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Description  |
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TECHNICAL FIELD
The present invention relates to an optical disk, an optical disk system and a cryptocommunication method.
BACKGROUND
In recent years, with the increased use of networks such as the Internet and optical CD ROM disks, network soft key distribution for optical ROM disks has increased. Also, electronic commercial transactions have increased.
Soft key electronic distribution systems for CD-ROM media have been used. In conventional systems, it is known to give passwords and decipher the enciphered soft ciphers recorded on the CD-ROMs in advance. When CD-ROMs are used, however, it is
not possible additionally to record on the disks, so that it is not possible to individually set IDs for respective disks. Therefore, one password would release the ciphers of all the disks manufactured from the same original disk. For this reason,
when CD-ROMs are used, it is necessary to install the disks' IDs on the hard disks of personal computers, or mail to users IDs prepared centrally.
In electronic distribution systems with conventional optical disks and/or optical disk systems, there is a need to provide the disks and/or systems with IDs and/or cipher keys. It is an object of the present invention to simply provide IDs and
cipher keys for ROM disks in electronic distribution systems.
SUMMARY OF THE INVENTION
To achieve the objects of the present invention, the pit portions of optical disks are provided with an additional recording area or Burst Cutting Area (hereinafter abbreviated as BCA) overwritten with a bar code and, when the disks are
manufactured, IDs differing for each disk and, according to the need, cipher keys for communication and decoding keys for decoding key cipher texts for communication, are recorded individually in the BCA areas. As a result, when the disks have been
distributed to users, the user ID numbers, the cipher keys for transmission for communication, and the decoding keys for reception are distributed automatically to the users. It is therefore possible to omit some of the procedures that complicate
conventional systems. Also, cryptocommunication and the identification of disks are made possible at the same time.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow chart of an optical disk according to an embodiment of the present invention.
FIGS. 2a-c are cross sections and results of trimming with a pulse laser according to an embodiment of the invention.
FIGS. 3a-g show the signal reproduction waveforms at a trimming portion according to an embodiment of the invention.
FIG. 4 is a block diagram of a reproducer according to an embodiment of the invention.
FIG. 5a shows the waveform of a reproduced signal at a BCA part according to the invention. FIG. 5b shows dimensional relationships of a BCA part according to the invention.
FIG. 6 shows a method of cryptocommunication and a cipher key method by means of a password according to an embodiment of the present invention.
FIGS. 7a-c show the format of a BCA according to the invention.
FIG. 8 shows a method of cryptocommunication and a method of unlocking a cipher with a password according to an embodiment of the invention.
FIG. 9 shows a procedure for operation of a disk, the content part of which may have been licensed, according to an embodiment of the invention.
FIG. 10 is a block diagram of an example wherein a BCA has been recorded in a RAM disk according to an embodiment of the present invention.
FIG. 11 is a block diagram of a method or system for prevention of unauthorized copying according to an embodiment of the invention.
FIG. 12 is a flow chart depicting preventing unauthorized copying according to an embodiment of the invention.
FIG. 13a is a plan view and FIG. 13b is a cross section of an optical disk, on the BCA of which an article or commodity bar code has been printed, according to an embodiment of the invention. FIG. 13c shows a method or producing an optical disk
according to an embodiment of the invention.
FIG. 14 is a block diagram of a POS settlement system with a ROM disk having a BCA and a POS terminal according to an embodiment of the invention.
FIG. 15 is a flow chart of cipher release in and between a press company, a software company and a selling store, according to an embodiment of the present invention.
FIGS. 16 and 17 are flow charts (Parts 1 and 2, respectively) of steps of enciphering and decoding cipher data with a disk ID and/or the like according to an embodiment of the invention.
FIGS. 18, 19 and 20 are flow charts (Parts 1, 2 and 3, respectively) of communication cipher key distribution and cryptocommunication with a BCA according to an embodiment of the invention.
FIGS. 21, 22 and 23 are flow charts (Parts 1, 2 and 3, respectively) of an electronic settlement system with a BCA according to an embodiment of the present invention.
FIG. 24 is a block diagram of a method of recording and reproducing for recording limitation to one RAM disk with a BCA according to an embodiment of the invention.
At the end of this specification is appended a list identifying items corresponding to the reference numerals used in the aforementioned drawings, that listing being in consecutive numerical order of the reference numerals.
