JPH10283271A - Cipher key generation method, optical disk, and method and device for information recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the management of a cipher key to improve the operability while preventing wrong use and wrong copy of information. SOLUTION: A cipher key is generated based on a discrimination statement set by a user. The cipher key is recorded in a low-density recording area of an optical disk. At the time of reproducing, the cipher key is read out from the low-density recording area of the optical disk, and the discrimination statement is obtained from this cipher key (S1). The user inputs a discrimination statement in accordance with a discrimination statement input request (SJ). Then, this inputted discrimination statement and the discrimination statement obtained from the cipher key are compared with each other (SK). If they coincide with each other (Y in SL), information designated by the cipher key out of main information recorded on the optical disk is reproduced (SM). The same discrimination statement can be set for plural optical disks different by cipher keys, thus simplifying management.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an encryption key used for information management of an optical disk, and more particularly, to an improvement in generation and recording of an encryption key and information reproduction technology using the encryption key.

[0002]

2. Description of the Related Art As is well known, in an optical disk package medium such as a CD, all information contained in an optical disk is disclosed to an optical disk owner. Therefore, the owner of the optical disk can use all the information included in the optical disk when the optical disk is obtained. For this reason, the price of the optical disk is set for all the information included in the optical disk, and the consumer pays the set price and purchases the optical disk. The idea is to pay for “owning” the information contained in the optical disc.

Generally, an optical disk itself can be manufactured at very low cost. For this reason, the price paid for the optical disc can be considered to be almost related to the quality and quantity of the information contained in the optical disc. In a distribution system that pays for "ownership", even if the information on the optical disc is not required, even if the information on the optical disc is not required, a fee must be paid for all the information included in the optical disc. . In other words, in order to meet the quality and quantity of information worthy of the price, it is necessary to manufacture a wide variety of optical disks whose contents are slightly changed to meet various consumer requirements.
Such a distribution system is not only inconvenient for consumers, but also increases costs and complicates distribution for producers.

[0004] On the other hand, a "super distribution system" is considered as a distribution form in which payment is paid not for "owning" information but for "use" of information. According to this system, the consumer only needs to pay for the information used, and can eliminate the inconvenience of the distribution system for paying for the "ownership" of the information described above, which is a more rational system. Conceivable. In this super-distribution system, information use status and use restriction information are exchanged with a management system via a communication network.

FIG. 4 shows an example of such a super-distribution system. This example is an example applied to game software. Optical disc 900 on which game software is recorded
Is attached as an appendix to the game magazine 902, for example. The user of the game software obtains the optical disk 900 by purchasing the game magazine 902 (see arrow FA).

[0006] On the optical disk 900, a unique ID for each optical disk is recorded. For example, US Pat.
No. 0319 discloses a method of recording information having a much lower density than the recording density of main information (original information of the optical disk) on the information recording surface after manufacturing the optical disk. Recording of information in the low-density recording area is performed by irradiating a powerful laser beam or the like to permanently deform the optical disk substrate or the reflective film on the substrate. The linear recording density of low-density information is, for example, 1/10 to 1/10 of the recording density of main information.
00, preferably about 1/40 to 1/400.

On the other hand, a personal computer (or player) 904 for reproducing the optical disk 900 is provided with a connector and a communication port, and is connected with an IC card 906 and a modem 908, respectively. The IC card 906 stores in advance the game software reproduction limit data, and this data is reduced every time the game software is reproduced. The modem 908 is connected to the management computer 910 of the game software supplier through a communication path. In the management computer 910, setting of a playback frame and collection of a playback fee are performed.

