A copy prevention method and apparatus for a digital video system is disclosed including the steps of: (a) adding a header area of a header start code and key field to a reproduced bit stream: (b) decrypting and transmitting the bit stream to which the header area is added: (c) detecting a key field of the decrypted and transmitted bit stream and detecting copy prevention information; and (d) encrypting the bit stream according to information detected from stop (c) and recording it an tape.
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0. 35. An apparatus for copy prevention, comprising:
a receiving device configured to receive a digital data stream;
a detecting device configured to detect an encryption key from the received digital data stream, and to detect copy prevention information from the received digital data stream, the encryption key for decrypting digital content from the received digital data stream and the copy prevention information for indicating whether or not a copy of the digital content of the digital data stream is permitted; and
a controller configured to control a copy protection function for the digital content based on the detected copy prevention information and key information,
wherein said controller is configured to control the copy protection function such that the digital content is not copied, when the copy prevention information indicates that a copy is not permitted, and
wherein said controller is configured to identify whether the digital content is encrypted based on classification information detected from the digital data stream, and control to decrypt the digital content based on the key information if the digital data stream is encrypted.
0. 32. A copy protection method for a digital data system, the method comprising:
detecting, via a decryption device included in the digital data system, key information and copy prevention information from received digital data or from a signal reproduced from a digital recording medium, the key information for decrypting digital content from the received digital data or from the signal, the copy prevention information for indicating at least whether or not a copy of the digital content is permitted; and
controlling, via a controller within the digital data system, a copy protection function for the digital content based on the copy prevention information and the key information,
wherein said controlling step controls the copy protection function such that the digital content is not copied, when the copy prevention information indicates that a copy is not permitted, and
wherein said copy protection function includes identifying whether the digital content is encrypted based on classification information detected from the digital data, and decrypting, via the decryption device according to control of the controller, the digital content based on the key information if the digital content is encrypted.
0. 1. A copy prevention method for a digital video system comprising the steps of:
(a) receiving a digital data stream reproduced from a digital medium;
(b) detecting an encryption key, which is a portion of said received digital data stream;
(c) decrypting said encryption key using key information;
(d) decrypting said received digital data stream based on said decrypted encryption key; and
(e) transmitting said decrypted digital data stream to at least one of a monitor and a digital recorder.
0. 2. A copy prevention method for a digital video system as claimed in
0. 3. A copy prevention method for a digital video system as claimed in
0. 4. A copy prevention apparatus for a digital video system comprising:
receiving means for receiving a digital data stream reproduced from a digital medium;
a key detector to detect an encryption key, which is a portion of said received digital data stream;
a decryption unit to decrypt said encryption key using key information and to decrypt said received digital data stream based on said decrypted encryption key; and
a controller to control transmission of said decrypted digital data stream to at least one of a monitor and a digital recorder.
0. 5. A copy prevention apparatus for a digital video system as claimed in
0. 6. A copy prevention apparatus for a digital video system as claimed in
0. 7. A copy prevention method for a digital video system comprising the steps of:
(a) receiving a digital data stream reproduced from a digital medium;
(b) detecting an encryption key, which is a portion of said received digital data stream;
(c) decrypting said encryption key using key information;
(d) decrypting said received digital data stream based on said decrypted encryption key.
0. 8. A copy prevention method for a digital video system as claimed in
0. 9. A copy prevention method for a digital video system as claimed in
0. 10. A copy prevention apparatus for a digital video system comprising:
receiving means for receiving a digital data stream reproduced from a digital medium;
a key detector to detect an encryption key, which is a portion of said received digital data stream;
a decryption unit to decrypt said encryption key using key information and to decrypt said received digital data stream based on said decrypted encryption key.
0. 11. A copy prevention apparatus for a digital video system as claimed in
0. 12. A copy prevention apparatus for a digital video system as claimed in
0. 13. A copy prevention method for a digital video system comprising the steps of:
(a) receiving a digital data stream reproduced from a digital medium;
(b) detecting an encryption key, which is a portion of said received digital data stream;
(c) decrypting said encryption key using predetermined key information;
(d) decrypting said received digital data stream based on said decrypted encryption key.
