CN100426405C - Data scrambling and decoding method for optic disc storage - Google Patents

Abstract

A data scrambling and decoding method for optical disc storage, which uses the original password to scramble user data; the original password required for user data descrambling is multi-encrypted and used as the optical disc encryption password—analog password; the user data after scrambling is Data and analog passwords are recorded on the disc in a separate or mixed manner, and synchronous or asynchronous timing is also used for decryption; special IC serial number management is used to coordinate the relationship between content providers, master disc manufacturers and chip manufacturers, The dedicated IC is responsible for converting the encrypted digital password into an analog password, and each IC has a special serial number, which is forced to appear on the master disc and the optical disc. It increases the difficulty of CD duplication, which is conducive to the establishment of a copyright mutual trust mechanism that can be monitored.

Description

Data scrambling and decoding method for optical disc storage

technical field

The invention belongs to the technical field of optical disc storage, specifically relates to an optical disc encryption method, and can be applied in the fields of consumer optical storage, IT optical storage, and the like.

technical background

At present, CSS, the main copyright protection technology of DVD, has been cracked. The CD industry has introduced a new copyright protection technology, AACS. The password word length of AACS is increased to 128 bits. Also announced BD+ and ROM Mark technology to strengthen copyright protection capabilities. The core of BD+ is that when the password of the DVD player is cracked, the password can be updated. ROM Mark is a physical mark on the disc. Only authorized users can access this mark. This will increase the difficulty of mass copying and piracy. The core of CSS, AACS, and BD+ is to maintain the password on the DVD player and use it to decrypt the encrypted audio-visual data. This method is a mechanism that is relatively easy to implement, but its problem is that once the password is cracked, the entire system will be destroyed. The system will all fail, and, considering compatibility issues, even a remedy is not easy to do; for example, the DVD's CSS, which has been cracked, cannot be remedied. AACS - The basic principle is similar to CSS. Once the password is cracked, the entire password system will be completely invalid and cannot be remedied. Although BD+ can update passwords, considering the wide diversity of users and the update problem of DVD players, the operability of BD+ is still to be considered. ROM Mark considers the problem from another angle. He requires the reliability of the technical system and the manufacturing system to be very good and to cooperate with each other. In fact, disc encryption technology is a very complicated system, which involves disc manufacturers, machine manufacturers, user habits (machine users and PC users) and storage and exchange methods. copyright protection.

Contents of the invention

The purpose of the present invention is to provide a data scrambling and interpretation method for optical disk storage, overcome the shortcomings of the current optical disk copyright protection technology, adopt the block matching disk encryption technology based on mixed signal processing, and use this technology to build chip manufacturers, master A reasonable and monitorable mutual trust mechanism between disk manufacturers and content providers, to achieve a copyright protection system that can be accepted by consumers and well protect the copyright of optical disks.

The technical solution of the present invention is: a data scrambling and interpretation method for optical disk storage, characterized in that:

User data is scrambled with the original password;

The original password required for user data descrambling is multi-encrypted as the disc encryption password;

Optical disc encryption code - analog password is a set of analog signals, which can be recorded and read with axial or radial optical signal characteristics along with the data track on the optical disc, or can be recorded and read with a separate analog signal encryption layer Appears in the form of; the original password becomes the analog password through multiple encryption: original password → (digital encryption) digital password → (conversion encryption) analog password;

Record the scrambled user data and analog password on the optical disc in a separate or mixed manner, and use synchronous or asynchronous timing for decryption;

Use dedicated IC serial number management to coordinate the relationship between content providers, master disk manufacturers and chip manufacturers. The dedicated IC is responsible for converting encrypted digital passwords into analog passwords. Each IC has a dedicated serial number , the serial number is mandatory on both master and disc.

The data scrambling and interpretation method for optical disc storage as described above is characterized in that the specific implementation steps are as follows:

①The content provider determines the original password that meets certain rules. The original password should be a set of 0, 1 character strings. Depending on the user's requirements for encryption levels, original passwords of different lengths can be used. The general principle is that they are generated at the end The simulated password will cover the entire disc. On the one hand, this flexible mechanism can adapt to different requirements, and can also avoid the reduction of the difficulty of piracy caused by simple rules.

②Encode the original password. The function of this encoding is to perform a digital encryption on the original password. This encoding is unidirectional, and its cracking requires a large amount of calculation, and its decoding algorithm is very simple. In this way, the encoding rule determines In the future, the encoding rules of multiple modes can be accommodated in the decoding IP, and multi-mode encryption can be supported, so that each disc can correspond to an independent password and increase the security of the password; each mode has different parameters, and the modes and parameters are determined by The content provider independently selects and sets for the disc, and the content provider encodes the original password using the password encoding rules and the mode and parameters selected by the content provider to obtain a digital encrypted password.

