Abstract: Video data exploitation by alteration of data is prevented. An extractor 111 extracts valid video data in data 110 and predetermined data in the data. An inserter 114 inserts an arithmetic operation result of the predetermined data by an arithmetic operation unit 113 into the valid video data encrypted by an encryptor 112. An output of the inserter 114 is supplied to an extractor 144 through a transmission path 120. The encrypted valid video data and arithmetic operation resultant data of the arithmetic operation unit 113 are extracted. An arithmetic operation unit 143 executes the same arithmetic operation as that of the arithmetic operation unit 113 to data corresponding to the data used in the arithmetic operation unit 113 from the valid video data decrypted by a decryptor 141 and extracted by an extractor 144. A comparator 145 compares an output of the arithmetic operation unit 143 with an arithmetic operation result extracted from data 140.

Abstract: Video data exploitation by alteration of data is prevented. An extractor 111 extracts valid video data in data 110 and predetermined data in the data. An inserter 114 inserts an arithmetic operation result of the predetermined data by an arithmetic operation unit 113 into the valid video data encrypted by an encryptor 112. An output of the inserter 114 is supplied to an extractor 144 through a transmission path 120. The encrypted valid video data and arithmetic operation resultant data of the arithmetic operation unit 113 are extracted. An arithmetic operation unit 143 executes the same arithmetic operation as that of the arithmetic operation unit 113 to data corresponding to the data used in the arithmetic operation unit 113 from the valid video data decrypted by a decryptor 141 and extracted by an extractor 144. A comparator 145 compares an output of the arithmetic operation unit 143 with an arithmetic operation result extracted from data 140.

Abstract: An encryption apparatus for encrypting input picture data with high secrecy and restoration against an error of encrypted data. An EXOR circuit calculates input picture data and a pseudo random sequence and obtains encrypted data. The obtained encrypted data are held in a first FF circuit. The first FF circuit is reset for each line. Counters count for each line or each frame and are reset for each frame or at the beginning of a program. An encryption device encrypts outputs of a second FF circuit that holds a fixed value, the counters and the first FF circuit with a key and generates a pseudo random sequence. A shift register divides the bit sequence. The EXOR circuit calculates the output of the shift register and the input picture data and obtains encrypted data. Since the encrypted output is fed back, data cannot be stolen using a successive input of the same data. In addition, since an encrypted output that is fed back is reset for each line, the encrypted output can be recovered from an error.

Abstract: Video data exploitation by alteration of data is prevented. An extractor 111 extracts valid video data in data 110 and predetermined data in the data. An inserter 114 inserts an arithmetic operation result of the predetermined data by an arithmetic operation unit 113 into the valid video data encrypted by an encryptor 112. An output of the inserter 114 is supplied to an extractor 144 through a transmission path 120. The encrypted valid video data and arithmetic operation resultant data of the arithmetic operation unit 113 are extracted. An arithmetic operation unit 143 executes the same arithmetic operation as that of the arithmetic operation unit 113 to data corresponding to the data used in the arithmetic operation unit 113 from the valid video data decrypted by a decryptor 141 and extracted by an extractor 144. A comparator 145 compares an output of the arithmetic operation unit 143 with an arithmetic operation result extracted from data 140.

Abstract: Video data exploitation by alteration of data is prevented. An extractor 111 extracts valid video data in data 110 and predetermined data in the data. An inserter 114 inserts an arithmetic operation result of the predetermined data by an arithmetic operation unit 113 into the valid video data encrypted by an encryptor 112. An output of the inserter 114 is supplied to an extractor 144 through a transmission path 120. The encrypted valid video data and arithmetic operation resultant data of the arithmetic operation unit 113 are extracted. An arithmetic operation unit 143 executes the same arithmetic operation as that of the arithmetic operation unit 113 to data corresponding to the data used in the arithmetic operation unit 113 from the valid video data decrypted by a decryptor 141 and extracted by an extractor 144. A comparator 145 compares an output of the arithmetic operation unit 143 with an arithmetic operation result extracted from data 140.

Abstract: Input picture data are encrypted with high secrecy and restoration against an error of encrypted data. An EXOR circuit 100 calculates input picture data and a pseudo random sequence and obtains encrypted data. The obtained encrypted data are held in an FF circuit 101. The FF circuit 101 is reset for each line. Counters 102 and 103 count for each line or each frame and are reset for each frame or at the beginning of a program. An encryption device 105 encrypts outputs of an FF circuit 104 that holds a fixed value, the counters 103 and 102, and the FF circuit 101 with a key (K) and generates a pseudo random sequence. A shift register 106 divides the bit sequence. The EXOR 100 calculates the output of the shift register 106 and the input picture data and obtains encrypted data. Since the encrypted output is fed back, data cannot be stolen using a successive input of the same data.

Abstract: Improved time base error correcting apparatus of the type wherein time base errors in a video signal, such as a video signal reproduced by a video signal playback device, are corrected. The apparatus includes a main memory into which picture elements contained in each line interval of the video signal are written at a write-in rate that is synchronized with the time base information contained in that video signal, and from which the picture elements are read out at a reference rate. A drop-out detector detects drop-out conditions which may occur in the video information and synchronizing information portions of the video signal. Drop-out indications are stored in a drop-out condition memory so as to represent the positions within a line interval that drop-out has occurred. These drop-out indications are written into and read out of the drop-out condition memory in synchronism with the writing in and reading out of picture elements from the main memory.