0. 14. A copy prevention method for a digital video system as claimed in
0. 15. A copy prevention apparatus for a digital video system comprising:
receiving means for receiving a digital data stream reproduced from a digital medium;
a key detector to detect an encryption key, which is a portion of said received digital data stream;
a decryption unit to decrypt said encryption key using predetermined key information and to decrypt said received digital data stream based on said decrypted encryption key.
0. 16. A copy prevention apparatus for a digital video system as claimed in
0. 17. A copy prevention method for a digital data system, comprising the steps of:
(a) receiving first key information;
(b) encrypting second key information using said first key information;
(c) encrypting digital data streams using said second key information; and
(d) recording at least said encrypted second key information and said encrypted digital data streams on a digital medium.
0. 18. The method of
0. 19. The method of
0. 20. A copy prevention apparatus for a digital data system, comprising the steps of:
an encryption unit receiving first key information, encrypting second key information using said first key information, and encrypting digital data streams using said second key information; and
a controller controlling recording of at least said encrypted second key information and said encrypted digital data streams on a digital medium.
0. 21. The apparatus of
0. 22. The apparatus of
0. 23. A recording medium having a data structure for controlling operation of copy prevention function in a digital data processing device, comprising:
a digital data area storing digital data encrypted using first key information; and
a key information area storing said first key information encrypted using second key information, said first key information operatively controlling the decryption of said encrypted digital data in a digital data process device.
0. 24. A copy prevention method for a digital data system, comprising:
receiving first key information, said first key information for encrypting digital data;
encrypting said first key information using second information; and
transferring said encrypted first key information.
0. 25. The method of
0. 26. The method of
0. 27. The method of
0. 28. A copy prevention apparatus for a digital data system, comprising:
an encryption unit receiving first key information, said first key information for encrypting digital data, and encrypting said first key information using second key information; and
a controller controlling a transfer of said encrypted first key information.
0. 29. The apparatus of
0. 30. The apparatus of
0. 31. The apparatus of
0. 33. The method of claim 32, wherein said controlling step (b) controls the copy protection function such that the digital content is decrypted only when the key information is detected.
0. 34. The method of claim 32, wherein the copy prevention information includes information indicating a first recording source can copy the digital content onto a first recording medium but a second recording source can then not copy the digital content from the first recording medium to a second different recording medium.
0. 36. The apparatus of claim 35, further comprising:
a decryption device configured to decrypt the digital content based on the encryption key, according to the control of the controller.
0. 37. The apparatus of claim 36, wherein said decryption device is configured to operate on units of predetermined blocks of the digital content, according to the control of the controller.
0. 38. The apparatus of claim 35, wherein the encryption key is predetermined by the digital content.
0. 39. The apparatus of claim 35, wherein the copy prevention information includes information indicating a first recording source can copy the digital content onto a first recording medium but a second recording source can then not copy the digital content from the first recording medium to a second different recording medium.
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This is Notice: More than one reissue applications have been filed for the reissue of U.S. Pat. No. 6,347,144. The reissue applications are application Ser. Nos. 10/737,671, 10/737,672 (now U.S. Pat. No. Re. 39,319), Ser. No. 11/040,606 (now U.S. Pat. No. Re. 41,074), and Ser. No. 11/040,607 (the present application) which are all reissues of U.S. Pat. No. 6,347,144; Ser. Nos. 10/981,797, 10/737,672, 10/909,248 and 10/981,798 which are all divisionals of Ser. No. 10/737,672; Ser. No. 12/139,161 which is a continuation of Ser. No. 10/909,248; and Ser. Nos. 12/405,011 and 12/405,053 which are both divisionals of Ser. No. 10/981,798. U.S. Pat. No. 6,347,144 resulted from application Ser. No. 09/497,465, which is a continuation of application Ser. No. 09/053,288, filed Apr. 1, 1998, now U.S. Pat. No. 6,028,932, which is a continuation of Ser. No. 08/562,042, filed Nov. 22, 1995, now U.S. Pat. No. 5,761,302, issued Jun. 2, 1998.
