the process of verifying the reuse stability may include calculating a integrity information on the media data by performing a one-way accumulation hash function using the integrity information of each layer of the media data, and receiving the calculated integrity information and previously received information. Comparing the integrity information, and if the calculated integrity information and the previously received integrity information may include the step of determining that the verification of the reuse stability is successful.

In addition, the previously received integrity information may be databased in a secure directory.

In addition, the network may be an IP-based wired or wireless network.

The media data may be scalable media data.

According to an apparatus for verifying integrity of media data for solving the problems of the present invention, a scalable media transmitter for transmitting encoded and converted scalable media data and characteristic information and control information extracted from the scalable media data through a network A scalable media receiver configured to receive scalable media from the scalable media transmitter to verify freshness, decode and store the scalable media, and then retransmit, and store the characteristic information and control information; A secure directory that supports key generation, key exchange, and key revocation between the sender and the receiver; and a scalable media reuse device for requesting retransmission of the scalable media to the scalable media receiver and using the retransmitted scalable media. Can be.

Here, the scalable media transmitter is configured to convert the scalable media according to the scalable video compression standard, the scalable media encoded through the media encoder, and transmit the converted scalable media. And a feature extractor for extracting the feature information and the control information and processing the extracted feature information and the control information.

The media extractor may convert the video structure by removing the enhancement layer of the scalable media encoded by the media encoder according to terminal performance or service requirements.

In addition, the media extractor may transmit the scalable media through packetizing and protocol binding.

The network may be an IP-based wired or wireless network, and may provide an environment in which the scalable media receiver can be connected to the scalable media transmitter and the secure directory.

The secure directory may store a hash value by extracting the characteristic information and the control information in a database, and the scalable media receiver may transmit the characteristic information and the control information of a specific layer using a communication channel when requested. .

In addition, the secure directory may be utilized as a support medium based on a public key infrastructure.

In addition, the processing may include hash and encryption.

The scalable media receiving unit may further include: an integrity verifying unit configured to receive the scalable media, the characteristic information, and the control information, and verify the integrity in terms of current and reuse of the scalable media; A media decoder which decodes the scalable scalable media through the integrity verification unit to enable playback of an image, converts media data to be retransmitted, updates the characteristic information and control information, and updates the media data and the characteristic. It may include a retransmission unit for retransmitting information and control information.

According to the present invention, by providing a message digest with information on the generation and conversion of scalable video coding (SVC) scalable media together with layer-specific characteristics and control information, it is possible to provide a function for verifying the presence of SVC scalable media. By performing a process of comparing and verifying the message digest with the original using a one-way accumulator, it is possible to verify whether the SVC scalable media can be safely reused, and thus the data can be dynamically It is robust and agile to change, while ensuring continuous integrity verification. As a result, by providing the two functions mentioned above, the data traceability of scalable media is considered in consideration of the usage environment, user requirements, distribution / use type diversification, and the continuity of data integrity. And, it can provide a function for authenticating that it is a safe workpiece to the reuse receiving terminal.

The present invention is a scalable video coding technology that supports dynamic characteristics that can transform the structure of media according to service requirements. The present invention provides a method of verifying the integrity of encoded media streaming data at a receiving terminal. Is a method and an apparatus for verifying that there is no exposure from illegal access from two perspectives, current and reusable. However, the integrity in the present invention is to extend the existing concept of data integrity (data integrity) in terms of the current (currency) and reuse (reuse) of the data.

The present invention provides a method and apparatus for providing a function that guarantees both aspects of presentness and reuse, in order to provide continuous freshness guarantee of image data having a dynamic scalable feature encoded with the SVC video compression standard. It is about. In the present invention, the individual feature information is extracted from the SVC video layer, and the extracted layer information and additional control information such as content ID, user ID, number of conversions, initial creation time, and latest conversion time together are a one-way accumulated hash function (one-way). Use an accumulator to convert to a message digest. The hierarchical hashed property and control information thus obtained are verified by using a one-way accumulated hash function to verify data integrity between the scalable media sender and the receiver.

