摘要:
Subject matter includes exemplary systems and related methods for fully scalable encryption of scalable multimedia. A scalable bitstream encrypted using the subject matter maintains full functionality of scalable features in the encrypted form. The exemplary scalable encryption allows transcoding, rate shaping, and other operations directly on the ciphertext without degradation of scalable compression efficiency and error resiliency.
摘要:
An exemplary digital rights management engine and related methods divides multimedia content into service level layers, encrypts at least some of the layers, and offers access to the encrypted layers by permission. The multimedia content may be layered using multiple different layering approaches simultaneously, and access to the different types of layers may be offered simultaneously. One of the layers may be left unencrypted to allow free browsing of a low quality service level. An exemplary system of key management for digital rights management is also disclosed.
摘要:
Systems and methods configured for recoding an odd integer and elliptic curve point multiplication are disclosed, having general utility and also specific application to elliptic curve point multiplication and cryptosystems. In one implementation, the recoding is performed by converting an odd integer k into a binary representation. The binary representation could be, for example, coefficients for powers of two representing the odd integer. The binary representation is then configured as comb bit-columns, wherein every bit-column is a signed odd integer. Another implementation applies this recoding method and discloses a variation of comb methods that computes elliptic curve point multiplication more efficiently and with less saved points than known comb methods. The disclosed point multiplication methods are then modified to be Simple Power Analysis (SPA)-resistant.
摘要:
A fast and secure syntax compliant encryption schema, “locally iterative encryption,” can produce compliant ciphertext for a general syntax specification. In one implementation, an engine partitions a data stream into blocks, and encrypts each block iteratively until syntax compliance conditions are met. A system using the schema can utilize either stream ciphers or block ciphers in different modes. Locally iterative encryption methods are fast and remain at approximately the same speed even as the length of the data stream to be encrypted increases. Besides providing superior processing speed, the locally iterative encryption schema is also more robust to errors in the resulting ciphertext and in the resulting decrypted plaintext than conventional syntax compliant encryption techniques. Locally iterative encryption is secure as long as an underlying encryption cipher selected for use in the schema is secure.
摘要:
A fuel cell for production of electrical energy, such as a fuel cell, comprising a fuel chamber (1), an anode (2a), a cathode (2b), an electrolyte (3) disposed between said anode and said cathode, an oxidant chamber (4), wherein said chambers (1 and 4) enclose said anode, cathode and electrolyte, wherein a fuel flowing from the fuel chamber is oxidized at the anode, thereby producing electrical energy, wherein said electrolyte (3) is a ceramic composite electrolyte comprising at least one salt and at least one oxide in mixture.
摘要:
A flexible framework for generating “scalable layered access” codestreams allows a bitstream architect to select the number of access types and the number of access layers within each access type. At least some of the access layers are encrypted (or scrambled). Some of the access layers may be left unencrypted or unscrambled to allow free access to those layers. The framework facilitates simultaneous access of multimedia content by different users enjoying selective decryption of different access types and different access layers. An exemplary key schema for the framework sends only one or only a few keys to an end user for a given access layer, from which decryption keys for the content can be derived by hashing and then combining under a Group Diffie-Hellman key agreement. In one implementation, only one key is sent in a license to an end user and other partial key information for Group Diffie-Hellman combination with the licensed key is included in the publicly distributed codestream.
摘要:
3-Descladinosyl-6-O-carbamoyl and 6-O-carbonoyl macrolide antibacterial agents of the formula: wherein R1, W, R3, R4, R5, R6, X, X′, and Z are as described herein and in which the substituents have the meaning indicated in the description. These compounds are useful as antibacterial agents.
摘要:
Multimedia data embedding, such as video, image or audio data watermarking. In one embodiment, a computer-implemented method first receives a vector x of N data samples, where X=[x(0)x(1) . . . x(N−1)] and represents multimedia. Next, the method receives a vector p, where P=[p(0)p(1) . . . p(N−1)] and represents a pseudo-random sequence. Finally, the method generates a new vector x′ in which the vector p is embedded in the vector x, such that x′=[x′(0)x′(1) . . . x′(N−1)] and x′=x+aq, where a comprises a perception-based scaling factor and the vector q comprises a perceptually weighted pseudo-random sequence based on the vector p.
摘要:
A method and apparatus for digital watermarking to resolve multiple claims of ownership is disclosed. According to one embodiment of the invention, a first watermark requiring the host data for detection is embedded into the host data. A second watermark is also embedded into the host data. According to another embodiment of the invention, a pseudo-random sequence acting as a watermark is generated based on two random keys. One of the two random keys is related to the author of the host data into which the watermark is to be embedded, whereas the other of the two random keys is dependent on the host data itself.