DETAILED
DESCRIPTION OF THE INVENTION
The present invention will be described on the basis of a number of embodiments. Herein, an additional recording area using the BCA system is referred to as a `BCA area`, and data recorded in a BCA is referred to as `BCA data`. In addition,
first identification data is referred to as `ID` or `disk ID`.
FIG. 1 shows a typical process for producing a disk with a BCA. The first cipher key 802, such as a public key, is used by a cipher encoder or scrambler 803 to encipher contents 777 into the first cipher 805. An 8-16 modulator 917, such as a
mastering unit, modulates the first cipher 805. A laser records the modulated signal as pits in the first recording area 919 of an original disk 800. A molding machine 808a uses the original disk 800 to mold disk-like transparent substrates (not
shown). A reflecting film making machine 808b forms reflecting Al films, and makes single-sided disks 809a and 809b which are each 0.6 millimeter thick. A bonding machine 808c laminates these disks together to make a completed disk 809. A trimming
unit 807 modulates the disk ID 921, the first cipher decoding key 922, or the second cipher key 923 for Internet communication in the second recording area 920 of the completed disk 809, with a Phase Encoding-Return to Zero (PE-RZ) modulator 807a, which
combines PE modulation and RZ modulation. A pulse laser 807b effects BCA trimming to make a disk 801 with a BCA. Because laminated disks are used, it is not possible to alter the BCA inside, and thus the completed disk can be used for security.
A BCA will next be explained briefly.
As shown in FIG. 2a, a pulse laser 808 trims the reflecting aluminum films of the two-layer disk 801 in a BCA to record a stripe-like low reflection part 810 on the basis of a PE modulating signal. As shown in FIG. 2b, BCA stripes are formed on
the disk. If the stripes are reproduced by a conventional optical head, the BCA has no reflecting signal. Therefore, as shown in FIG. 2c, gaps 810a, 810b and 810c are produced, where the modulating signal is missing. The modulating signal is sliced at
the first slice level 915. But, the gaps 810a-c have a low signal level, and can therefore be sliced easily at the second slice level 916. As shown with the recorded and reproduced waveforms in FIGS. 3a-3g, it is possible to reproduce the formed bar
codes 923a and 923b by level-slicing them at the second slice level 916 by a conventional optical pickup as shown in FIG. 3e. As shown in FIG. 3f, the waveforms of the codes are shaped by a LPF filter so as to PE-RZ decode the codes. As shown in FIG.
3g, a digital signal is output.
With reference to FIG. 4, the decoding operation will be explained. A disk 801 with a BCA includes two transparent substrates, which are laminated with a recording layer 801a between them. The recording layer may either be a single layer 801a
or include two recording layers 800a and 800b. If there are two layers, a BCA flag 922 is recorded in the control data of the first recording layer 800a, which is adjacent to the optical head 6. The flag 922 indicates whether a BCA is recorded or not.
Because a BCA is recorded in the second layer 800b, the first recording layer 800a is focused on first, and the optical head 6 is moved to the radial position of the control data 924 in the innermost edge of the second recording area 919. The control
data is main data, and has therefore been Eight to Fourteen Modulation (EFM) 8-15 or 8-16 modulated. Only when the BCA flag 922 in the control data is `1`, a single/double layer switching part 827 focuses on the second recording layer 800b to reproduce
the BCA. If the signal is sliced by a level slicer 590 at the general first slice level 915 as shown in FIG. 2c, it is converted into a digital signal. This signal is demodulated in the first demodulation part by an EFM demodulator 925, an 8-15
modulator-demodulator 926 or an 8-16 modulator-demodulator 927. An ECC decoder 36 corrects errors, if any, and outputs main data. The control data in the main data is reproduced and only if the BCA flag 922 is 1 is the BCA read. When the BCA flag 922
is 1, a CPU 923 orders the single/double layer switching part 827 to drive a focus adjustment part 828, switching the focus from the first recording layer 800a to the second recording layer 800b. At the same time, the optical head 6 is moved to the
radial position of the second recording area 920, that is, for the DVD standard, the BCA is recorded between 22.3 and 23.5 mm from the inner edge of the control data. Then the BCA is read. Reproduced in the BCA area is a signal with a partially missing
envelope as shown in FIG. 2c. By setting in the second level slicer 929 the second slice level 916 of which the quantity of light is smaller than that of the first slice level 915, it is possible to detect the missing parts of the reflecting portion of
the BCA, and a digital signal is output. This signal is PE-RZ demodulated by the second demodulation part 930, and ECC decoded by an ECC decoder 930b so as to output BCA data, which is auxiliary data. Thus, the first demodulator 928, operative
according to, 8-16 modulation demodulates and reproduces the main data, while the second demodulation part 930 operative according to PE-RZ modulation demodulates and reproduces the auxiliary data, that is, the BCA data.