For example, the user sets the optical disc 900 on the personal computer 904. And I of the optical disk
D and a drive No. indicating a drive for reproducing the optical disc 900, an ID of a game software to be reproduced, an ID of a personal computer as a reproducing apparatus, an ID of an IC card, and the like are transmitted to the management computer 910 by the personal computer 904 (arrow FB). reference). Management computer 910
Then, an encryption key (or a password) is generated and transferred by combining the transferred information (see arrow FC). In the simplest example, when the ID of the optical disk is “123”, the drive number is “122”, and the title key of the game software to be used is “666”, the encryption key is “421”. In the personal computer 904, the ID of the optical disc "12
3 ", the drive number" 122 "and the encryption key" 421 "input by the user. Then, the total is “666”
This is the title key to be reproduced. In the personal computer 904, the game software of the title key “666” is reproduced.

As described above, the user once contacts the software supply side before playing back the optical disk, and obtains an encryption key for using necessary information. Then, information is used using the encryption key. In this example, of many game software stored on the optical disc 900, the one corresponding to the encryption key is reproduced. The price for using the information is subtracted from the amount stored in the IC card 906 in advance. The user can enjoy the game software within the range of the reproduction limit of the IC card 906.

According to such a system, even if there is an optical disk, the information cannot be used without the encryption key, so that the illegal copy of the optical disk itself has no meaning and its prevention can be achieved. In addition, since the ID unique to the optical disk is used to generate the encryption key,
It is possible to set an encryption key for each optical disk, and it is not possible to illegally use the encryption key repeatedly.

[0011]

However, according to the above-mentioned method, since different encryption keys are set for each optical disk, the user needs to manage those encryption keys. In particular, when there are a large number of optical disks, the management thereof requires considerable trouble. That is, a different encryption key must be input each time the optical disk is reproduced. Therefore, from the point of view of the information provider, the security against the fraud is increased, which is very convenient. However, from the point of view of the information user, the encryption key is different for each piece of information desired to be used, which imposes a considerable burden, and is not necessarily convenient. Not good.

The present invention focuses on the above points,
An object of the present invention is to provide an encryption key generation method, an optical disk, an information reproduction method, and an apparatus thereof that can simplify the management of encryption keys and improve usability while preventing unauthorized use and illegal copying of information. It is.

[0013]

In order to achieve the above object, an encryption key generating method according to the present invention is provided in which an optical disk (10) is recorded in an area which does not affect main information, for example, in a low density recording area (12). Setting an identification sentence used in place of the encryption key when reproducing the main information of the optical disc in a method of generating an encryption key used for reproducing the main information of the optical disc (SB); Generating the encryption key based on the identification sentence set by (SD) (SD). An optical disk according to the present invention is characterized in that the encryption key generated by the above method is recorded in an area that does not affect the main information.

According to the information reproducing method of the present invention, a step of reading the encryption key from an area which does not affect the main information of the optical disc to obtain the identification text (SI); a step of inputting the identification text (SJ); Comparing the obtained identification text with the identification text obtained from the encryption key (SK); When both match (Y in SL), of the main information recorded on the optical disc, Reproducing (SM) the information specified by the encryption key.

The information reproducing apparatus of the present invention comprises: input means (26) for inputting a preset identification sentence; reproducing means (14, 20) for reproducing an optical disc; an identification sentence inputted by the input means; Reproduction control means (16) for comparing the identification text obtained from the encryption key read by the reproduction means and controlling the reproduction of the main information of the optical disc by the reproduction means; .

According to the present invention, the user uses a preset identification sentence instead of the encryption key. At the time of reproduction, this identification sentence is referred to, and when a correct identification sentence is input, reproduction of the corresponding main information is permitted.

The above and other objects, features and advantages of the present invention will be apparent from the following detailed description and the accompanying drawings.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail in the order of generation of an encryption key, recording thereof, and reproduction of information.

[Generation and Recording of Encryption Key] FIG. 1 is a flowchart showing a procedure of generation and recording of an encryption key according to one embodiment of the present invention. In this figure, it is assumed that there is software (title) desired by the user (step SA in FIG. 1). Then, the user sets a desired identification sentence (password) (step SB). Then, the user sends the set identification text to other necessary information, for example, personal information of the user for paying for the software (user registration ID for the software supplier, credit card registration number, bank account number, etc.). , Along with information such as the title of the desired software, to the software supplier (or agency) (step S
C).

