Abstract:
The digital signal recording/reproducing apparatus inputs a digital signal having a control flag as to a temporary copy permission, and records the digital signal temporarily into a recording medium in accordance with conditions in the control flag, then reproducing the digital signal temporarily from the recording medium in accordance with the conditions in the control flag. The recording/reproducing of the temporary copy is permitted, depending on the following conditions: The recording medium's type, the reproducing point-in-time, the reproducing time-period, and the reproducing frequency. With this method employed, even in a program permitting no recording, the temporary recording/reproducing is permitted under a condition of being limited to the time-shift recording on the receiving side.
Abstract:
A system effecting a data reproducing method for a plurality of devices, for sending and receiving data by authenticating the plurality of devices with each other, said data reproducing method including: selecting, from a plurality of descrambling methods, a descrambling method corresponding to a type of said data, executing authentication by an authenticating method corresponding to the selected descrambling method, where the authenticating method is selected from a plurality of authenticating methods, and reproducing said data.
Abstract:
A time stamp generating system has a time distribution server for generating time data depending on time and a user PC for holding time certification objective digital data. The time distribution server generates time data corresponding to a time point and distributes the time data. The user PC calculates time stamp generating data by using the time certification objective data as an input, acquires the time data generated by the time distribution server, and processes the time data on the basis of the time stamp generating data to obtain a time stamp.
Abstract:
To enable the control of rendering contents in part by using digital watermark technique:a contents serving center for embedding watermark in contents 4 embeds control information as digital watermarks within at least one of a plurality of blocks constituting electronic data by which contents are represented, thereby specifying the application of filtering to a part of the contents corresponding to the block; a contents distribution center 1 distributes the watermark-including contents to a receiving terminal 2 where checks the blocks of the received data to detect whether the control information as digital watermarks is embedded therein and applies the filtering to the block for which the embedded control information embedded has been detected in advance of reproducing the contents.
Abstract:
A method of embedding information into contents includes a changeable range calculating step of obtaining a range where value change of the contents is imperceptible to the human being and a step of embedding information by changing the values of the contents within the changeable range.
Abstract:
A digital watermark information judging method is provided for detecting digital watermark information which is embedded in at least one element of digital data by altering at least one data value of the element. The method first estimates the data value of the element by using data values of at least two neighboring elements of data located near the element, then compares the estimated data value with an actual data value of the element to detect the amount of the alteration, and judges the presence and value of the digital watermark information based on the amount of the alteration.
Abstract:
An extraction process includes the steps of carrying out a geometric transformation on a picture being inspected to transform the size of the picture being inspected into a reduced scale of an original picture; creating a plurality of degraded original pictures with different types each obtained as a result of degradation of the original picture; creating a plurality of differential pictures by subtraction of the degraded original pictures with different types from the picture being inspected with a transformed size to cancel degradation components in the picture being inspected with a transformed size; and extracting the information corresponding to the authentication information.
Abstract:
A method and a device for managing a computer network, especially a technique for ensuring the security of a network. A computer network system in which computers are connected to each other through transmission lines, each computer stores the data which constitutes a moving type software exclusively used for security and transmitted together with a message when the computer transmits the message to another computer of the system, and executes the moving type software by using the stored data upon receiving a message from another computer.
Abstract:
A system effecting a data reproducing method for a plurality of devices, for sending and receiving data by authenticating the plurality of devices with each other, said data reproducing method including: selecting, from a plurality of descrambling methods, a descrambling method corresponding to a type of said data, executing authentication by an authenticating method corresponding to the selected descrambling method, where the authenticating method is selected from a plurality of authenticating methods, and reproducing said data.
Abstract:
A technology of digital watermarking for binary images (including documents) is provided, which is capable of adjusting the amount of information to be embedded while avoiding the deterioration of image quality as far as possible. The watermark information is inserted by giving the standard for judgment of modification and the order of preference for modification according to the characteristic properties of the human visual sense for binary images and performing modification on pixels sequentially in the descending order of preference.