FIG. 5a shows the reproduced waveform before passage through a filter 943. FIG. 5b shows the working size accuracy (precision) of the slits of the low reflecting portion 810. It is difficult to make the slit width less than 5 mm. In addition,
if the data is not recorded inward radially from 23.5 mm, it will not be properly reproduced. Therefore, for a DVD, because of the limitations of the shortest recording cycle of 30 mm and the maximum radius of 23.5 mm, the maximum capacity after
formatting is limited to 188 bytes or less.
The modulating signal is recorded as pits by the 8-16 modulation mode, and a high frequency signal such as the high frequency signal part 933 in FIG. 5a is obtained. However, the BCA signal is a low frequency signal like low frequency signal
part 932. Thus, if the main data complies with the DVD standard, it is a high frequency signal 932 which is about 4.5 MHz or less, shown in FIG. 5a, and the auxiliary data is a low frequency signal 933 which is 8.92 ms in period, that is, about 100 kHz. It is therefore relatively simple to frequency-separate the auxiliary data with a LPF 943. A frequency-separating method 934 as shown in FIG. 4, including the LPF 943 can easily separate the two signals. In this case, the LPF 943, may be simple in
structure.
The foregoing is an outline of the BCA.
With reference to FIG. 6, the overall system of a cipher software unlatching system, narrowed down to the operations of password issue, cryptocommunication, and orderer certification, will be described. The steps in a press factory are nearly
the same as in FIG. 1, so the original disk 800 and the completed disk 809 are not shown.
In a press factory 811, a cipher encoder 812 enciphers the data in the plaintexts 810 of the first to the `1- m`th contents or scrambles the picture signals therein with the first to `1- m`th cipher keys 813, respectively. The data or the
signals are then recorded on an original optical disk 800. Disk-like substrates 809 are pressed from the original disk 800. After a reflecting film is formed on each substrate 809, the two disk-like substrates are laminated together. Thereafter a
completed disk 809 is made. Recorded in the BCA areas 814 of completed disks 809 are different IDs 815 and/or first cipher keys 816 (public keys) and/or second cipher keys 817 (public keys) and second computer connection addresses 818 so as to make
disks 801 each with a BCA. The disks 801 are distributed to users.
The contents of these disks have been enciphered. Therefore, in order to reproduce the contents of each of the disks, it is necessary to get a password from a password issue center, an electronic shop or a mall, by paying a charge. That
procedure will be described next.
In a user's first computer 909, if a reproducer 819 reproduces a distributed disk 801 with a BCA, a BCA reproduction part 820 including a PE-RZ demodulation part reproduces the data of the ID 815, first cipher key 816, second cipher key 817
and/or connection address 818. In order to get a password, the connection address 818 of the second computer 821a, which is the server of a password issue center 821, is accessed through a communication part 822 via the Internet or another network 823,
and the ID is transmitted to the second computer 821a.
Here, the cryptocommunication procedure will be described. The second computer 821a receives the ID 815 from the user's reproducer 819. Then, the second computer or server 821a of the password issue center 821, which is called a `mall` or an
`electronic shop` has a cipher key database 824. This database contains a table of the secret keys which are the decoding keys corresponding to the disks' own IDs or the first cipher keys 816 of the IDs, that is the first decoding keys 825 and the IDs.
The server can therefore search for the first decoding key 825 based on the received ID. Thus cryptocommunication is completed from the first computer to the second computer 821a. In this case, if the first cipher key and first decoding key are common
keys of a common key cipher, not of an public key cipher, they are the same key.
If the user wants to use part of the enciphered contents stored on the disk 801, which may be 1,000 in number, for example, the content number 826 of which is `n`, the user sends to the second computer 821a the cipher which is the content number
826, that is, `n` enciphered with the public key which is the first cipher key 816 by the first cipher encoder 827 composed of public key cipher functions. The second computer 821a searches for the first decoding key 825 for decoding this cipher as
stated above. It is therefore possible securely to convert this cipher into plaintext. Thus, the cipher protects the privacy of the user's order data.
