摘要:
A content protection system prevents illegal key acquisition, without checking uniqueness of device keys. The content protection system includes a key data generation apparatus and a user terminal. The key data generation apparatus converts first key data, which is for using content, based on a predetermined conversion rule, thereby generating second key data, encrypts the second key data using a device key held by valid terminals, and outputs the encrypted key data. The user terminal obtains the encrypted key data, decrypts the encrypted key data using a device key held by the user terminal, thereby generating second key data, converts the second key data based on a re-conversion rule corresponding to the conversion rule, thereby generating the first key data, and uses the content with use of the generated first key data.
摘要:
An encryption scheme management method according to the present invention is an encryption scheme management method which manages encryption schemes utilized for distributing encrypted data, and includes request receiving which receives encryption scheme switching request from a client device, selecting an encryption scheme from the encryption schemes, generating circuit forming information for forming a decrypting circuit which decrypts the data encrypted by the selected encryption scheme, and sending the circuit forming information to the client device.
摘要:
The present invention provides an apparatus for securely acquire a circuit configuration information set corresponding to a new cryptosystem without increasing the number of reconfigurable circuits. A content playback apparatus 100 includes an FPGA 122 that is reconfigurable. The content playback apparatus 100 stores a decryption circuit program that shows the structure of a decryption circuit that executes decryption in accordance with a prescribed cryptosystem. The FPGA is reconfigured in accordance with the program to configure the decryption circuit. The playback apparatus 100 acquires, from outside, an encrypted file that has been generated by encrypting a file including a decryption circuit program corresponding to the new cryptosystem in accordance with the prescribed cryptosystem, and decrypts the encrypted file by the decryption circuit.
摘要:
The present invention aims to provide an information security apparatus that counters a simple power analysis attack (SPA) on an information security apparatus such as an RSA cryptosystem. The information security apparatus uses a multiplication with 1 in a Montgomery domain. 1 in the Montgomery domain is determined depending on a modulus and an integer k, which is greater than a number of bits of a modulus p. Therefore, it is hard for attackers who do not know p or k to analyze. Also, even if an analyzer can predict the Hamming weight, it is possible to further improve the safety against the SPA by modifying k or the modulus at random.