KR20050045211A - Contents security system for host player, and method for the same - Google Patents

Abstract

The present invention can protect the copyright contained in the digital content file by preventing illegal copying of the digital content file provided from an external system in using the host player, which is a digital audio playback device having no built-in flash memory. It relates to a content security processing system. According to the present invention, in using a host player which is a digital audio playback apparatus that does not have a built-in flash memory, it is possible to effectively prevent illegal copying of a digital content file stored on a flash disk of a standard UMS standard. Even if the security device is hacked by performing version control and integrity check of the authentication data, it is possible to prevent the spread of the hacking damage by distributing a new version of the authentication data as soon as possible.

Description

Contents Security System For Host Player, And Method For The Same}

The present invention effectively protects the copyright contained in the digital content file by effectively preventing illegal copying of the digital content file provided from an external system in using the host player, which is a digital audio playback device having no built-in flash memory. And a content security processing system for a host player.

Conventionally, various types of digital audio playback devices such as flash memory built-in MP3 player, hard disk built-in MP3 player, or CDP type MP3 player have been used, and Next Way Co., which is a co-applicant of this patent application, registered a utility model in Korea. In the application 20-2002-0021305 and the unpublished Korean patent application No. 10-2003-0040147, a USB storage device according to the standard UMS standard without embedding a non-volatile space such as a flash disk or a hard disk, a so-called "flash disk" "I have presented the concept of a host player that can be used.

1 is a diagram conceptually showing an internal configuration of the host player 110 to which the content security processing system of the present invention is applied. The host player 110 supports a standard UMS standard and operates in a USB host mode, a USB interface 112, a control module 111 for controlling system operation, and a decoding module 113 for decoding digital audio data according to a specific standard. The control module 111 and the decoding module 113 are typically configured as a standard DSP and firmware. As described above, the host player 110 does not have a built-in nonvolatile space such as a flash memory or a hard disk for storing the digital audio file. Instead, the host player 110 receives the digital audio file from an external flash disk 130. .

That is, the conventional flash disk 130 includes a USB interface 132 that supports the standard UMS standard and operates in the USB device mode, and provides a flash memory 131 that provides a nonvolatile memory space for storing digital audio files. The host player 110 operates to read the stored digital audio file and decode it in the decoding module 113 by accessing the flash memory 131 through the USB interfaces 112 and 132. The internal structure of the illustrated host player 110 is merely conceptual and it should be understood that the actual host player 110 includes more components than those shown.

Since the digital audio file is assumed to use a normal flash disk 130 in the host player 110, illegal copying of the audio file is still unprotected. Accordingly, a content security processing system and method for using the host player 110 together with a conventional flash disk 130 according to a standard UMS standard, which can prevent illegal copying of digital audio files stored in the flash disk 130. This is desired.

Accordingly, the present invention protects the copyrights integrated in the digital content file by preventing illegal copying of the digital content file provided from an external system in using the host player, which is a digital audio playback device having no built-in flash memory. Its purpose is to provide a content security processing system for a host player.

In order to achieve the object of the present invention as described above, the present invention (1) a secure memory for storing a built-in certificate; A digital connection for coupling with an external device; Check whether there is a valid built-in certificate in the secure memory. ① If present, create a first certificate file based on the built-in certificate and record it in the external device. ② If not, an authentication request file of a specific format in the external device. 3) a security module for obtaining a decryption-key based on the embedded certificate; A decoding module for reproducing data of the digital content file read from the external device; And a decryption module for decrypting data of the digital content file using the decryption-key when the digital content file is encrypted. And (2) a UMS automatic detection module for automatically detecting that an external device is connected through a digital connection. Check whether there is a valid third certificate file in the external device. ① If present, obtain an encryption key based on the third certificate file. ② If not, based on an authentication request file of a specific format stored in the external device. An authentication data management module for generating a fourth certificate file, recording the same in the external device, and obtaining an encryption-key based on the fourth certificate file; And an administrator program having an encryption module for encrypting data of the digital content file using the encryption key.

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

2 is a diagram showing an embodiment of an internal configuration of a content security processing system according to the present invention.