The present invention relates to a copy prevention technology for a digital video system, and more particularly, to a copy prevention method and apparatus for a digital VCR to which encryption is introduced to display a picture only in a VCR internally containing a corresponding encryption code, thereby preventing tape from being copied.
General copy prevention methods for analog VCR are presented in U.S. Pat. Nos. 4,819,098, 4,571,642 and 4,577,216.
First, U.S. Pat. NO. 4,819,098 discloses a method in which an interference signal is inserted into a video waveform in an automatic gain control circuit (AGC) of a VCR. Here, the inserted signal does not affect the AGC of its monitor but has the AGC of the VCR record an accurate level of signal on a video tape.
In U.S. Pat. No. 4,571,642, there is presented a method in which a phase noise or other corrected signal is inserted into the chrome burst of a video waveform.
However, all the conventional technologies insert a distributing signal to an analog signal using the difference between a circuit of a monitor and a corresponding circuit of a VCR. Some VCRs may perform copy normally despite of copy prevention. Some monitors cannot display images of the original video tape. A conventional copy prevention introduced to an analog VCR system is hard to be applied to digital storage media (DSM).
Specifically, in a satellite receiver or high-definition TV decoder, as shown in
The PES header contains a PES header flag area of 14 bits which is a field for DSM such as digital VCR, and a PES header field having a variable length. The PES header flag area includes 1-bit copyright (CR) flag, 1-bit original-or-copy (OC) flag, 2-bit PD flag, 1-bit TM flag, and 1-bit AC flag.
The PES header field varies in length, and part thereof is set by the PC, TM and AC flags. A PTS/DTS area is not present if the value of the PD flag is “00”. It is 40 bits if the value “10”. If the value is “11”, the area is 80 bits. A DSM trick mode field is not present if the TM flag is “0”. If the flag is “1”, the field is 8 bits. An additional copy information field is 8 bits if the AC flag is “1”.
When recording is carried out by the satellite receiver or high-definition TV decoder and compressed video data is encoded in encoder 101, it is converted into a packet form in packet processing portion 122 as shown in
When the outputs of packet processing portions 102 and 104 are multiplexed in transmission multiplexer 105, a fixed transmission stream shown in
This public-key encryption system has all users U hold unique encryption algorithm EPKU and description algorithm DPKU. Here, encryption algorithm EPKU for the public-key is opened as a public-key to key supply portion 107. Decryption algorithm DPKU for secret key is kept in secret. The characteristics of EPPKU and DPKU are as follows.
First, with respect to all users U and message m transmitted, DPKU(EPKU(m))=m.
Second, encryption algorithm EPKU and decryption algorithm DPKU do not require complicated calculation.
Third, it is impossible to find DPK″U satisfying DPK″U(EPKU(m))=m from encryption algorithm EPKU.
In the encryption system having the above characteristics, as shown in
Key decrypter 108 receiving the key information from key supply portion 107 outputs an algorithm DPKB corresponding to encryption algorithm EPKB, decrypter 109 decrypts (DPKB(c))=m) the output of encrypter 106 with decryption algorithm DPKB, and then transmits user B. In other words, only user B can decrypt decryption algorithm DPKB corresponding to encryption algorithm EPKB.
A concept developed from the public-key encryption is presented in U.S. Pat. No. 4,405,829. This public-key encryption system is called RSA system. A method in which the RSA public-key encryption is efficiently calculated via batch processing is presented in U.S. Pat. No. 4,964,164.
However, this public-key encryption is inappropriate for high-velocity encryption. A CA system is to present illegal view. However, there is no method of protecting a program distributed through a digital storage medium such as digital VCR.
Therefore, it is an object of the present invention to an illegal copy prevention method and apparatus for a digital video system in which, in copy tape, encrypted key information is transmitted and recorded so that a copied tape is reproducible only in a VCR having a corresponding encrypted key information, thereby prevented copy.