In the present invention, the concept of extension of existing data integrity is defined as "Freshness", and the meaning is largely divided into currentity and reuse. First, current assurance refers to the "Freshness" characteristic of the temporal concept such as when the data that is received when the receiving terminal requests the scalable media is first generated, when the conversion process is recently performed, and the total number of conversions. It means the technology to verify and guarantee this. Next, reuse assurance means that the receiving terminal that wants to reuse can check the safe reuse by ensuring that the data provided to the receiving terminal has no illegal modification or forgery during the intermediate delivery process. Means that. Specifically, a procedure for checking whether the received data has the same media characteristic information as the original is performed.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, and only the embodiments make the disclosure of the present invention complete, and the general knowledge in the art to which the present invention belongs. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. Like numbers refer to like elements throughout.

In describing the embodiments of the present invention, if it is determined that a detailed description of a known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, terms to be described below are terms defined in consideration of functions in the embodiments of the present invention, which may vary according to intentions or customs of users and operators. Therefore, the definition should be based on the contents throughout this specification.

Combinations of each block of the accompanying block diagram and each step of the flowchart may be performed by computer program instructions. These computer program instructions may be mounted on a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment such that instructions executed through the processor of the computer or other programmable data processing equipment may not be included in each block or flowchart of the block diagram. It will create means for performing the functions described in each step. These computer program instructions may be stored in a computer usable or computer readable memory that can be directed to a computer or other programmable data processing equipment to implement functionality in a particular manner, and thus the computer usable or computer readable memory. It is also possible for the instructions stored in to produce an article of manufacture containing instruction means for performing the functions described in each block or flow chart step of the block diagram. Computer program instructions may also be mounted on a computer or other programmable data processing equipment, such that a series of operating steps may be performed on the computer or other programmable data processing equipment to create a computer-implemented process to create a computer or other programmable data. Instructions that perform processing equipment may also provide steps for performing the functions described in each block of the block diagram and in each step of the flowchart.

In addition, each block or step may represent a portion of a module, segment or code that includes one or more executable instructions for executing a specified logical function (s). It should also be noted that in some alternative embodiments, the functions noted in the blocks or steps may occur out of order. For example, the two blocks or steps shown in succession may in fact be executed substantially concurrently or the blocks or steps may sometimes be performed in the reverse order, depending on the functionality involved.

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

First, FIG. 1 illustrates a structure of a scalable media generation and distribution service based on scalable video coding that can be applied to the present embodiment, and includes an SVC encoder 10, an SVC extractor 12, and a reception. Terminal group 14 and the like.

As illustrated in FIG. 1, the original video image 1 refers to raw data of a raw type before performing encoding of the SVC standard. In FIG. 1, each frame when an image is played will be exemplified for better understanding.

The SVC encoder 10 encodes the original video image 1 according to the SVC video compression standard to generate an initial media hierarchy. The initial media hierarchy 2 illustrates the hierarchical structure of the SVC scalable image, for example, one base layer (B-Layer 1) and two enhancement layers (E-Layer 2, E-Layer 3). An encoded video composed of a total of three layers may be considered.

The SVC extractor 12 performs a function of extracting an unnecessary enhancement layer in order to variably transform the initial hierarchical structure 2 of the scalable media according to the terminal performance and service requirements. In FIG. 1, reference numeral 3 exemplifies a converted media hierarchy 3 extracted by the SVC extractor 12, and reference numeral 4 denotes a converted media image representing the converted media hierarchy 3 in terms of image reproduction. It is an example.

Receiving terminal group 14 is a user terminal group for receiving the above-described conversion media image, in the present embodiment according to the performance, such as the screen size, playback speed, network bandwidth of the terminal 'high, medium (medium) ), Low ', and the like.

Next, a scalable media redistribution chain can be illustrated as in FIG. 2 and can be extended to more complex structures.

First, the scalable media original transmission terminal 20 refers to the first original sender that configures / generates and distributes the scalable media.

The first retransmission terminal 22 receives and uses the original data or the converted data from the scalable media original transmission terminal 20 and performs a first retransmission.

The second retransmission terminal 24 receives and uses the original data or the converted data from the first retransmission terminal 22 and performs a second retransmission.

FIG. 3 is a module-based system that comprises a series of processes proposed in this embodiment, such as extracting, transmitting, transforming, and verifying integrity information, from media characteristics and control information from a scalable media sender and receiver perspective. A media transmitter 100, a network 200, a scalable media receiver 300, a secure directory 400, a scalable media reuse device 500, and the like. It may include.