The host player 210 according to the present invention has the same basic structure as the conventional host player 110 as described above with reference to FIG. 1, except that the system operation in the control module 211, in particular, the security processing of the digital content. It differs in operation and differs in that it includes a security module 212, a decryption module 214, and a secure memory 215 to assist in the security processing operation of the digital content. The security module 212, the decryption module 214, and the secure memory 215 may be selectively implemented as hardware and / or firmware, or a combination of both.

The secure memory 215 stores a built-in certificate for content security processing according to the present invention. The user cannot delete the stored content or read the data externally, and disassemble the device 210 to disassemble the memory module. It is desirable to be configured to prevent the decryption of the contents even if removed. The secure memory 215 may be set as a so-called bad block to physically prevent user deletion and external reading of the stored contents.

However, the host player 210 uses a separate EEPROM or firmware because a data space for storing digital content files is externally formed like the flash memory 231 and does not directly interface with the manager program 250. The secure memory 215 may be configured by utilizing a NOR memory space for storing the NOR memory space. In addition, even if the memory module is removed, the stored contents of the secure memory 215 may be stored in the form of so-called ciphertext so as not to decrypt the stored contents externally. The above description of the secure memory 215 is optional for the host player 210 of the present invention.

The embedded certificate is a status code, an identifier of the host player, a key value for encrypting / decrypting digital content, a random number that can be used to generate the key value, and the data integrity of the embedded certificate. It consists of all or part of a predetermined checker field for checking. An embodiment of the embedded certificate will be described later with reference to FIG. 5. Meanwhile, the secure memory 215 region may be filled with NULL in the initial release state of the host player 210 or a specific valid embedded certificate may be recorded, which will be described later with reference to FIGS. 3 and 4. do.

The security module 212 includes a firmware or an integrated circuit for performing a specific encryption algorithm according to the content security processing of the present invention. First, a specific encryption algorithm provided by the security module 212 is preferably a public key based encryption algorithm such as Diffie-Helman, RSA, ECC, etc., but the shared-key or key selection in consideration of the system performance of the host player 210. Vector-based encryption algorithms may be employed, which may be provided in the form of firmware or in the form of integrated circuits. Through such an encryption algorithm, it is possible to improve the security of the security processing system of the digital content according to the present invention, and the control module 211 can efficiently execute a specific encryption algorithm performed according to the present invention through the security module 212. And quickly.

The decryption module 214 is used to perform decryption processing in response to the digital content file read from the flash disk 230 in the encrypted state by the manager program 250. The descrambling key for use in the C) is obtained through the cooperative operation of the control module 211 and the security module 212 based on the built-in certificate stored in the secure memory 215. In the present specification, the encryption / decryption algorithms used by the encryption module 253 and the decryption module 214 are not specific, and may be implemented using algorithms known in the art, such as DES and MD-5.

The manager program 250 according to the present invention is a kind of software installed in a personal computer to perform digital content protection processing on the host player 210. The manager program 250 accesses and flashes the flash disk 230 through a digital connection such as USB. Data may be written to the memory 231 or data may be read in the flash memory 231. According to the digital content protection processing system of the present invention, the manager program 250 reads the certificate file from the flash disk 230 and generates an encryption-key based on the encrypted file, and encrypts the digital content file using the encryption-key. After that it is responsible for the function of copying to the flash disk (230).

The manager program 250 includes a USB automatic detection module 251, an authentication data management module 252, and an encryption module 253. First, when the flash disk 230 is connected via USB, the USB automatic detection module 251 detects the digital connection to recognize the flash disk 230 as a mass storage device (UMS device) according to the standard UMS standard. It works. In addition, the authentication data management module 252 receives the certificate file loaded in the flash memory 231 and determines the validity thereof, and if it is valid, generates an encryption-key based on the certificate file, and if the certificate file does not exist If the authentication request file is loaded, the certificate file is newly issued based on the authentication request file and the function is recorded in the flash memory 231. Meanwhile, the encryption module 253 performs a function of encrypting data of the digital content file transmitted to the flash disk 230 according to a specific encryption-key value.