In this case, a signature may be made by means of the secret key of the public key cipher as the first cipher key 816. This method is called `digital signature`. For a detailed explanation of the operation of `digital signature`, see, for
example, `Digital Signature of E-Mail Security by Bruce Schneider 1995`.
Back to the cryptocommunication, the cipher is sent through the communication part 822 and network 823 to the first cipher decoder 827 of the password issue center 821. Thus the first cipher decoder 827 decodes the cipher by means of the first
pair cipher key 825 pairing with the first cipher key 816.
In this case, because only the one disk has the public key, it is possible to reject invalid orders from third parties' disks. In other words, because each disk can be certified, it is possible to certify the user who owns the disk. It is thus
certified that the content number `n` represents a particular individual's order. It is therefore possible to exclude invalid orders of third parties.
If the public key 816 is secret, this method can technically be used to send a credit card number, or other accounting data which requires high security. Generally shops called `malls` however, do not settle users' accounting data
electronically, because there is no guarantee of security. Only the accounting centers 828 of credit card companies, banks and the like can deal with users' financial data. Presently, security standards such as secure electronic transaction (SET) are
being unified, so it is probably that Rivest, Shamir and Adleman (RSA) 1024 bit public key ciphers will be used and the encipherment of financial data will be possible.
Next, the accounting data cryptocommunication procedure of the present invention will be shown. First, by using the second cipher key 817 of the public key cipher reproduced by the BCA reproduction part 820, the second cipher encoder 831 ciphers
the accounting data 830 such as an individual's credit card number with a public key system cipher such as RSA. The enciphered data is sent from the communication part 822 through the second computer 821 to the cipher decoder 832 of the third computer
828. In this case, if there is a need for digital signature, the secret key 829 is used as the second cipher key 817.
Similar to the procedure for the cipher key of the second computer 821a of the password issue center 821, it is possible to search the cipher key database 824a for the second decoding key 829 corresponding to the ID or the second cipher key 817.
By using this decoding key 829, the second cipher decoder 832 can decode the enciphered accounting data.
If a digital signature is made by the second cipher encoder 831 with the secret key 829, the user's signature can be confirmed in the second cipher decoder 832. The accounting center 828 can thus get the user's credit card number, bank card
number, bank password, or other accounting data safely even via the Internet. In open networks such as the Internet, security comes into question. By means of this system, however, it is possible to make cryptocommunication or certification without
fault, because the cipher key (public key) for cryptocommunication or the secret key for digital signature has been recorded in the BCA. It is therefore possible to prevent third parties' unauthorized accounting and orders. In addition, because it is
possible to use various public keys for different disks, that is, different users, the confidentiality of communication is improved, and the possibility of users' accounting data leaking to third parties is reduced.
Referring back to FIG. 6, the procedure for issuing a password and the procedure for unlatching with a password will be explained. The password issue center 821 includes a password generation part 834 with an operation expression of public key
ciphers etc. Part 834 is accessed automatically, and merely by distributing disks with cipher keys recorded in the BCAs, security is possible for distribution of commodities by releasing the ciphers of contents, certification and keeping secret purchase
of goods, certification and keeping secret when accounts are settled, and the like. Therefore, the method of cryptocommunication of the present invention can, without lowering security, omit and rationalize the conventional operations of using IC cards,
floppy disks and/or letters to distribute IDs and/or cipher keys to users. This is a great advantage. Furthermore, a URL, which is an Internet connection address, is not fixed, but changeable. The URL is recorded in the original disk, and may be
accessed. It is, however, not efficient from the points of view of time and cost to vary the original disk when a URL change is made. By having recorded the changed URL in the BCA, and connecting the BCA connection address 931 instead of the connection
address of the original disk only if the connection address 931 is reproduced from the BCA, it is possible to access the changed address 931 without preparing a new original disk.
FIG. 6 shows a case where the first key of the public key and the second key of the public key have been recorded in the BCA.
FIG. 8 shows two diagrams, in one of which the first cipher key 816 of the public key and the third decoding key 817a of the secret key have been
recorded in the BCA. In the other diagram, a cipher key is produced for cryptocommunication. Because the procedure is similar to that of FIG. 6, only different points will be described. First, in a press factory, the first cipher key 816 and
third decoding key 817a are recorded in the BCA. The third decoding key 817a is used to receive the cipher
In this case, if the second timing data 835b of the clock 836b does not coincide with the first timing data 838 of the password, the cipher is not correctly decoded and therefore not reproduced. If timing data is used, it can be applied to
time-limit type rental systems, so that a movie can be reproduced for only three days during a rental period.