To accomplish the object of the present invention, there is provided a copy prevention method for a digital video system comprising the steps of: (a) adding a header area of a header start code and key field to a reproduced bit stream; (b) decrypting and transmitting the bit stream to which the header area is added; (c) detecting a key field of the decrypted and transmitted bit stream and detecting copy prevention information; and (d) encrypting the bit stream according to information detected from step (c) and recording it on tape.
For the object of the present invention, there is provided a copy prevention apparatus for a digital video system comprising: a reproduction block for adding key information to a reproduced bit stream, and decrypting and transmitting it; and a recording block for searching key information of the bit stream transmitted from the reproduction block is extract copy prevention information, and encrypting and recording the bit stream according to the extracted copy prevention information.
The reproduction block comprises: reproduction means for reproducing data recorded on tape; key insertion means for adding key information to the bit stream of the reproduction means; and decryption means for decrypting the output of the key insertion means and transmitting it to a recording-side VCR.
The recording block comprises: key detecting/correcting means for detecting key information from the transmitted bit stream of a reproducing-side VCR: copy prevention information detecting means for searching the key information detected from the key detecting/correcting means to detect copy prevention information; encrypting means for encrypting the bit stream according the copy prevention information of the copy prevention information detecting means; and recording means for recording the bit stream encrypted in the encrypting means.
The copy prevention information detecting means comprises: a PES header detecting portion for detecting a PES header from parallel data output from the key detecting/correcting means; and a copy prevention information extractor enabled by a PES header detection signal of the PES header detecting portion to detect an additional copy information field.
Hereinafter, a preferred embodiment of the present invention will be described below with reference to the attached drawings.
Referring to
As shown in
Referring to
As shown in
The operation and effect of the present invention will be explained below. Generally, in case of reproducing or copy recording data on tapa, connections between systems are made as shown in
With those connections, an MPEG bit stream reproduced from VCR A is input to a satellite receiver or high-definition TV so that it cannot be recognized whether the stream is displayed on a screen or input to VCR B and recorded on another video tape.
For this reason, according to the present invention, in case that the bit stream reproduced from VCR A is copied from VCR B, information on copy prevention is transmitted to VCR B from VCR A. VCR B analyzes this information which is recorded with the bit stream.
Here, the insertion position of the copy prevention information contained in a GA bit stream is very limited because it must not affect decoding of the decoder of the satellite receiver or high-definition TV so that an image is displayed normally on a monitor. The copy prevention information may be inserted into the front end of the MPEG bit stream or inside the PES header.
When the MPEG bit stream is decoded in units or group of picture (GOP), the respective GOPs are classified by their cop start codes. This is useful in transmitting initialization data to a recording-side VCR because decoding is never affected even when a slight amount of data is added to the front end of the MPEG bit stream.
The case of inserting the copy prevention information into the PES header is useful in repeated transmission of information because copy prevention of a recording medium such as DSM is decided using CR and OC flaps of the PES header and additional copy information field. In this case, there are a variety of copy preventing methods.
First, when a mode of “No Copy” is detected from the additional copy information field of the PES header, VCR B is not able to enter its recording mode.
Second, when a mode of “Copy Permitted” is detected in order to implement a copy prevention such as DAT mode, VCR B records but “No Copy” mode is recorded in the additional copy information field to interrupt recopying from a copying tape. This means that a secondary source, but a third source tape cannot.
Third, for “Back-up Copy”, tape B copied from VCR B is reproducible normally only in VCR A. According to this method, reproducing-side VCR A encrypts the bit stream with its own inherent key and records it on tape so that only reproducing-side VCR A decrypts the MPEG bit stream recording on the tape. For every VCR set, a unique key is provided, encrypted by VCR's key and recorded on tape B. However, the VCR set for recording tape B is VCR B and tape B is encrypted by VCR A's key so that VCR A's key needs to be transmitted to VCR B with GA bit stream.
Accordingly, when the key information of VCR A is transmitted as a header in advance prior to the bit stream in the “Back-up Copy”, it is recorded at the front end of tape B, which satisfies the insertion position of the copy prevention information mentioned before.