As illustrated in FIG. 3, the scalable media transmitter 100 encodes and converts scalable media, extracts characteristics and control information of the encoded scalable media, and controls the characteristics and control of the extracted scalable media. The function of transmitting information can be performed.

The scalable media transmitter 100 may include a media encoder 102, a media extractor 104, a feature extractor 106, and the like, and each configuration thereof will be described below.

First, the media encoder 102 may play a role of encoding original video data, that is, scalable media according to the SVC video compression standard.

The media extractor 104 converts the video structure by removing the enhancement layer from the scalable media encoded through the media encoder 102 according to terminal performance or service requirements, and transmits the converted media (eg, packeta). Packetizing, protocol binding, etc.).

The feature extractor 106 extracts hierarchical characteristics and control information of the scalable media required for freshness verification and performs processing (eg, hash, encryption, etc.) according to the present embodiment. can do.

On the other hand, the network 200 is, for example, an IP (Internet Protocol) based wired or wireless network (Internet), and means an open computer network structure that provides various services existing in the TCP / IP protocol and its upper layer, and scale The flexible media receiver 300 provides an environment in which the scalable media transmitter 100 and the secure directory 400 can be connected.

The scalable media receiver 300 may receive the scalable media to verify freshness-related information, decode and store the information, and retransmit the information.

The scalable media receiver 300 may include a freshness verifier 302, a media decoder 304, a redistributor 306, and the like. Let's look at the following.

First, the integrity verification unit 302 may receive a scalable media, characteristics of each layer, control information, and the like, and verify integrity in terms of current and reuse of the media.

The media decoder 304 decodes the scalable scalable media through the integrity verifier 302 to enable image playback.

The retransmission unit 306 converts scalable media when there is a retransmission request, updates time, characteristics, and control information, and is responsible for data transmission.

On the other hand, the secure directory 400 extracts the hierarchical characteristics and control information of the scalable media from the feature extractor 106 described above and safely stores the hashed values in the database 402. When the media receiving unit 300 requests the characteristic and control information of a specific layer, the media receiving unit 300 transmits the information using a secure communication channel (for example, Secure Sockets Layer (SSL)). Public Key Infrastructure)) can be used as a medium for key generation, key exchange, and key revocation between sender and receiver.

The scalable media reuse device 500 refers to a reuse terminal that requests retransmission of the scalable media from the primary receiving terminal and uses the same. In FIG. 3, one scalable media reuse device is illustrated for convenience of understanding. Those skilled in the art will readily appreciate that a plurality of reusable devices applied to the present embodiment may be configured.

In addition, in the present embodiment, in the case of a terminal in charge of consumption and retransmission of scalable media at the same time, all of the above-described internal modules of the scalable media transmitter 100 and the scalable media receiver 300 are integrated into one system. It should be noted that this may be the case.

Hereinafter, with reference to the configuration described above, with reference to Figures 4 to 6 attached to the integrity verification method of the media data according to an embodiment of the present invention will be described in detail.

Additional Explanations and Assumptions

However, in the present invention, the first scalable media provider is assumed to be a reliable entity that legally creates, encodes, and distributes media.

In addition, it is assumed that the secure directory is also considered as a secure entity with security, and is used as a secure medium for exchanging public keys between the sender and the receiver. Assume

In FIG. 3, the functions performed by the video streaming server and the client are considered to be operated according to a conventional video streaming system.

FIG. 4 illustrates a process of extracting characteristic information for each layer from the scalable media and hashing it together with hierarchical control information, encrypting the control information, and configuring the integrity of the entire media.

Extraction of hierarchical characteristic information (400): In the SVC video compression standard, when pixel values are orthogonally transformed into frequency components through DCT (Discrete Cosine Transform), the frequency values are AC (AC component) and DC (DC component). In this case, a component exceeding a specific threshold α among DC components is represented as 1 otherwise 0, and the media characteristic information f _i of the i layer is extracted by listing them in binary data form. Formula. Here, f _i is the media feature information extracted from the i-th layer, DC (Discrete Coefficients) is a DC component constituting a macroblock of the SVC media, α is a threshold value for extracting feature information for each layer ( thresholds respectively.

Additional Explanations and Assumptions

Characteristic information extraction for each layer of scalable media is flexible to reduce overhead due to feature information extraction, such as targeting only DC information belonging to a specific GOP (Group of Picture) if not all DC information can be targeted. Can be operated.

