KR20080013218A - High definition multimedia interfacing method for video on demand service - Google Patents

Abstract

A high definition multimedia interfacing method for a VOD(Video On Demand) service is provided to permit the use of audio and video signals according to the VOD service only to an authenticated user. After encryption of digital video and audio signals by an HDMI(High Definition Multimedia Interface) through a predetermined encryption key, coding according to HDMI and HDCP(High-Bandwidth Digital Content Protection) transmission algorithms is performed and then the coding result is transmitted to a HDMI receiver(S203). The HDMI receiver performs a decoding according to the HDCP and HDMI receiving algorithms related to the transmitted digital audio and video signals(S205). When it is discriminated that the decoded digital video and audio signals are produced by a VOD service, the decoded digital video and audio signals are decoded by a previously stored decryption key corresponding to the encryption key and outputs the decoded digital video and audio signals to the display device(S223).

Description

High Definition Multimedia Interfacing Method for Video on Demand Service

1 is a block diagram of a high-definition multimedia interface device according to an embodiment of the present invention, and

2 is a flowchart provided to explain a high definition multimedia interface method for an on-demand video service according to an embodiment of the present invention.

According to the present invention, in transmitting digital video and audio signals using a high definition multimedia interface (HDMI), only a user who is authenticated with a video and audio signal according to a Video On Demand (VOD) service is provided. A high definition multimedia interface method for on-demand video services is made available.

High Definition Multimedia Interface (HDMI) is a multimedia interface capable of transmitting uncompressed full digital audio / video. In addition, the high definition multimedia interface (HDMI) provides a security function that blocks illegal copying of multimedia contents.

High-definition multimedia interface (HDMI) adds digital audio information to the existing digital video transmission standard, and there is no deterioration in image quality or sound quality when transmitting video and audio signals. The security function of the high definition multimedia interface (HDMI) is performed by a high-bandwidth digital content protection (HDCP) algorithm.

However, since the existing high definition multimedia interface (HDMI) standard does not consider the VOD (Video On Demand) standard, there is no content protection function so that only the user who applied for the VOD service can view the corresponding content. The existing high-definition multimedia interface (HDMI) standard is not suitable for a VOD service for a particular user because in encoding and decoding using HDCP, all encoding information can be decoded with a single decryption key value at the receiver.

An object of the present invention, in transmitting digital video and audio signals using a High Definition Multimedia Interface (HDMI), a user authenticated video and audio signals according to a Video On Demand (VOD) service The present invention provides a high-definition multimedia interface method for video-on-demand service that only the user can use.

In order to achieve the above object, the high-definition multimedia interface method for video-on-demand service according to the present invention, HDMI (High Definition Multimedia Interface) transmitter after encrypting the digital video and audio signal with a predetermined encryption key, HDMI and HDCP (High- Bandwidth Digital Content Protection) performing coding according to a transmission algorithm and transmitting to the HDMI receiver, the HDMI receiver performing decoding according to the HDCP and HDMI reception algorithm on the transmitted digital video and audio signal, and the decoded If it is determined that the digital video and audio signals are caused by an on-demand video service, decoding the decoded digital video and audio signals using a decryption key previously stored corresponding to the encryption key and outputting the decoded digital video and audio signals to a display device. do.

Here, the previously stored decryption key is coded by the HDMI transmitter, the authentication key and the decryption key according to the HDCP transmission algorithm to transmit to the HDMI receiver and the HDMI receiver HDCP the transmitted authentication key and decryption key And after decoding and decoding according to the HDMI reception algorithm, performing a predetermined authentication process using the authentication key and storing the same in a predetermined storage medium.

In the storing, when the predetermined storage medium is an external memory card, the decryption key may be encoded again using a separate encoding key and stored.

Hereinafter, the present invention will be described in detail with reference to the drawings.

1 is a block diagram of a high-definition multimedia interface device according to an embodiment of the present invention.

The High Definition Multimedia Interface (HDMI) device (hereinafter, referred to as “HDMI”) device 100 of the present invention can interface with the entire uncompressed digital video and audio signal as it is, and high-bandwidth digital (HDCP). Provides security against unauthorized replication, including Content Protection.

Furthermore, the HDMI device 100 of the present invention provides a separate encryption algorithm so that only a user (or receiver) authenticated for a Video On Demand (VOD) service can receive and watch the corresponding content.