Here, as shown in
In case of recording the bit stream shown in
Here, a header area added to the front of the MPEG bit stream is formed with a tape header start code, that is, the header identifier code, and a key field for storing key information. In case of encrypting the MPEG bit stream in units of GOP, encryption blocks are classified by the packet start code prefix and stream ID of the PES header. The encryption block is a basic unit of encryption and can change whether encryption is performed in units of the encryption block, and encryption algorithm and key selection. Here, the encryption blocks must not be encrypted until the additional copy information field of the PES header. Encryption is performed until the end of the encryption block after the additional copy information field. The first ‘transmission header’ is not encrypted.
The operation of performing the “back-up Copy” mode by adding the header will be described below.
First, in copying, when recording data of tape A is encrypted, reproducing-side VCR A decrypts it using the key information of the key field so as to make message m. Its key information is added to the header and transmitted in the format of
Recording-side VCR B records the key information transmitted from reproducing-side VCR A on the header of copying tape B and then records the encrypted bit stream. Here, when the key information is transmitted from reproducing side to recording side, for security, a public-key encryption may be employed to the system because the information may be exposed to a pirate.
Such public-key encryption system ensures the secret of data even though the public-key is exposed but cannot be processed in real-time due to a great amount of calculation. Therefore, this system is not improper when the MPEG bit stream is encrypted directly. The “Back-up Copy” can be implemented when the MPEG bit stream is encrypted using a block-cipher algorithm or stream-cipher algorithm such as DES and a key used is encrypted in the public-key encryption.
In this case, every VCR u incorporates encryption algorithm EPKU corresponding to the public-key and decryption algorithm DPKU corresponding to the secret key. Encryption algorithm EPKU takes a power key of VCR u, and decryption algorithm DPKU an internal key of VCR u.
Here, the internal key may be opened to the public. Reproducing-side VCR A transmits the internal key on the key field of the header because another VCR encrypts using the internal key. Recording-side VCR B randomly selects a key Y used in the block-cipher algorithm such as DES and encrypts it with the public-key encryption system using an external key EPKA. The result is recorded on the key field of copying tape B.
Sequentially, the data is divided into encryption blocks and encrypted and recorded in the block-cipher algorithm using key Y. In this method, the bit stream of
When copying tape B is reproduced in reproducing-side VCR A, key Y can be restored by decryption DPKA[EPKA(Y)] in which data is decrypted properly. In other VCRs, key Y cannot be found, which disables the decryption of the bit stream.
As embodiment of the present invention shown in
When playback starts for tape copying, reproducing portion 1 detects data recorded on tape as shown in
When the bit stream of
Copying prevention information detecting portion 5 searches the PES header area to detect the additional copy information field. Here, though a slight amount of information is recorded in the additional copy information field, redundancy is provided in several areas of the bit stream to increase reliability of information transmitted.
Copy prevention information detecting portion 5 extracts the value of AC flag from the PES header flag in order to calculate the position of the additional copy information field because it varies within the PES header. Here, when copy prevention information correcting portion 6 corrects the output of copy prevention information detecting portion 5, encrypting portion 7 performs encryption using the block-cipher algorithm such as DES. Here, copy prevention information correcting portion 6 performs correction while the input data is stored in a RAM. Accordingly, encrypting portion 7 records the encrypted bit stream on tape in recording portion 8. Because the key information of the reproducing-side VCR is added on the copying tape, only a VCR having this key information can reproduce tape normally.
As shown in
PES header detector 10 for detecting the PES header is formed as shown in
Here, packet start code detecting portion 13 searches the bit stream shown in
Meanwhile, stream ID code detector 14 searches the output of second flipflop 12 and detects the stream ID area of the PES header. Then, detection signal is-sid shown in
Here, copy prevention information extractor 20 for detecting the copy prevention information is formed as shown in
D-flipflop 23 is synchronized to the CR flag or the output of D-flipflop 21 shown in
Copy prevention position detector 25 searches the PD, TM and AC flags of the parallel data of PES header detector 10 shown in
D-flipflop 27 synchronized to HIGH output rco of counter 26 holds the additional copy information field from the parallel data of D-flipflop 21 shown in
As described above, in the copy prevention method and apparatus for a digital video system of the present invention, a key information is recorded with a bit stream so that a VCR having the key information reproduces tape normally, thereby preventing illegal copy of tape. In addition, for key information transmission, the public-key encryption is introduced to disable a pirate to release the copy prevention, increasing reliability of copy prevention.