While FIG. 6 shows the procedure in a block diagram, the flowcharts of the procedure will be explained later with references to FIGS. 16-23.
Next, the system for the cipher key will be described. By putting, as shown in FIG. 7a, both the first cipher key 816 and second cipher key 817 in the BCA, it is possible to provide two securities, for a commodity deal with a shopping mall and
an account settlement with an `accounting center`.
In this case, with respect to the security with an accounting center, it is planned to unify standards such as SET, so that an RSA 1024, that is 128 byte cipher key, will be stored in the second cipher key area 817a. Then, because the BCA has
only 188 bytes, only 60 bytes remain for the cipher key for dealing with a shopping mall. An elliptic function system public key cipher is a cipher function which is 20 bytes in magnitude and which has a security level equal to that of 128 bytes of RSA
1024.
An elliptic function is used in the first cipher key area 816a of the present invention. An elliptic function can obtain 20 byte security, which is equivalent to RSA 1024. Therefore, by using an elliptic function, it is possible to store both
the first cipher key 816 and second cipher key 817 in the 188 byte BCA area.
By applying a BCA to an optical ROM disk, as stated before, it is possible to record a disk's own ID number, the first and second cipher keys, and a connection address. In this case, if the Internet is used, a mall generates a password in the
basis of three data fields, namely, the ID, the content number which the user wants to unlatch, and the time data representing the period of use allowed. The generated password is sent to the first computer 909. In the simplest structure example, the
second computer enciphers with the public key for the public key cipher the data which is a mix of the decoding key disk ID for releasing the cipher of the `1- n`th content and the timing data, prepares at the password generation part 834 the `1- n`th
password 834a which is a mix of secret keys for unlatching the enciphered data, and sends this password 834a to the first computer 909. The first computer 909 receives the `1- n`th password, and decodes with the secret key the mixed keys of the disk ID,
the timing data and the `1- n`th content. Here, the password operation part 836 checks the ID 835a of the BCA reproduced from the disk, the present second timing data 835b, the allowed ID 833a and the first timing data 833, and operates to determine if
they coincide. If they do coincide, they are allowed. The `1- n`th decoding key 836a is output to the cipher decoder 837. The cipher 837a of the `1- n`th content is decoded. The `1- n`th content 838 then is output. The period of output is limited to
the time during which the first timing data 833 and second timing data 835b coincide. The password operation part 836 of the first computer 909 computes three data fields, which are the ID, the password 835 and the timing data from the clock 836b
representing the present time. If the ID and timing data are correct, the correct decoding key is output as the result of the computation. Therefore, the cipher decoder 837 decodes or descrambles the `1- n`th cipher, outputting the plaintext data of
the `1- n`th content 838, or a descrambled picture signal or audio signal. enciphered with the public key from an accounting center. In this case, the reception security is improved.
First, with reference to FIG. 8, a more specific example of cryptocommunication where a cipher key is generated will be described. Because the first cipher key 816 is a public key, it is necessary to record the third decoding key 817a for
reception in the BCA. But the BCA has a small capacity. In addition, the public key needs processing time. Therefore, in FIG. 8, the cipher key generation part 838a of the first computer 836 generates a pair of a cipher key and a decoding key for the
public key or a common key by means of a random number generator or the like. An example of the common key will be described. A common key K 838 is enciphered with the first cipher key 816 and first cipher encoder 842, and sent to the second computer
821a. The second computer uses the main decoding key 844 to convert this cipher into plaintext by means of the main cipher decoder 843, obtaining a common key K 838a. Because both have the common key K, it is possible to make cryptocommunication from a
shop to a user, that is, from the second computer 821a to the first computer 836 by delivering the common key K to the second cipher encoder 842a and second cipher decoder 847a. Naturally, it is also possible to make cryptocommunication from the user to
the shop, that is, from the first computer 836 to the second computer 821a by delivering the common key K to the second cipher encoder 827a and second cipher decoder 845a. The effects of the method of recording in the BCA the first cipher key which is a
public key and generating a cipher key will be stated. First, it is necessary only to record the first cipher key, so that the recording of the decoding key can be omitted. Therefore, the small capacity of the BCA is not reduced. Second, because the
decoding key is recorded in the BCA, the security is improved. The common key may be changed each time.
