摘要:
In the present invention, apparatuses are classified into a plurality of categories, and based on a media key and device key data held by apparatuses belonging to the respective categories, revocation data intended for revoking the device key held by a specific apparatus of the respective categories is generated for the respective categories, and recorded on a recording medium.
摘要:
The invention provides a recording apparatus and a reproduction apparatus that are able to prevent illegitimate use of contents. A recording medium stores therein a medium inherent number in the unrewritable area. The recording apparatus writes media key data and an encrypted content onto the recording medium. The media key data includes encrypted media keys generated by (i) for each of unrevoked reproduction apparatuses, encrypting a media key using a device key of the unrevoked reproduction apparatus respectively, and (ii) for each of revoked reproduction apparatuses, encrypting detection information using a device key of the revoked reproduction apparatus respectively. The reproduction apparatus decrypts the encrypted media key using a device key to generate a decryption media key, judges whether the decryption media key is the detection information or not, and prohibits the encrypted content recorded on the recording medium from being decrypted when having judged in the affirmative.
摘要:
A parameter generation apparatus for generating parameters causing no decryption error for an NTRU cryptosystem so that an encrypted communication can be carried out between an encryption apparatus and a decryption apparatus in a secure and reliable manner, is comprised of: a provisional parameter generation unit operable to generate a set of provisional parameters that do not cause any decryption errors, based on error condition information that is provided in advance, said error condition information indicating a condition for causing no decryption error; and an output parameter generation unit operable to generate an output parameter that does not cause any decryption errors, using said set of provisional parameters, based on a lattice constant that is calculated from said set of provisional parameters.
摘要:
Provided is a content distribution system that prevents different keys to be derived between an encryption apparatus and a decryption apparatus. A random-number generating unit 112d, in an encryption apparatus 110d, generates a random number s, and a first function unit 113d generates a functional value G (s) of the random number s, and generates a verification value a and a shared key K from the functional value G(s). An encryption unit 114d generates a first cipher text c1 of the verification value a using a public-key polynomial h, and a second function unit 115d generates a functional value H(a,c1) of the verification value a and the first cipher text c1, and a random-number mask unit 116d generates a second cipher text c2=s xor H(a,c1). A decryption unit 123d, in a decryption apparatus 120d, decrypts the first cipher text c1 using a secret-key polynomial f, to generate a decryption verification value a'. A third function unit 124d generates a functional value H(a',c1) of the decryption verification value a' and the first cipher text c1, and a random-number mask removal unit 125d generates a decryption random number s'=c2 xor H(a',c1). A fourth function unit 126d generates a hash functional value G (s') of the decryption random number s', and generates a verification value a'' and a shared key K' from the functional value G(s'). A comparison unit 127d outputs the shared key K' if the decryption verification value a' is equal to the verification value a''.
摘要:
The present invention pertains to a transmission apparatus (110) for generating an encrypted text by encrypting a plaintext, which includes a parameter storage unit (112) for storing a random parameter (the number of terms whose coefficients indicate 1) adapted to an encryption key and an encryption apparatus and a decryption apparatus; encryption unit (116) for generating, from the plaintext, the encrypted text using the encryption key and the random parameter stored in the parameter storage unit (112), complying with an encryption algorithm based on the NTRU method; and a key updating unit (118) for updating the random parameter stored in the parameter storage unit (112) and the encryption key, as time passes.
摘要:
An information recording medium including a lead-in region and a data recording region, wherein key information is recorded in the lead-in region and scrambled data are recorded in the data recording region. The scrambled data are descrambled on the basis of the key information.
摘要:
A secure device that can store programs therein for performing the programs, including:a low-protection level storage unit;a high-protection level storage unit;a program acquiring unit that acquires a program and corresponding additional information, the additional information used for determining a storage destination of the acquired program;an additional information analyzing unit that stores the acquired program in one of the low-protection level storage unit and the high-protection level storage unit, according to additional information;an area searching unit;a protection level judging unit; anda program storing unit.
摘要:
A video signal and an audio signal are time division multiplexed, encrypted, and transmitted. A transmission side time-compresses the audio signal, multiplexes, encrypts, and transmits the time-compressed audio signal in a blanking period of the video signal. Control is performed using an audio signal data enable signal ADE, and a audio signal/video signal switch signal.
摘要:
A copyright protection system (100) includes a recording device (10) and a reproduction device (30). The recording device (10) writes encrypted content (15), an encrypted content key (12,13) for decrypting the encrypted content (15), and license information (16) on a recording medium (20) on which a unique media number (21) has been recorded in an unrewritable state. The license information (16) is generated using both the media number (21) and the encrypted content key (13), and therefore reflects both values. The reproduction device (30) reads the media number (21), the encrypted content key (13,23), and the license information (16,22) from the recording medium (20), and judges (36) whether the license information (16,22) reflects both the media number (21) and the encrypted content key (13,23). Only if the license information (16,22) reflects both values, the reproduction device (30) decrypts the encrypted content key (32,33), and decrypts the encrypted content using the content key (12,13). In this way, the copyright protection system (100) allows only original recording media (20) to be reproduced, and prohibits reproduction of copy recording media.