Patent | Priority | Assignee | Title |
8190529, | Jul 30 2002 | Sony Corporation | Information processing system, information communication terminal and method, information processing apparatus and method, recording medium, and program for internet transaction |
9008308, | Feb 08 2012 | Pixelworks, Inc | Container agnostic decryption device and methods for use therewith |
9641322, | Feb 08 2012 | Pixelworks, Inc | Container agnostic decryption device and methods for use therewith |
Patent | Priority | Assignee | Title |
3753228, | |||
4420829, | Jan 08 1981 | Holographic system for the storage of audio, video and computer data | |
4554461, | Dec 24 1982 | Hitachi, Ltd. | Information transmitting apparatus |
4694489, | Dec 22 1983 | Video transmission system | |
4736422, | Jun 30 1983 | Independent Broadcasting Authority | Encrypted broadcast television system |
4796220, | Dec 15 1986 | Pride Software Development Corp. | Method of controlling the copying of software |
4802215, | Jul 23 1983 | Independent Broadcasting Authority | Security system for television signal encryption |
4817140, | Nov 05 1986 | International Business Machines Corp. | Software protection system using a single-key cryptosystem, a hardware-based authorization system and a secure coprocessor |
4890319, | Sep 21 1984 | Scientific-Atlantic, Inc. | Method for controlling copying of protected information transmitted over a communications link |
4916738, | Nov 05 1986 | International Business Machines Corp. | Remote access terminal security |
4924513, | Sep 25 1987 | HEWLETT-PACKARD DEVELOPMENT COMPANY, L P | Apparatus and method for secure transmission of data over an unsecure transmission channel |
4937679, | Aug 11 1986 | Macrovision | Dual deck video recording apparatus having enhanced copy protection and method for providing enhanced copy protection to such a recording apparatus |
4965680, | Jun 30 1987 | Kabushiki Kaisha Toshiba | Apparatus for releasing a restriction on the recording of an information signal on a recording medium |
4975952, | Sep 04 1985 | U. S. Philips Corporation | Method of data communication |
4999806, | Sep 04 1987 | Software distribution system | |
5003590, | Dec 18 1989 | Eidak Corporation | Encoding an optical video disc to inhibit video tape recording |
5014274, | Apr 08 1988 | Victor Company of Japan, Ltd. | Code-error correcting device |
5034981, | Apr 11 1988 | EIDAK CORPORATION, A CORP OF DE | Anti-copying video signal processing |
5034985, | Nov 13 1989 | Pitney Bowes Inc. | Matched mailing system employing address print array recognition |
5054064, | Mar 29 1990 | Verizon Laboratories Inc | Video control system for recorded programs |
5057947, | Feb 10 1988 | MATSUSHITA ELECTRIC INDUSTRIAL CO , LTD , | Recording and reproducing apparatus with limited digital copying |
5058162, | Aug 09 1990 | Hewlett-Packard Company | Method of distributing computer data files |
5073925, | Jul 08 1987 | Matsushita Electric Industrial Co., Ltd. | Method and apparatus for the protection of signal copy |
5109413, | Nov 05 1986 | International Business Machines Corporation | Manipulating rights-to-execute in connection with a software copy protection mechanism |
5134656, | Feb 22 1989 | NAGRA PLUS S A | Pre-payment television system using a memory card associated with a decoder |
5138659, | May 02 1991 | GENERAL INSTRUMENT CORPORATION GIC-4 | Conversion of television signal formats with retention of common control data stream |
5144658, | Nov 24 1989 | Sharp Kabushiki Kaisha | Repeater of digital audio interface signal |
5159633, | Jan 19 1990 | Canon Kabushiki Kaisha | Multimedia network system |
5182680, | Feb 26 1990 | Sony Corporation | Recording control system |
5193176, | Oct 17 1990 | POWERCARD SUPPLY, L C | Computer work saving during power interruption |
5231546, | Feb 10 1988 | Matsushita Electric Industrial Co., Ltd. | Recording and reproducing apparatus with limited digital copying |