Meanwhile, although the host player 210 is shown as using the flash disk 230 in FIG. 2, the spirit of the present invention is not limited thereto and should be interpreted as a case of using a general external device. In addition, although the host player 210 illustrated in FIG. 2 is illustrated as not having a built-in nonvolatile memory for storing a digital content file, the spirit of the present invention is not limited thereto. ) Should be interpreted as a device having the capability to host and read and play digital content files therefrom. In addition, although a USB interface is used in FIG. 2, the spirit of the present invention is not limited thereto and should be interpreted as using a digital interface.

3 is a flowchart showing an embodiment of operation of the host player 210 in the content security processing system according to the present invention.

When the host player 210 according to the present invention is powered on (ST301), it checks whether the embedded certificate exists in the aforementioned secure memory 215 (ST302), and if it exists, checks the integrity of the embedded certificate (ST303). If it is determined that the result is valid, the connection of the flash disk 230 is waited (ST305). A preferred embodiment of the above-described embedded certificate is shown in field format (d) of FIG. According to an embodiment of the present invention, the embedded certificate is stored in the secure memory 215, and the host player 210 may be manufactured with a built-in certificate in the secure memory 215 at the time of product release or NULL. It can also be preloaded.

The integrity check ST303 may be performed in various ways. In the simplest case, an error checking field is provided in the embedded certificate to check whether the embedded certificate is valid. It will be described later in detail with reference. The integrity check (ST303) is intended to eliminate the possibility that an incorrect embedded certificate may exist in the secure memory 215 due to a certain factor. In the first place, when an incorrect value is recorded, the memory module may be damaged by an external shock. If the memory module is damaged, a bad memory module is installed, or a new memory module is mounted through system repair.

The host player 210 records the certificate file in the flash memory 231 when the flash disk 230 is connected (ST306). The certificate file is generated by the host player 210 based on the above-described built-in certificate. A preferred embodiment of the certificate file is shown in field format (a) of FIG. Referring to the field formats [(a), (d)] shown in Fig. 5, it is possible to generate a certificate file based on the embedded certificate. By recording the certificate file on the flash disk 230 (ST306), mutual coupling between the host player 210 and the flash disk 230 is performed. The use of the recorded certificate file will be described in detail with reference to FIG. 4.

However, since the flash disk 230 employed in the present invention is a general external device without security, the certificate file is used to prevent a third party from hacking the content security processing system of the present invention by reading the contents of the certificate file. Preferably, the host player 210 and the manager program 250 may be encrypted in a form that can be decrypted, and a specific method may be implemented using a known encryption method such as a public key encryption method or a symmetric key encryption method. However, when the external device 230 used in the host player 210 according to the present invention has sufficient security by itself, the above separate encryption process may be omitted. Meanwhile, in the present specification, it is assumed that one certificate file is recorded on the flash disk 230. However, when a technique such as data management is applied to the flash disk 230, it is also possible to record and manage a plurality of certificate files. .

In step ST306, the host player 210 records the certificate file on the flash disk 230, and sometimes a certificate file having the same contents is already recorded in the flash disk 230. This is a case where the mutual coupling between the host player 210 and the flash disk 230 has been performed before, using a scrambling key that can be obtained based on the certificate file as described below with reference to FIG. 4. The administrator program 250 may have encrypted the digital content file and recorded it on the flash disk 230. Accordingly, the host player 210 obtains a decryption key based on the embedded certificate (ST307), reads the digital content file from the flash disk 230 (ST308), and Decoding processing and decoding processing are performed.

Meanwhile, in the above description, the host player 210 obtains the decryption-key based on the embedded certificate. However, since the built-in certificate and the certificate file are matched with each other, there is no difference in the actual content. Obtaining the key is substantially the same in terms of obtaining the decryption-key based on the certificate file. As described above, whether or not the built-in certificate and the certificate file are matched with each other, referring to the field format (a) of FIG. 5, refer to specific information recorded in the certificate file, for example, a model name or a player identifier. Can be inspected.