The HDMI device 100 includes an HDMI transmitter and at least one HDMI receiver. The HDMI transmitter and the HDMI receiver may be connected by a link scheme such as transition minimized differential signaling (TMDS) or low voltage differential signaling (LVDS). The TMDS link is for transmitting digital video and audio signals farther and transmitting higher band video and audio signals. The TMDS link is preferable to the LVDS method in terms of securing a transmission distance.

In the HDMI device 100 according to the embodiment of FIG. 1, an HDMI transmitter 110 and first to third HDMI receivers 130, 150, and 170 are connected to each other. 1 illustrates an example in which an HDMI transmitter 110 and first to third HDMI receivers 130, 150, and 170 are connected by a TMDS link. Therefore, each of the HDMI transmitter 110 and the first to third HDMI receivers 130, 150, and 170 must include a separate chipset for the TMDS link, and the illustration is omitted in FIG.

The following description based on FIG. 1 will be described with the HDMI receiver 130 on behalf of the first to third HDMI receivers 130, 150, and 170.

The HDMI transmitter 110 is configured to encrypt an authentication key, a decryption key, and a digital video and audio signal transmitted to the HDMI receiver 130, and the digital video and audio signal encrypted by the encryption unit 111. And an HDMI transmission processor 113 for generating an HDMI packet by applying an HDMI transmission algorithm and an HDCP transmission processor 115 for applying an HDCP transmission algorithm to a packet to which the HDMI transmission algorithm is applied. HDMI packets coded by the HDCP transmission algorithm are subjected to basic encryption.

The HDMI transmitter 110 transmits the authentication key and the decryption key, which are HDCP encrypted in the HDMI transmission packet, to the HDMI receiver 130. The transmission of the authentication key and the decryption key by the HDMI transmitter 110 is for an on-demand video service, for example, each time the transmitted content is changed.

After transmitting the authentication key and the decryption key, the HDMI transmitter 110 encrypts the digital video and audio signal according to the corresponding content with an encryption key corresponding to the transmitted decryption key, and then performs signal processing according to the HDMI algorithm and the HDCP algorithm. After that, it transmits to the first to third HDMI receivers 130, 150, and 170 according to the TMDS link scheme.

The HDMI receiver 130 is connected to a display device (not shown) that displays a digital video signal and outputs an audio signal, and displays a digital video and audio signal received from the HDMI transmitter 110 (not shown). To send.

The HDMI receiver 130 may include an HDCP reception processor 131 that performs HDCP decoding on a packet transmitted to the HDMI transmitter 110, an HDMI reception processor 133 that performs HDMI decoding on an HDCP decoded packet, and predetermined decoding. The decoder 135 decrypts using a key.

The HDCP receiving processor 131 receives the HDCP encrypted authentication key and the decryption key through the TMDS link and decrypts them. In addition, the authentication key and the decryption key are HDMI-decoded by the HDMI receiving processor 133 and transmitted to the decryption unit 135, and the decryption unit 135 passes the decryption key transmitted after a separate authentication process using the authentication key. Save to internal memory or an external memory card. The authentication process is a process of confirming that the user of the HDMI receiver 130 is a user of an on-demand video service of the corresponding digital content. When storing the key in the external memory, the HDMI receiver 130 may repeat the separate encoding process again to block the use of the other HDMI receiver 130.

The HDMI receiver 130 decodes the HDMI packet transmitted from the HDMI transmitter 110 into a video signal and an audio signal. If the transmitted signal corresponds to an on-demand video service, the decoder 135 decodes the decoded video and audio signals with a decryption key previously received and stored, and transmits the decoded video and audio signals to an external display device (not shown). If the transmitted signal does not correspond to the video on demand service, the decoded video and audio signals are transmitted to an external display device (not shown).

When an illegal user who has not obtained the decryption key randomly attempts to use the on-demand video service, HDMI reception is normally performed, but the encrypted video and audio data cannot be decrypted, and thus, normal video and audio output cannot be viewed.

In addition, the HDMI transmitter 110 may determine whether the video and audio signals received from the front end are for an on-demand video service and skip or perform the encryption process. To this end, the HDMI receiver 130 should always transmit as HDMI packet information whether a signal to be transmitted is a private signal for an on-demand video service or the like.

2 is a flowchart provided to explain a high definition multimedia interface method for an on-demand video service according to an embodiment of the present invention.