Because of the short operation time, the processing time is short. In this case, if the cipher key generation part 838a has generated a pair of a cipher key and a decoding key of a public key cipher, not a common key, it is possible to make the
security higher than that with the common key, though the processing time is longer, by cryptically sending the cipher key to the second computer 821a, using this key as the cipher key of the second cipher encoder 842a, and using the decoding key as the
decoding key of the second cipher decoder 847. If the performance of the processing CPU is high, it is preferable that the public key be used. If a new public key is generated, only the public key for the first cipher key is recorded in the BCA, so
that no problems of security arise. No capacity of the BCA is consumed either. In addition, because it is not necessary to change the cipher key, maintenance is easy.
This time, if the common key K 838 is defined at the second computer 821a of the password issue center 821, the common key is enciphered with the third cipher key 839 by the third cipher encoder 840, and sent to the personal computer 836. By
using the third decoding key 837 which is the secret key reproduced from the BCA, the third cipher decoder 841 of the personal computer 836 makes a translation into plaintext to obtain a common key K 838b. In this case, because only this user has the
third decoding key 817a which is the secret key, it is possible to prevent the contents of communication from the center to the user from leaking to third parties. The format of this case is shown in FIG. 7b. If an elliptic function is used, the third
decoding key 839b may by 20 bytes, and can therefore be stored in the BCA.
FIG. 9 shows a system for reducing the costs of preparing an original disk by using a BCA in an encipherment disk.
If there is a number `n` of, for example, 1,000 plaintext contents 850, the cipher encoder 852 enciphers them with the first to the `m`th cipher keys 851, respectively. The ciphered first to the `m`th contents 853, the decoding program 854a for
the first to `m`th contents, and the second cipher decoder 861a, which is the program for decoding the second cipher, are recorded as pits in an original disk and then molded into a substrate, and a reflecting film is formed. Thereafter, two substrates
are laminated together to complete an optical disk 801. The second cipher encoder 860 enciphers the decoding data 854 such as the password for unlatching the `1- n`th, for example, the first content, and the decoding key. Recorded in advance in the BCA
of the first disk are the disk's own identification data, that is, the ID 855 and the second cipher which is the enciphered decoding data. Then, in the reproducer, the second cipher is reproduced from the BCA reproduction part 820. The second cipher
decoder 861 is reproduced from the data reproduction part 862, which reproduces the ordinary recorded data other than the BCA. Therefore, the second cipher decoder 861 is used to decode the second cipher, reproducing the ID 855a and `1- n`th password
854a. The cipher decoder 855b uses the decoding program 854a for the `1- n`th content reproduced from the data reproduction part 862, and uses the ID 855a and password 854a to decode the first cipher, obtaining the plaintext 855c of the `1- n`th content
and the identification data 855a. For a personal computer, the content and ID are recorded on the hard disk 863. This ID 855a checks to determine if there is no same ID on a network when the program has started, and the ID 855a actuates the network
protection. It is therefore possible to prevent the software from being illegally installed. This is yet another advantage of the present invention. For example, if 1,000 enciphered contents are stored and decoding data such as a password
corresponding to a particular software applications are recorded on an original disk, this is equivalent in substance to the preparation of an optical ROM disk for a particular content. It is possible to obtain with one original disk the same effect as
in the case where original disks for 1,000 kinds of software are cut. It is therefore possible to reduce the costs and time or labor for preparing an original disk.
Described with reference to FIG. 10 is the procedure for enciphering contents with a BCA when recording them on a RAM disk. First, the BCA reproduction part 820 reproduces the BCA data from the RAM disk 856, outputs an ID 857, and sends it
through the interfaces 858a and 858b and the network to the encipherment part 859. The cipher encoder 861 of the encipherment part 859 enciphers contents 860 or scrambles picture and sound signals by means of a key including the ID 857. The enciphered
contents are sent to the recorder/reproducer, where the recording circuit 862 records them on the RAM disk 856.
Next, when this signal is reproduced, the data reproduction part 865 demodulates the main data to reproduce the enciphered signal, and the cipher decoder 863 decodes the reproduced signal. The BCA reproduction part 820 reproduces data containing
the ID 857 from the BCA area of the ram disk 856. The reproduced data is sent as part of the key to the cipher decoder 863. If normally copied, the cipher key recorded in the RAM disk is a normal disk ID. The RAM disk ID, also, is a normal disk ID.