Referring to the field formats (a) and (d) of FIG. 5, the host player 210 may directly obtain a decryption-key from the "key value" field of the embedded certificate or certificate file. It may be obtained by performing a predetermined operation on a specific field of an embedded certificate or a certificate file. Further, in step ST309, the host player 210 examines the digital content file read from the flash disk 230 to determine whether it is in an encrypted state, and if it is in an encrypted state, decrypts the key using the decrypted-key. After the decryption process is performed on the data of the file, the decoding process is performed. If the data is not encrypted, the decryption process is unnecessary. The determination of whether the digital content file is in an encrypted state may be performed in various forms. For example, the digital content file may be determined from an extension of the file or may be determined from a specific header format of the file.

On the other hand, if the built-in certificate does not exist in the secure memory 215 of the host player 210 or if the built-in certificate is not valid, first, the connection of the flash disk 230 is waited (ST310) and the connected flash disk 230 is connected. It is determined whether or not the newly issued certificate file exists in step (ST311). In this case, the newly issued certificate file refers to a certificate file newly issued by the administrator program 250 according to the present invention and recorded on the flash disk 230 as described below with reference to FIG. 4. The field format (c) of FIG. In the following, an example is shown.

If there is a newly issued certificate file, first, an integrity check is performed, and if it is valid, it is determined whether or not it matches the content previously requested (ST312). As a result, when matching is confirmed, a built-in certificate is created based on the newly issued certificate file and recorded in the secure memory 215 (ST314).

The new issuance certificate file is issued by the administrator program 250 in response to a request for issuance by the host player 210 and the host player 210 holds data related to the issuance request therein. When the host player 210 requests a new issuance of a certificate file, it preferably generates a random number and inserts it into the authentication request file, and the manager program 250 also inserts the random number into the new issue certificate file. Since it is transmitted to 210, the matching may be determined by comparing the random number values (ST312).

An embodiment of such an authentication request file and a new issuance certificate file are shown in field formats (b) and (c) of FIG. 5, and as shown, a random number field is provided in the authentication request file and the new issuance certificate file. On the other hand, the matching may be determined using a player identifier without using a random number, but it is safe to use a random number because one host player 210 may request a new issue of a certificate file a plurality of times. However, it is also advantageous to determine matchability using player identifiers, so the use of random numbers should be interpreted as optional. Meanwhile, as described above, the host player 210 stores information on a new issuance request of a certificate file. As the storage location, the secure memory 215 is preferable, and the field format (e) of FIG. 5 is stored. An embodiment of the information is shown.

On the other hand, if there is a problem in matching or integrity even if the new issuing certificate file does not exist or exists, the host player 210 writes the authentication request file in the flash memory 231 of the flash disk 230 (ST315). The authentication request file is as described above.

4 is a flowchart showing an embodiment of the operation of the manager program 250 in the content security processing system according to the present invention.

When the manager program 250 according to the present invention is executed (ST401), it waits for the connection of the flash disk 230 through a digital connection such as USB (ST402). When the flash disk 230 is connected, the internal flash memory 231 Check whether there is a specific certificate file (ST403). As described above with reference to FIG. 3, the certificate file is recorded by the host player 210 in step ST306, the preferred embodiment of which is as shown in the field format (a) of FIG.

As a result of the check (ST403), if a certificate file exists in the flash disk 230, the integrity of the certificate file is checked (ST404). If it is determined that the result is valid, an encryption-key is obtained based on the certificate file (ST406). do. The manager program 250 performs an encryption process on the data of the digital content file in the encryption module 253 using the obtained encryption-key (ST407), and stores the digital content file on which the encryption process is completed, on the flash disk 230. Copy to

On the other hand, if the certificate file does not exist in the flash disk 230, or if the certificate file is found to be an error in the integrity check (ST404), the manager program 250 proceeds to step ST408 to flash disk 230 It is checked whether there is a valid certificate request file in the file, and if a valid certificate request file exists, a new certificate file is generated based on the certificate request file (ST409) and recorded in the flash disk 230. On the other hand, if a valid authentication request file does not exist in the flash disk 230, an error is displayed on the screen and the content security processing operation is stopped (ST410).

Preferably, if the administrator program 250 newly issues a certificate file and records it in the flash memory 230, the process proceeds to step ST406 to obtain an encryption-key based on the newly issued certificate file, and then the foregoing. Perform encryption processing on the digital content file as shown. The field formats of the certificate file, the certificate request file, and the newly issued certificate file will be described later with reference to FIG.