The software supplier generates an encryption key based on the information and an appropriate algorithm (step SD). That is, using the identification text desired by the user, an encryption key is generated so that all the software desired by the user can be used. The encryption key contains data such as identification text, reproducible software, and personal information as necessary. The software supplier is the price (charge) for using the information
Instead, the encryption key is written to the corresponding optical disk (step SE). For example, an encryption key is written in the low-density recording area described above. Then, the optical disk on which the encryption key is written is sent to the user. The software supplier may return the encryption key to the user in exchange for the price. In this case, the user himself writes the encryption key on the corresponding optical disk.

[0020]

[Reproduction of Optical Disk] Next, reproduction of the optical disk on which the encryption key is recorded as described above will be described. FIG. 2 shows the procedure, and FIG. 3 shows an example of the reproducing apparatus. It is assumed that the above-described encryption key is recorded in the low-density recording area 12 of the optical disk 10.
When the optical disc 10 is set on the reproducing unit 14, the recording discriminating unit 18 of the reproducing control unit 16 checks whether or not an encryption key signal is recorded (step SG in FIG. 2). When the recording discriminating unit 18 determines that there is no encryption key signal (N in step SG), only the non-restriction information that is not permitted to be reproduced or that does not require the encryption key is reproduced by the reproduction unit 14 (step S <b> 1). SH). The reproduction information is output at the output unit 20.

On the other hand, when the recording discriminating section 18 judges that there is an encryption key signal (Y in step SG), the low-density recording area 12 is reproduced, and the encryption key information, the optical disk identification information, the reproduction permitted title, The personal information and the like are read (step SI). Next, in the reproduction control unit 16, the identification sentence input requesting unit 24 requests the user to input an identification sentence (step SJ). That is, the effect is output to the output unit 20 as audio or video by the identification sentence input request unit 24. It is assumed that the user has input an identification sentence through the input unit 26 based on the input request (step S
K), the appropriateness is determined by the identification sentence determination unit 22 (step SL). As a result, when the identification sentence input by the user matches the identification sentence read from the low-density recording area 12 (Y in step SL), the software whose title is permitted to be reproduced corresponding to the identification sentence is It is reproduced (step SM). However, if they do not match (N in step SL), only the non-restriction information for which reproduction is not permitted or for which no encryption key is required is reproduced by the reproduction unit 14 (step SH).

As described above, according to this embodiment, the encryption key is set based on the identification text desired by the user. That is, assuming that the identification sentence is a key, a keyhole of each optical disc is generated in accordance with the key. Therefore, at the time of information reproduction, the user only has to input an identification sentence instead of the encryption key, and thus the following advantages are provided. (1) The user can arbitrarily set an identification sentence or a password. Therefore, for example, the same identification statement can be set for all the owned optical disks, and it is not necessary to remember the identification statement for each optical disk.

(2) When it is desired to add software to be used to an optical disc on which a plurality of pieces of information, for example, a plurality of game software are recorded, a new encryption key is required. The same identification sentence as before the addition can be used, which is convenient. In this case, a new optical disk in which an encryption key for adding software is recorded is required. However, since the optical disk itself is inexpensive, the burden on the user is small. Of course, it is also possible to set different identification sentences for a plurality of pieces of information.

(3) As in the super-distribution system, a fee is charged for the information itself, so that the disk is distributed at low cost. Since the user only has to pay for the information part which he needs, there is no unnecessary expense. Since optical disks are distributed at extremely low prices, piracy is not achieved. In addition, the distribution destination of the optical disk is ascertained at the time when the user requests the distribution of the encryption key, so that the user management can be performed reliably. Therefore, it is easy to grasp the illegally copied optical disk. Furthermore, since an inexpensive optical disk can be obtained and the contents can be purchased after confirming the contents in the non-encrypted portion of each software, distribution becomes active.