Therefore, the cipher is decoded or descrambled to output the plaintext 864 of the `1- n`th content. For a graphic data, for example, the MPEG signal is extended to obtain a picture signal.
In this case, the disk ID is the key for encipherment. Because each disk is unique, it can be copied on only one RAM disk.
If a disk ID is copied from a normal RAM disk to another RAM disk, ID1 which is the original normal disk ID differs from ID2 which is the disk ID of the other, unauthorized, RAM disk. If the BCA of the unauthorized RAM disk is reproduced, ID2 is
reproduced. The contents are ciphered with ID1, however, so that, even if unlatching is attempted with ID2 at the cipher decoder 863, the cipher is not decoded because the key differs. Thus, the signal of the illegally copied RAM disk is not output, so
that the copyright is protected. The present invention uses a disk ID system. Therefore, by reproducing with any drive the normal RAM disk copied normally only once, it is possible to unlatch the cipher. The encipherment part 859 may, in place of the
center, be an IC card with a cipher encoder.
with reference to the block diagram of FIG. 11 and the flowchart of FIG. 12, the method of preventing copying will be described. At Step 877a, the installation program is actuated. At Step 877b, the BCA reproduction part 820 outputs the ID of
the auxiliary data from the laminated optical disk 801. At Step 877d, the data reproduction part 865 reproduces the contents and network check software 870 from the main data. The contents and the ID 857 are recorded on the HDD 872. At Step 877c, the
ID 857 is encoded with a particular secret cipher so as not to be altered illegally, and is recorded as a soft ID in the HDD 857. Thus, the soft ID 873 is recorded together with the contents on the HDD 872 of a personal computer 876. Here described is
the case where the program is started at Step 877f of FIG. 12. When the program is started, the procedure goes to Step 877g, where the soft ID 873 of the HDD 872 is reproduced, and the soft ID 873a in the HDD 872a of another personal computer 876a on a
network 876 is checked through the interface 875. At Step 877h, a check is made to judge if the soft ID 873a of the other personal computer and the soft ID 873 are the same number. If so, the procedure goes to Step 877j, where the start of the program
of the personal computer 876 is stopped or a warning message is displayed on the screen.
If the soft ID 873a of the other personal computer and the soft ID 873 are different, the contents are not installed in the plurality of the computers on the network. It is therefore decided that there are no illegal copies. Then the procedure
goes to Step 877k, where the start of the program is permitted. In this case, the soft ID 873 may be sent to other personal computers through the network. This personal computer can detect illegal installation by checking duplication of the soft IDs of
the personal computers. If there is illegal installation, a warning message is sent to the appropriate personal computer/s.
Thus, by recording the ID in the BCA, and recording the network check program in the pit recording area, it is possible to prevent multiple installation of the software of the same ID on the same network. In this way, simple protection from
illegal copies is realized.
By, as shown in FIG. 13a, applying a write (writing) layer 850 of white material, on which characters or the like can be written, it is possible to not only print characters and write a password or the like with a pen, but also prevent the
substrates of the optical disk from being damaged because the write layer 850 thickens. The disk ID 815, which is part of the BCA data 849 recorded by trimming in the BCA area 801a above the write layer 850, is translated into plaintext. The plaintext
is converted into alphanumeric characters 851. By printing the characters 851 and general bar code 852, it is possible for the store and/or user to confirm and/or check the ID with a POS bar code reader and/or visually, without reading the BCA with a
reproducer. The visible ID is not necessary if the user informs the center of the ID through a personal computer. If, however, the user communicates the ID aurally by telephone to the center, it is possible to inform the center of the ID without
inserting the disk in a personal computer, by printing the ID identical with the BCA ID in visible form on the disk, because the user can visually read the ID. With reference to the flowchart of FIG. 13c, the steps for making an optical disk will be
explained. At Step 853d, disks are molded from an original disk, and substrates in which pits have been recorded are made. At Step 853e, aluminum reflection films are made. At Step 853f, two disk substrates are laminated with an adhesive so that a DVD
disk or the like is completed. At Step 853g, a label is printed by screen printing on one side of each disk. At this step, the original disk's own identification data is recorded in the form of a bar code. At Step 853h, an ID and/or other
identification information is printed in the format of a bar code for POS on each disk by an ink jet bar code printer or a thermal-transcription bar code printer or the like. At Step 853i, the bar code is read by a bar code reader. At Step 853j, a BCA
data corresponding to the identification data is recorded in the second recording area of the disk. According to this method of manufacturing, the BCA data is recorded after all the steps including the POS bar code and excluding the BCA are finished and
then the disk identification data is confirmed. The BCA can be read only by reproducing the disk, but the POS bar code, which is low in density, can be read by a commercial bar code reader. The disk ID can be discriminated at every step in the factory. By recording the disk ID in the form of a POS bar code before the BCA trimming, it is possible to almost completely prevent the BCA and the POS bar code from being illegally recorded.