5 is a diagram showing an embodiment of a certificate file and a built-in certificate usable in the content security processing system according to the present invention.

In FIG. 5, (a), (b), and (c) show field formats of various data stored in the flash disk 230, and (d) and (e) show secure memory 215 of the host player 210. FIG. Shows the field format of the built-in certificate. In more detail, the various field formats [(a), (b), (c)] are respectively the field format [(a)] of the certificate file recorded by the host player and the field format [(b) of the authentication request file. ), And the field format [(c)] of the certificate file newly issued and delivered by the administrator program 250. The illustrated field formats are only preferred embodiments, and those skilled in the art can easily change these field formats within the scope of the present invention.

In the field formats (a) to (e) of the various types of data shown, the "version" field is information used to match version compatibility between the host player 210 and the manager program 250, and the host player 210. When recording the certificate file and the certificate request file, the administrator program 250 can generate an encryption-key or issue a new certificate file so as to be compatible with it by recording its version value. Further, the "status code" field is information indicating whether these certificate files, certificate request files, and new certificate files are in a normal state. The "model name" field is information indicating the model number of the host player 210 in which these certificate files, authentication request files, and new certificate files are used.

Further, the "player identifier" field may be a unique identifier for identifying the corresponding host player 210 or may be information for identifying a certain host player group. In addition, the "key value" field may be used to encrypt / decrypt data of the digital content file transmitted through the flash disk 230. Since the key value is displayed on the certificate file and the new certificate file, the key value is preferably used. Is scrambled by a specific security algorithm. In addition, the "checker" field is for checking the integrity of the various types of illustrated data, and may be, for example, a CRC code or an Even / Odd bit.

In addition, the "random number" field is a field for recording a randomly generated value, the host player 210 generates a random number when inserting a new certificate file is inserted into the authentication request file, and then connected to the flash disk 230 When a new certificate file of field format (c) is found in the c), it is determined whether the new certificate file corresponds to the certificate file requested by the user, that is, matching. To this end, the host player 210, after recording the authentication request file in the flash disk 230, the random number inserted into the authentication request file in the form of a field format (e), a non-volatile memory space, for example, a secure memory 215 Save it in.

Embodiments of the present invention may include a computer readable information recording medium including program instructions for performing various computer-implemented operations. The computer readable information recording medium may include program instructions, data files, data structures, etc. alone or in combination. The program instructions recorded on the information recording medium may be those specially designed and constructed for the present invention, or may be known and available to those skilled in computer software. Examples of computer-readable information recording media include hardware devices specifically configured to store and execute program instructions, such as hard disks, floppy disks, CD-ROMs, DVD-ROMs, and flash memories. The information recording medium may be a transmission medium such as an optical or metal wire, a waveguide, or the like including a carrier wave for transmitting a signal specifying a program command, a data structure, and the like. Examples of program instructions include machine code, such as produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter.

According to the content security processing system of the host player of the present invention, by effectively preventing illegal copying of digital content files stored on a flash disk of a standard UMS standard in using a host player, which is a digital audio playback apparatus that does not have a built-in flash memory. There is an advantage in that the copyright contained in the digital content file can be protected.

In addition, according to the content security processing system of the host player of the present invention, even if the security device is hacked by performing version management and integrity check of the authentication data, a new version of the authentication data is disseminated as soon as possible to prevent the spread of damage of the hacking. The advantage is that you can.

1 is a diagram conceptually showing an internal configuration of a host player to which the content security processing system of the present invention is applied.

2 is a diagram showing an embodiment of an internal configuration of a content security processing system according to the present invention;

3 is a flowchart showing an embodiment of operation of a host player in a content security processing system according to the present invention;

4 is a flowchart illustrating an embodiment of an operation of an administrator program in a content security processing system according to the present invention;

5 is a view showing an embodiment of a certificate file and a built-in certificate usable in the content security processing system according to the present invention.