③Convert digital passwords into analog passwords. The conversion rules include signal definition methods and modes of analog passwords. The parameters of the conversion rules are set by the content provider for the disc separately. The set parameters convert the digital password to obtain the analog password.

④ After the master disc manufacturer mixes the analog password with the scrambled disc data, it records them on the master disc in a synchronous or asynchronous manner according to specific requirements in a block matching manner.

⑤Interpretation: The dedicated processing module integrated in the main chip of the system performs AD conversion on the analog password to obtain the encrypted digital password, and then uses the decryption IP to decrypt the original password of the disc, and then uses the original password to descramble the disc data. Get end user data. Since the process is handled by a module packaged in a single chip, no password is lost during the conversion process, decryption process, and descrambling process.

The digital encryption of the original password is private (content provider), the decryption method is public (IC manufacturer), the analog encryption of the password is private (disc manufacturer), the decryption method is public (IC manufacturer), The data scrambling method is private (content provider), and the descrambling method is public (IC manufacturer).

The present invention mainly includes the following contents:

1. Original password multiple encryption rules

This rule adopts trapping one-way gate or similar encoding method, and its encoding process is private, and the parameters that determine its encoding characteristics can be determined by the content provider. The decoding IP is public and can be integrated into the main chip by authorized chip manufacturers. Because the encoding method adopted has a one-way feature, its cracking requires a large amount of calculations, which greatly increases the difficulty of piracy. Moreover, because each disc has a separate password, even if the password of a disc is cracked, there is no problem. It will cause the collapse of the whole system.

2. Conversion rules for converting digital passwords to analog passwords

According to the frequency characteristics and amplitude characteristics of the analog quantity, the rule uses frequency modulation or amplitude modulation to convert the digital code into a set of analog signals. Because it is very difficult to accurately copy the analog signal, and the block matching with the data It is difficult to accurately and completely reproduce the analog signal throughout the entire disc without knowing the digital code and conversion rules. Therefore, it is difficult to realize disk-to-disk copying by reading signals.

3. Simulate the loading and reading of the password on the CD

The analog code is recorded on the optical disc according to the track along with the scrambled data, and the analog signal can be synchronous or asynchronous with the data block. Wherein, the analog signal can be realized by changing the physical characteristics of the medium (such as refractive index or reflectivity or polarization state) in the axial or radial direction, and can also be realized by using an independent encryption layer. When reading, after separating the data signal and the password signal, the AD conversion of the password signal is completed by an independent processor module, and the accuracy of the conversion will ensure the correctness of the password.

4. Data scrambling technology based on block matching on-disk cipher

Similar to the scrambling principle of digital TV, the data scrambling of the synchronous on-disk cipher uses synchronous or asynchronous ciphers to scramble the data in blocks, and the scrambled data can be read and written in the usual sense. Interference, you will get a bunch of garbled characters without any practical meaning. At the same time, the block-scrambled password will fully consider the impact of bit errors to avoid the failure of the entire data block caused by password errors. Due to the continuous enhancement of the capabilities of the current embedded processors, there is no computing bottleneck in data descrambling.

5. A monitorable copyright mutual trust mechanism among chip manufacturers, master disk manufacturers and content providers

The conversion of digital passwords into analog passwords is realized by special ICs according to the selection of modes and parameters, and each special IC has a separate serial number, which will be recorded on the master disc and the optical disc. Since this cryptographic system involves chip manufacturers, master disc manufacturers and content providers, it is necessary to establish a monitorable copyright mutual trust mechanism among the three, which includes the management and coordination of cryptographic encryption technology, master disc manufacturers and chip Manufacturer's authorization and management, disc copyright monitoring technology.

The beneficial effects of the present invention are:

1. Multiple encryptions and analog passwords increase the difficulty of CD copying.

2. Each disc has a separate password, even if the password of a disc is cracked, it will not cause the collapse of the entire encryption system.

3. Synchronous scrambling technology increases the difficulty of user data decryption.

4. The separation of mechanism and strategy is conducive to the establishment of a copyright mutual trust mechanism that can be monitored.

Description of drawings

Fig. 1 is a block diagram of the process of scrambling and decoding data stored in an optical disc according to an embodiment of the present invention.

Detailed ways

The content of the present invention will be further described in detail below in conjunction with specific implementation steps, but the scope of protection of the present invention is obviously not limited to the following examples.