5233650, | Mar 03 1989 | Sun Plan Investments Limited | Telephone support device |
5243650, | Mar 23 1990 | Televerket | Method and apparatus for encryption/decryption of digital multisound in television |
5260999, | Jun 28 1991 | HEWLETT-PACKARD DEVELOPMENT COMPANY, L P | Filters in license management system |
5265164, | Oct 31 1991 | INTERNATIONAL BUSINESS MACHINES CORPORATION A CORP OF NEW YORK | Cryptographic facility environment backup/restore and replication in a public key cryptosystem |
5289276, | Jun 19 1992 | General Electric Company | Method and apparatus for conveying compressed video data over a noisy communication channel |
5303294, | Jun 18 1991 | Matsushita Electric Industrial Co., Ltd. | Video theater system and copy preventive method |
5315448, | Mar 18 1993 | Macrovision Corporation | Copy protection for hybrid digital video tape recording and unprotected source material |
5323244, | Sep 24 1992 | Matsushita Electric Industrial Co., Ltd. | Recording and reproducing apparatus |
5377266, | Jul 21 1992 | MATSUSHITA ELECTRIC INDUSTRIAL CO , LTD | Scramble apparatus and descramble apparatus |
5381481, | Aug 04 1993 | Cisco Technology, Inc | Method and apparatus for uniquely encrypting a plurality of services at a transmission site |
5392351, | Mar 16 1992 | Fujitsu Limited | Electronic data protection system |
5406625, | Nov 22 1991 | Sony Corporation | Receiving apparatus and recording method |
5418853, | Jul 24 1992 | Sony Corporation | Apparatus and method for preventing unauthorized copying of video signals |
5442541, | Jul 23 1993 | Xerox Corporation | Enabling features over common communication channel |
5469272, | Mar 05 1991 | Sony Corporation | Digital signal recording and/or reproducing apparatus |
5477276, | Dec 17 1992 | Sony Corporation | Digital signal processing apparatus for achieving fade-in and fade-out effects on digital video signals |
5504816, | Feb 02 1994 | Google Technology Holdings LLC | Method and apparatus for controlling access to digital signals |
5506903, | Apr 06 1993 | Sony Corporation | Digital multiplex transmission system |
5513260, | Jun 29 1994 | Macrovision Corporation | Method and apparatus for copy protection for various recording media |
5530756, | Sep 15 1993 | U S PHILIPS CORPORATION | Television scrambling and descrambling method, and transmitter and receiver using said method |
5546461, | Apr 09 1993 | MATSUSHITA ELECTRIC INDUSTRIAL CO , LTD | Scramble system for use in digital video signal recording and reproducing system or transmission and receiving system, comprising scramble apparatus and descramble apparatus |
5563946, | Apr 25 1994 | ACTIVISION PUBLISHING, INC | Method and apparatus for enabling trial period use of software products: method and apparatus for passing encrypted files between data processing systems |
5574787, | Jul 25 1994 | Macrovision Corporation | Apparatus and method for comprehensive copy protection for video platforms and unprotected source material |
5576843, | Oct 29 1993 | WARNER BROS HOME ENTERTAINMENT INC | System and method for controlling play of multiple dialog audio tracks of a software carrier |
5579120, | Oct 08 1993 | Sony Corporation | Copyright protection for digital signal recording and/or reproduction and recording medium thereof |
5588058, | Mar 31 1993 | U S PHILIPS CORPORATION | Method and device for scrambling and descrambling of a specific television broadcast |
5590306, | Sep 08 1992 | FUJIFILM Corporation | Memory card management system for writing data with usage and recording codes made significant |
5629980, | Nov 23 1994 | CONTENTGUARD HOLDINGS, INC | System for controlling the distribution and use of digital works |
5638513, | Dec 22 1993 | STAMPS COM, INC | Secure software rental system using continuous asynchronous password verification |
5646992, | Sep 23 1993 | MICROSEMI FREQUENCY AND TIME CORPORATION | Assembly, distribution, and use of digital information |