Hierarchical Expression 410: In the SVC video compression standard, media layers are classified according to spatial, temporal, and quality, and the present invention is simply expressed in decimal s. In this case, S denotes a spatial resolution, T denotes a frame rate per second, and Q denotes an SNR quality (Signal-to-Noise Ratio) or bit rate.

Characteristic and Control Information Hash Formulas for Each Layer (420, 430, 440): User ID (uid), SVC Video Content ID (cid), Initial Creation Date (crt _i ), and Latest Conversion Time (ext) for Each Layer of Scalable Media _i ) and the total number of transformations (exn _i ) and encrypt it with a symmetric key (sk _i ) given for each layer through LEX, a lightweight encryption algorithm version of the Advanced Encryption Standard (AES), and extracts the layer characteristic information (400). ) Is a formula representing a process of constructing a message digest by concatenating the media characteristic information f _i extracted for each layer in series with the media hierarchy s and then hashing it. The meanings of the elements in these equations are as follows.

LF _i : Integrity information of the i th layer of SVC scalable media (ith Layer Freshness)

LF _{i +1} : Integrity information of SVC scalable media i + 1 layer (i + 1th Layer Freshness)

LF _{i +2} : Integrity information of SVC scalable media i + 2 layer (i + 2th Layer Freshness)

H: Unkeyed Hash Function: MD5 or SHA1

LEX: Lightweight version of AES encryption encryption algorithm (L E X), used to encrypt freshness-related control information

sk _i : A symmetric key used to encrypt freshness-related control information of the i th layer of SVC scalable media.

uid: User Identity of SVC Scalable Media

cid: Identifier of SVC scalable media (Content Identity)

crt _i : Initial creation time of the i th layer of SVC scalable media (Create Time)

ext _i : Recent Conversion Time of layer i of SVC Scalable Media (Extraction Time)

exn _i : Total number of conversions of the i th layer of SVC scalable media (Extraction Number)

Additional Explanations and Assumptions

The layer-specific control information (uid, cid, crt _i , ext _i , exn _i ) can be reduced or expanded for the efficiency of system operation.

Control information encryption equation 450: AES and receiving terminal by the layer-specific control information (uid, cid, crt _i , ext _i , exn _i ) extracted from the above-described layer characteristics and control information hash equation (420, 430, 440) Each control is encrypted with a public key of pub _x . Here, AES (Advanced Encryption Standard) is an encryption algorithm used to encrypt freshness-related control information, and pub _x denotes a public key of the freshness-related control information receiver x.

SVC Scalable Media Characteristic Information Unidirectional Accumulated Hash Equation 450: This equation shows the mathematical characteristics of the unidirectional accumulating hash function H '. That is, there is a characteristic that the same value is calculated regardless of the order of the elements to be hashed. By using such a characteristic, the hierarchical media characteristic information hash values LF _i , LF _{i +1} , and LF _{i + 2} configured in the hierarchical characteristic and control information hash equations 320, 330, and 340 are obtained by using a unidirectional accumulator. Once again, the hash can finally obtain Media Freshness (MF) information. Here, MF means H 'one way accumulator for SVC scalable media integrity information.

Additional Explanations and Assumptions

Consider SVC scalable media consisting of a total of three layers (i, i + 1, i + 2).

It is assumed that the public key exchange and verification of the sender and the receiver are made through the security directory 400 of FIG. 3 described above according to a conventional public key infrastructure (PKI) technique.

FIG. 5 is a sequential diagram illustrating a process of transmitting scalable media and media integrity information to a receiver by a sender, and a process of verifying currentity of scalable media using the received integrity information.

The following describes the interaction and performance of each entity.

(S500): The scalable media receiver 300 requests the scalable media transmitter 100 for scalable media transmission.

In operation S510, the scalable media transmitter 100 generates media having a total of three layers by performing media encoding and structural conversion when necessary.

(S520): The scalable media transmitter 100 extracts and hashes the characteristics and control information for each media layer, transfers the hash value for each layer to the security directory 400, and media integrity for the entire scalable media layer. (MF = H '(H' (LF ₁ , LF ₃ ), LF ₂ )) is calculated using a one-way accumulated hash.

(S530): The secure directory 400 stores integrity information LF ₁ , LF ₂ , and LF ₃ for each media layer.