<Explanation of symbols for the main parts of the drawings>

210: host player 211: control module

212: security module 213: decoding module

214: decryption module 215: secure memory

230: flash disk 231: flash memory

250: manager program 251: USB automatic detection module

252: authentication data management module 253: encryption module

Claims (11)

(1) a secure memory for storing a built-in certificate; A digital connection for coupling with an external device; Check whether there is a valid built-in certificate in the secure memory. ① If present, create a certificate file-first certificate file-based on the built-in certificate and record it in the external device. ② If not, specify a specific format in the external device. A security module for recording an authentication request file of ③ and obtaining a decryption-key based on the embedded certificate; A decoding module for reproducing data of the digital content file read from the external device; And a decryption module for decrypting data of the digital content file using the decryption-key when the digital content file is encrypted. And (2) a UMS automatic detection module for automatically detecting that an external device is connected through a digital connection; Checks whether there is a valid certificate file-a third certificate file-in the external device. ① If present, obtains an encryption key based on the third certificate file. ② If not, an authentication request of a specific format stored in the external device. An authentication data management module for generating a certificate file -a fourth certificate file-based on the file, recording the same in the external device, and obtaining an encryption-key based on the fourth certificate file; And an encryption module for encrypting data of the digital content file using the encryption key. Content security processing system, characterized in that configured to include. 2. The method of claim 1, wherein the security module of the host player matches the host player in the external device when there is no valid built-in certificate in the secure memory. (1) generate and store the built-in certificate based on the second certificate file if present; and ② record the authentication request file of the specific format in the external device if not present. The method according to claim 1, wherein the authentication data management module of the manager program checks whether an authentication request file of the specific format exists in the external device when the third certificate file does not exist in the external device. And if present, generates the fourth certificate file based on the authentication request file and writes the fourth certificate file to the external device. ② If it does not exist, display an error and stop the security processing operation. Checking whether the host player holds a valid embedded certificate; Generating a certificate file-a first certificate file based on the built-in certificate and recording the result in an external device if the host player inspects the host player; Writing a certificate request file of a specific format in the external device if the host player does not hold the test result; Obtaining, by a host player, a decryption-key based on the embedded certificate; Reading the digital content file from the external device and, if encrypted, decrypting data of the digital content file using the decryption-key; Checking, by the administrator program, whether a valid certificate file-a third certificate file-exists in the external device; Obtaining an encryption-key based on the third certificate file, if it exists, as a result of the inspection of the manager program; As a result of the inspection of the manager program, if it does not exist, a certificate file-a fourth certificate file-is generated based on the authentication request file of a specific format stored in the external device and recorded in the external device and based on the fourth certificate file. To obtain an encryption-key; And encrypting, by the administrator program, the content file using the encryption key and copying the content file to the external device. The host player of claim 4, wherein the host player checks whether the embedded certificate exists in an internal secure memory, and if so, performs the integrity check on a specific checker field in the embedded certificate. Content security processing method characterized by checking whether or not to hold a built-in certificate. The apparatus of claim 4, wherein the manager program checks whether a certificate file exists in the external device, and if so, performs a integrity check on a specific checker field in the certificate file. And checking whether the certificate file exists. The method according to claim 4, wherein if the host player does not hold the valid embedded certificate, the host player checks whether there is a valid certificate file-a second certificate file-matched with the host player in the external device. And generating and storing the embedded certificate based on the second certificate file. ② If it does not exist, recording the authentication request file of the specific format in the external device. 8. The method of claim 7, wherein when the certificate file exists in the external device, the host player compares a specific random number field in the certificate file with a specific random number field recorded by the host player in the authentication request file. And determining whether or not the certificate file is valid by performing integrity check on a specific checker field in the certificate file. The content security processing method according to claim 4, wherein the host player determines whether the digital content file is an encrypted file by parsing a specific header format in the digital content file. The method according to claim 4, wherein the manager program checks whether an authentication request file of the specific format exists in the external device when the third certificate file does not exist in the external device. And generating the fourth certificate file based on the second certificate file and writing the same to the external device. ② If not present, an error is displayed and the security processing operation is stopped. A computer-readable information recording medium having recorded thereon a program for executing the content security processing method according to any one of claims 4 to 10.