The HDMI transmitter 113 and the HDCP transmitter 115 of the HDMI transmitter 110 first code an authentication key and a decryption key for an on-demand video service using HDMI and HDCP transmission algorithms, respectively, and transmit them to the HDMI receiver 130. (S201, S203).

When the HDCP receiving processor 131 of the HDMI receiver 130 receives the encrypted authentication key and the decryption key from the HDMI transmitter 110, the HDCP receiving processor 131 performs HDCP decoding and transmits the same to the HDMI receiving processor 133. The HDMI reception processor 133 performs HDMI decoding on the authentication key and the decryption key received from the HDCP reception processor 131 and transmits the HDMI key to the decryption unit 135 (S205).

The decryption unit 135 decrypts the received authentication key and decryption key with a second decryption key. The decryption unit 135 performs an authentication operation using the authentication key to confirm that the user is an authenticated user (S207), and then stores the decryption key in an internal memory or an external memory (S209).

The encryption unit 111 of the HDMI transmitter 110 encrypts digital video and audio signals to be transmitted to a plurality of HDMI receivers including the HDMI receiver 130 according to an on-demand video service with an encryption key corresponding to the decryption key transmitted in step S203. In operation S211, the HDMI transmission processor 113 and the HDCP transmission processor 115 code the encrypted video and audio signals (S213) and transmit the encoded video and audio signals to the HDMI receiver 130 (S215).

The HDCP receiving processor 131 and the HDMI receiving processor 133 of the HDMI receiver 130 decode the video and audio signals received from the HDMI transmitter 110 and transmit them to the decoder 135 (S217).

The decoder 135 determines whether the video and audio signals received from the HDMI reception processor 133 are based on the video on demand service (S219). The signal is decoded (S221).

The decoder 135 transmits the decoded video and audio signals to an external display device (not shown) (S223).

By the above method, the high-definition multimedia interface method for the video-on-demand service of the present invention is performed.

The invention can be implemented in methods, devices and systems. In addition, when the present invention is implemented in computer software, the components of the present invention may be replaced with code segments necessary for performing necessary operations. The program or code segment may be stored in a medium that can be processed by a microprocessor and transmitted as computer data coupled with carrier waves via a transmission medium or communication network.

The media that can be processed by the microprocessor include electronic circuits, semiconductor memory devices, ROMs, flash memory, electrically erasable programmable read-only memory (EEPROM), floppy disks, optical disks, and hard disks. (Hard) Includes the ability to transmit and store information such as disks, fiber optics, wireless networks, and the like. Computer data also includes data that can be transmitted over electrical network channels, optical fibers, electromagnetic fields, wireless networks, and the like.

In addition, although the preferred embodiment of the present invention has been shown and described above, the present invention is not limited to the above-described specific embodiment, the technical field to which the invention belongs without departing from the spirit of the invention claimed in the claims. Of course, various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

As described in detail above, the High Definition Multimedia Interface (HDMI) device according to the present invention encrypts video and audio signals according to a Video On Demand (VOD) service using a predetermined encryption key. By transmitting, only the authorized user can use the service.

Claims (3)

A high definition multimedia interface (HDMI) transmitter encrypting the digital video and audio signal with a predetermined encryption key, and performing coding according to the HDMI and High-Bandwidth Digital Content Protection (HDCP) transmission algorithm and transmitting the encoded video to an HDMI receiver; Performing decoding by the HDMI receiver according to an HDCP and HDMI reception algorithm on the transmitted digital video and audio signal; And When it is determined that the decoded digital video and audio signals are caused by an on-demand video service, the HDMI receiver decodes the decoded digital video and audio signals using a decryption key previously stored corresponding to the encryption key and outputs the decoded digital video and audio signals to a display device. High-definition multimedia interface method for an on-demand video service comprising a. The method of claim 1, The pre-stored decryption key, Transmitting, by the HDMI transmitter, the authentication key and the decryption key to the HDMI receiver by coding the authentication key and the decryption key according to an HDCP transmission algorithm; And Decoding, by the HDMI receiver, the transmitted authentication key and decryption key according to the HDCP and HDMI reception algorithms, and performing a predetermined authentication process using the authentication key and storing them in a predetermined storage medium; High-definition multimedia interface method for on-demand video services, characterized in that the stored. The method of claim 2, The storing step, And if the predetermined storage medium is an external memory card, re-encode the decryption key with a separate encoding key and store the encoded key.

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