In operation S 540, the scalable media transmitter 100 transmits the scalable media, layer-specific integrity information, media integrity information, and encrypted control information, which are configured in two layers, to the scalable media receiver 300 after operation S 520.

(S550): The scalable media receiver 300 receives a data set (1 ^st layer, 2 ^nd Layer, LF ₁ , LF ₂ , Control Data, MF) transmitted from S540.

(S560): The control information is decrypted from the data set received in S550 by the private key of the scalable media receiver 300, and control information such as "uid, cid, crt, ext, exn" is extracted therefrom. do.

(S570): Characteristic and control information is extracted from each layer (1 ^st Layer, 2 ^nd Layer) of the received scalable media using Equation 400 of FIG. 4, and a layer integrity value LF ₁ using Equation 420. ', LF ₂ ').

S580: Compare LF ₁ ′, LF ₂ ′, and LF ₁ , LF ₂ to verify the currentity of each layer of the received scalable media, respectively.

(S590a): If the presentity verification fails, it is determined that scalable media that is not guaranteed to be present has been received.

(S590b): The scalable media receiver 300 requests the scalable media transmitter 100 to search for and transmit the latest data from the same media.

When these processes are completed and the currentness is guaranteed, a process of verifying the reuse stability of the integrity is performed. This process will be described in more detail below with reference to FIG. 6.

Additional Explanations and Assumptions

A general video content service request process in a video streaming environment is omitted.

In this embodiment, it is considered that only two layers of the three layers are transmitted.

It is assumed that all data is transmitted through a secure channel, and the media characteristic information formula configured in the transmitting device is assumed to be MF = H '(H' (LF ₁ , LF ₃ ), LF ₂ )). .

FIG. 6 is a sequential diagram illustrating a process of secure reuse assurance of scalable media after the recipient completes the integrity verification of integrity.

Hereinafter, the interaction and performance of each component will be described in detail with reference to FIG. 6.

(S600): Complete the presentness verification process of the scalable media mentioned in FIG.

S610: The scalable media receiving unit 300 requests the integrity information LF ₃ of the third layer to the secure directory 400.

(S620) (S630): The secure directory 400 performs a media search and returns integrity information LF ₃ of the third layer.

(S640): The scalable media receiving unit 300 receives this, and uses the integrity information LF1 ', LF2', and LF3 of each layer to generate a one-way accumulating hash of Equations 460 and MF '= H' (FIG. 4). H '(LF1', LF2 '), LF3))) to calculate the integrity information MF' for the entire media.

(S650): In order to verify the safety of data reuse, the received media integrity information MF is compared with the media integrity information MF 'obtained at S640 described above.

In operation S660, if MF and MF 'are the same and reuse validity is verified, the scalable media receiver 300 decodes or stores the scalable media.

(S670): After (S660), it is determined whether there is a retransmission request from the scalable media reuse device 500.

(S680): If there is a retransmission request, the scalable media receiver 300 may receive a retransmission request message and perform a related procedure for verifying the integrity of the reuse viewpoint mentioned in FIG. 6.

Additional Explanations and Assumptions

The media characteristic information formula configured in the receiving terminal may be expressed as MF '= H' (H '(LF ₁ ', LF ₂ ', LF ₃ )).

As described above, in the present embodiment, the generation and conversion-related information of the scalable video coding (SVC) scalable media is configured in a message digest form through characteristics and control information for each layer, so that the SVC scalable media It is possible to verify the existence of SVC scalable media by verifying the presence of the present message and verifying whether the message digest is compared with the original by using a one-way accumulator. It is designed to ensure continuous integrity verification while being robust and agile against dynamic changes in data.

1 and 2 are schematic diagrams illustrating scalable media generation / distribution and retransmission based on scalable video coding applied to the present embodiment;

3 is a block diagram of a data integrity verification system of a scalable media according to the present embodiment;

4 is a diagram illustrating an equation for extracting and verifying integrity information according to the present embodiment;

5 is a flowchart illustrating a method for verifying integrity in terms of currentity of scalable media data according to the present embodiment;

6 is a flowchart illustrating an integrity verification method in terms of reuse stability of scalable media data according to the present embodiment.