The method of using a BCA will be stated by which secondary recording and tertiary recording, too, can be made by the BCA method. As shown at Process 2 in FIG. 15, a software maker can also secondarily record a
pirated edition prevention mark and a check cipher. At Process 2, disks 944b may be made in which different ID numbers and/or cipher keys for secret communication with users have been recorded. It is possible to replay the disks 944c and 944d
without entering the passwords.
For another application, at Process 3, an enciphered or scrambled MPEG picture signal and/or other data is recorded on a disk 994e. The operation of the MPEG scramble will not be explained in detail. At Process 4, the software company makes a
disk 844f in which a sub-public key for decoding the ID number and the scramble release data have been BCA-recorded secondarily. It is not possible to replay this disk solely. At Process 5, the selling store, after receiving the money for the disk,
makes a password with the sub-secret key paired with the sub-public key, and records it tertiarily on the disk. Alternatively, a receipt on which the password has been printed is given to the user. Thereafter, the password has been recorded in the disk
844g, so that the user can replay it. This method prevents a disk not paid for from being replayed normally, even if the disk is shoplifted, because the scramble of the image is not released. As a result, shoplifting renders a useless product and thus
decreases.
If a password is BCA-recorded permanently in a rental video store or another store, a shoplifted disk can be used. In this case, as shown at Process 6, the BCA is read by a POS bar code reader in the store. A password for releasing the scramble
is issued at Step 951g, printed on the receipt at Step 951i, and handed to the customer at Step 951j. The customer enters, at Step 951k, the password on the receipt in a player with numeric keys at his/her house. At Step 951p, the disk is replayed for
a predetermined number of days. If a user rents a disk, given a password for only part of the software in the disk, and when he/she wants to view other part of the software, he/she can replay it by being informed of the password for this part by
telephone at Step 951u, and entering the password in Step 951k. A rental video store has been shown as an example. When a piece of enciphered software for a personal computer is sold at a personal computer software store, the password may be printed by
a POS terminal and handed to the buyer.
The operations of Processes 5 and 6 in FIG. 15 at a selling or rental store will be explained in more detail with reference to FIG. 14. A selling store receives an enciphered and/or scrambled disk 944f from the software maker. After the store
confirms its receipt of money from a user, it sends from its bar code recorder 945 the ID number of the disk 944f and the data on the sub-public key via its POS terminal 946 to the password issue center 952. For a small-scale system, the password issue
center, that is, the system including the sub-secret key of the sub-public key may exist in the POS terminal. The password issue center inputs the disk ID number and the time data at Step 951q, computes them at Step 951s, enciphers them with the
sub-secret key at Step 951t, issues a password at Step 951g, and sends it through the network 948 and POS terminal 846 to the BCA bar code recorder 945. Then the recorded disk 944g is handed to the customer. The disk 944g can be replayed as it is.
For rental stores and personal computer software stores, ROM disks 944f the ciphers and/or scrambles of which have not been released are displayed in stores. If a customer designates a particular ROM disk 944f, the bar code of the reflection
layer by the non-reflection part 915 of the disk 944f is read, so that the disk ID number is read, by a person holding a circular bar code reader 950 with an integrated rotary optical head 953 for spirally scanning, and pressing it on the center of disk
900 in a transparent case. By printing the commodity bar code of the disk ID as shown at 852 in FIG. 13, it is possible to read the code with an ordinary POS terminal bar code reader. Alternatively, the pressed circular bar code recorded in advance on
the original disk may be read. These data including the disk ID are processed by the POS terminal 946. The charge is settled by credit card. The password issue center issues, at Step 951g, a password associated with the ID number as stated above. For
rental use, a password is made by enciphering the disk ID number with date data added as used at Step 951r in order to limit the number of days for which the disk can be replayed. For this password, the disk can operate on only particular days. It is
therefore possible to set a rental period, which may be three days, for instance, in the password.
The thus issued password for de | | |