1. The content provider determines the original password that meets certain rules for the content to be produced. For example 11001xxxxxxx01011. At the same time, the content provider digitally scrambles the data with the original password.

2. The encryption system digitally encrypts the original password according to the one-way encryption principle, and obtains a set of encrypted digital passwords after encryption, such as: 1011XXXXXXXXXXXX...XXXXXXXXXX11001. This encryption process is the responsibility of the content provider.

3. The encryption system converts digital passwords into analog passwords according to the one-way encryption principle, and obtains a specific analog waveform after conversion, for example, the superposition of trigonometric functions of different frequencies and amplitudes. This encryption process is the responsibility of the disc manufacturer.

4. When descrambling, after the front-end separates the data and the password, the dedicated processing module integrated in the main chip of the system performs AD conversion on the analog waveform to obtain the encrypted digital password, such as: 1011XXXXXXXXXXXX……XXXXXXXXXX11001. Then use the decryption IP to decrypt the original password of the disc, such as 11001xxxxxxx01011, and then use the original password to descramble the disc data to obtain the end user data.

5. The encryption IC that converts digital passwords into analog passwords has a special serial number. This serial number is a globally unique identification. Through this identification, the master disk manufacturer can be tracked. Only authorized IC manufacturers can manufacture encrypted ICs. The provider has the right to know the serial number, and at the same time, the serial number will be mandatory on the master and CD.

Claims (2)

1, a kind of data scrambling, deciphering method that is used for optical disc storage is characterized in that:

(1) data scrambling: user data adopts original password scrambling, original password to encrypt and generates the cdrom encryption password;

The original password that the user data descrambling needs through behind the multi-enciphering as the cdrom encryption password---promptly simulate password, with the user data after the original password scrambling with simulate password and be recorded on the CD in the mode of separating or mixing;

The cdrom encryption password is one group of simulating signal, and this simulating signal is followed the data-track on the CD, adopts axially or light signal feature radially writes down and reads, perhaps with the form appearance of an independent simulating signal code layer; Original password generates the approach of simulation password through multi-enciphering: (a) original password generates numerical ciphers through digital encryption; (b) numerical ciphers is encrypted through conversion and is generated the simulation password;

(2) data are understood: the deciphering of cdrom encryption password, the descrambling of data of optical disk;

User data after the scrambling is recorded on the CD in the mode of separating or mixing with the simulation password, also adopts synchronous or asynchronous sequential to carry out during deciphering; Isolate the simulation password earlier, by the dedicated processes module that is integrated in system's master chip the simulation password is carried out numerical ciphers after AD is converted to encryption again, obtain the original password of CD then with deciphering IP deciphering, with this original password data of optical disk is carried out descrambling at last, obtain end user data;

Employing application-specific integrated circuit sequence number manages the relation between coordinating content provider, stamper manufacturer and the chip manufacturer, this application-specific integrated circuit is responsible for converting the numerical ciphers after encrypting to the simulation password, each IC has a special sequence number, and this sequence number is forced to appear on stamper and the CD.

2, the data scrambling of optical disc storage as claimed in claim 1, deciphering method is characterized in that concrete implementation step is as follows:

1., determine to meet the original password of certain rule by content supplier, this original password is one group of 0,1 character string, according to the requirement difference of user to secret grade, adopt the original password of different length, total principle is that the last simulation password that generates will cover whole CD;

2., original password is encoded, the effect of this coding is that original password is carried out digital encryption one time, and this coding has one-way; After coding rule is determined, the coding rule that contains a plurality of patterns in the decoded ip, and support composite mode to encrypt, each pattern has different parameters, pattern and parameter are selected for this CD separately by content supplier and are set, content supplier encodes to original password with the pattern and the parameter of cryptography rule and oneself selection, obtains the Crypted password of numeral;

3., numerical ciphers is converted to the simulation password, the rule of this conversion comprises signal definition mode and the pattern of simulating password, the parameter of this transformation rule is set for this CD separately by content supplier, stamper manufacturer changes numerical ciphers according to the parameter of transformation rule and content supplier's setting, obtains simulating password;

4., after stamper manufacturer will simulate password and data of optical disk after the scrambling will mix, the mode according to the piece coupling records on the stamper with the method for synchronization or asynchronous system;

5., understand: the simulation password is carried out numerical ciphers after AD is converted to encryption by the dedicated processes module that is integrated in system's master chip, obtain the original password of CD then with deciphering IP deciphering, with this original password data of optical disk is carried out descrambling again, obtain end user data.

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