5659613, | Jun 29 1994 | Macrovision Corporation | Method and apparatus for copy protection for various recording media using a video finger print |
5673357, | Feb 15 1994 | Sony Corporation | Video recording, transmitting and reproducing apparatus with concurrent recording and transmitting or multiple dubbing of copy protected video signals |
5689559, | Dec 08 1994 | LG Electronics Inc | Copy prevention method and apparatus of a digital magnetic recording/reproducing system |
5689561, | Oct 06 1995 | Computer-based trading card system and method | |
5703859, | Sep 01 1995 | Sony Corporation | Digital video copy protection system |
5715403, | Nov 23 1994 | CONTENTGUARD HOLDINGS, INC | System for controlling the distribution and use of digital works having attached usage rights where the usage rights are defined by a usage rights grammar |
5757909, | Nov 26 1994 | LG ELECTRONICS, INC | Illegal view and copy protection method in digital video system and controlling method thereof |
5757910, | Apr 06 1993 | LG ELECTRONICS, INC | Apparatus for preventing illegal copying of a digital broadcasting signal |
5761302, | Nov 26 1994 | LG Electronics Inc | Copy prevention method and apparatus for digital video system |
5778064, | Mar 31 1995 | Sony Corporation | Apparatus and method for processing a high definition video signal |
5790664, | Feb 26 1996 | GraphOn Corporation | Automated system for management of licensed software |
5799081, | Sep 18 1995 | LG Electronics Inc. | Illegal view/copy protection method and apparatus for digital broadcasting system |
5832084, | Nov 10 1995 | LG Electronics, Inc. | Recording method of digital magnetic recording medium for copyright protection and variable speed playback |
5862115, | Nov 30 1993 | JVC Kenwood Corporation | Method and apparatus for recording an information signal with scrambling thereof |
5881038, | Feb 27 1994 | Matsushita Electric Industrial Co., Ltd. | Method and apparatus for preventing illegal copy or illegal installation of information of optical recording medium |
5898695, | Mar 29 1995 | Hitachi Maxell, Ltd | Decoder for compressed and multiplexed video and audio data |
5907443, | May 30 1990 | Canon Kabushiki Kaisha | Recording and reproducing apparatus adapted to selectively control the number of copies made |
5910987, | Feb 13 1995 | INTERTRUST TECHNOLOGIES CORP | Systems and methods for secure transaction management and electronic rights protection |
5925127, | Apr 09 1997 | Microsoft Technology Licensing, LLC | Method and system for monitoring the use of rented software |
5956505, | Dec 24 1991 | Pitney Bowes Inc. | Remote activation of software features in a data processing device |
6009401, | Apr 06 1998 | SAFENET DATA SECURITY ISRAEL LTD | Relicensing of electronically purchased software |
6028932, | Nov 26 1994 | LG Electronics Inc. | Copy prevention method and apparatus for digital video system |
6052242, | Jun 07 1989 | Canon Kabushiki Kaisha | Recording apparatus with copy control based on copies made and allowed to be made |
6236971, | Nov 23 1994 | CONTENTGUARD HOLDINGS, INC | System for controlling the distribution and use of digital works using digital tickets |
6430290, | Jan 23 1998 | Koninklijke Philips Electronics N V | Conditional access |
7069250, | Oct 15 2001 | CUFER ASSET LTD L L C | Check based online payment and verification system and method |
7114745, | Dec 10 2002 | TRW Automotive Safety Systems GmbH | Monitoring system for detent connections |
EP267039, | |||
EP498617, | |||
EP519320, | |||
EP580367, | |||
EP581227A2, | |||
EP589459, | |||
JP6070282, | |||
JP6162690, | |||
JP6199288, | |||
JP6339110, | |||
RE33189, | May 09 1988 | Comsat Corporation | Security system for SSTV encryption |
RE36763, | Jul 24 1992 | Sony Corporation | Apparatus and method for preventing unauthorized copying of video signals |
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