Claims (20)

A scalable media transmitter for transmitting encoded and converted scalable media data, characteristic information and control information extracted from the scalable media data through a network; A scalable media receiver configured to receive scalable media from the scalable media transmitter to verify freshness, decode and store the scalable media, and then retransmit the scalable media; A secure directory that stores the property information and control information and supports key generation, key exchange and key revocation between sender and receiver; Requesting retransmission of the scalable media to the scalable media receiver, and including a scalable media reuse device using the retransmitted scalable media; Device for verifying the integrity of media data. The method of claim 1, The scalable media transmitter, A media encoder for encoding the scalable media according to a scalable video compression standard; A media extractor for converting the scalable media encoded through the media encoder and transmitting the converted scalable media; A feature extractor for extracting the feature information and control information and processing the extracted feature information and control information; Device for verifying the integrity of media data. The method of claim 2, The media extractor converts the video structure by removing the enhancement layer from the scalable media encoded by the media encoder according to terminal performance or service requirements. Device for verifying the integrity of media data. The method of claim 2, The media extractor transmits the scalable media through packetizing and protocol binding. Device for verifying the integrity of media data. The method of claim 1, The network is an IP (Internet Protocol) based wired or wireless network, and provides an environment in which the scalable media receiver can be connected to the scalable media transmitter and the secure directory. Device for verifying the integrity of media data. The method of claim 1, The secure directory extracts and hashes the characteristic information and control information in a database, and the scalable media receiver transmits the characteristic information and control information of a specific layer using a communication channel when requested. Device for verifying the integrity of media data. The method of claim 1, The secure directory is used as a support medium based on a public key infrastructure. Device for verifying the integrity of media data. The method of claim 2, The processing includes hash and encryption Device for verifying the integrity of media data. The method of claim 1, The scalable media receiver, An integrity verifier that receives the scalable media, the characteristic information, and the control information, and verifies the integrity in terms of current and reuse of the scalable media; A media decoder which decodes the scalable scalable media through the integrity verification unit to enable video reproduction; And a retransmitter configured to convert retransmission request target media data, update the characteristic information and the control information, and retransmit the media data, the characteristic information, and the control information. Device for verifying the integrity of media data. Generating a media data for each layer by encoding and restructuring the scalable media when the scalable media is transmitted from a media receiver; Extracting feature information and control information from the layered media data and calculating layered integrity information on the layered media data; Transmitting the media data for each layer, the characteristic information and control information, and the integrity information for each layer to the media receiver. How to verify the integrity of media data. 11. The method of claim 10, The process of calculating the integrity information, Hashing the extracted characteristic information and control information; Storing the hash value generated by the hashing for each media layer; Calculating integrity information for each layer by using a one-way accumulating hash function for the layer-specific media data. How to verify the integrity of media data. 11. The method of claim 10, The integrity verification method, Encrypting the control information using an Advanced Encryption Standard (AES) encryption algorithm; Packaging the control information to be encrypted; How to verify the integrity of media data. The method of claim 11, The integrity verification method, Calculating final scalable media integrity information using the one-way accumulate hash function; The method may further include binding the media data for each layer, the characteristic information and the control information, the layer-specific integrity information, and the final scalable media integrity information into a single data set and binding the data to a protocol of an internet-based network. How to verify the integrity of media data. Receiving media data including characteristic information, information, and media integrity information from the media transmitter through a network; Calculating hierarchical integrity by extracting feature information and control information from the media data; Comparing the calculated layer integrity with a predetermined layer integrity to verify whether the media data is present; If the currentness verification process for the media data fails, requesting a search and retransmission of the same media data to the media transmitter. How to verify the integrity of media data. The method of claim 14, The characteristic information is scalable media data for each layer and integrity information for each layer. How to verify the integrity of media data. The method of claim 14, The integrity verification method, If the presentness verification process for the media data is successful, verifying the reuse stability of the integrity; If the verification process for the reuse stability is successful, further comprising the step of decoding or storing the media data How to verify the integrity of media data. The method of claim 16, The process of verifying the reuse stability, Calculating integrity information on the media data by performing a one-way accumulation hash function using the integrity information of each layer of the media data; Comparing the calculated integrity information with previously received integrity information; Determining that the verification of the reuse stability is successful when the calculated integrity information is identical to the previously received integrity information. How to verify the integrity of media data. The method of claim 17, The received integrity information is databased in a secure directory. How to verify the integrity of media data. The method of claim 14, The network is an IP-based wired or wireless network How to verify the integrity of media data. The method according to any one of claims 14 to 19, The media data is scalable media data. How to verify the integrity of media data.

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