The present invention has a number of embodiments,
Various modifications can be made based on the above disclosure. For example, the following is also included. (1) The encryption key generated by the software supplier does not necessarily have to be the identification text itself, and may be, for example, processed in a manner that is invisible to the user. In this case, the identification text is generated by performing the reverse operation when recording the encryption key or reading the encryption key from the optical disk. Similarly, it is also possible to perform arithmetic processing on the reproduction permission title, personal information, reproduction permission level, and the like, to record them in the low-density recording area, and to enhance confidentiality.

(2) The recording of the encryption key information in the low-density recording area can usually be performed only once. In such a case,
If the identification sentence set by the user becomes inconvenient, it is necessary to prepare a new optical disk. However, since the optical disk itself is provided at a very low price, for the software that has already received the price for the information, the software supplier collects the previous optical disk and then re-encrypts the encryption key only with a fee (or free of charge). If provided, no particular inconvenience occurs.

(3) In the above embodiment, a part of the information recorded on the optical disk is permitted to be reproduced by the identification text. However, the reproduction of the entire optical disk may be permitted.

(4) In the above-described embodiment, one identification sentence is described for one optical disk. However, a plurality of identification sentences can be included in the encryption key, and a plurality of information in the optical disc can be included. Alternatively, a different identification sentence can be set.
In this case, it is possible to restrict the reproduction of an arbitrary combination of titles, which is effective when one person wants to use one optical disk. For example, when the game software GA, GB, GC, GD,... Are recorded on one optical disc, the user A uses the game software BC with the identification sentence “a”, and the user B uses the identification sentence “b”. And the game software GA, GB, and GC are used.

In this case, if, for example, 4 bytes = 32 bits are assigned as a title key for specifying the software to be used, permission / non-permission of one title can be made to correspond to each bit. Can specify software of 32 titles.

(5) As the identification sentence, various things such as numbers, characters, and symbols may be used. For example, the password is about 1 to 30 bytes including a plurality of digits of a password, a name, and a short sentence. (6) For example, in DVD, BCA (Burst Cutting Are
a) The region is suitable as a low-density recording region.

[0031]

As described above, according to the present invention,
Since the encryption key is set based on the identification text desired by the user, it is possible to effectively prevent unauthorized use and illegal copying of information and to simplify the management of the encryption key to improve the usability. is there.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a procedure for generating and recording an encryption key according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a procedure of reproducing an optical disc in the embodiment of the present invention.

FIG. 3 is a block diagram showing an embodiment of a reproducing apparatus of the present invention.

FIG. 4 is a diagram showing an example of a super distribution system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Optical disk 12 ... Specific information area 14 ... Reproduction part 16 ... Reproduction control part 18 ... Recording discrimination part 20 ... Output part 22 ... Identification sentence judgment part 24 ... Identification sentence input request part 26 ... Input part

Claims (4)

[Claims] 1. A method for generating an encryption key recorded in an area that does not affect the main information of an optical disc and used for reproducing the main information of the optical disc, comprising: Setting an identification sentence to be used in place of the encryption key; and generating the encryption key based on the identification sentence set thereby. 2. An optical disk, wherein an encryption key generated by the method according to claim 1 is recorded in an area that does not affect main information. 3. The step of reading an encryption key from an area which does not affect the main information of the optical disk according to claim 2 to obtain the identification sentence; the step of inputting the identification sentence; Comparing with an identification sentence obtained from the key, whereby when both match,
Reproducing the information specified by the encryption key out of the main information recorded on the optical disc. 4. An information reproducing apparatus for reproducing main information of an optical disk according to claim 2, wherein: input means for inputting a preset identification text; reproducing means for reproducing the optical disk; identification text input by said input means. Reproduction control means for controlling the reproduction of the main information of the optical disk by the reproduction means by comparing the identification text obtained from the encryption key read by the reproduction means with the identification key;
An information reproducing apparatus comprising: