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Cryptomeria Cipher
The Cryptomeria cipher, also called C2, is a proprietary block cipher defined and licensed by the 4C Entity. It is the successor to CSS algorithm (used for DVD-Video) and was designed for the CPRM/CPPM digital rights management scheme which are used by DRM-restricted Secure Digital cards and DVD-Audio discs. Cipher details The C2 symmetric key algorithm is a 10-round Feistel cipher. Like DES, it has a key size of 56 bits and a block size of 64 bits. The encryption and decryption algorithms are available for peer review, but implementations require the so-called "secret constant", the values of the substitution box (S-box), which are only available under a license from the 4C Entity. The 4C Entity licenses a different set of S-boxes for each application (such as DVD-Audio, DVD-Video and CPRM). (Abstract is in German, rest is in English) Cryptanalysis In 2008, an attack was published against a reduced 8-round version of Cryptomeria to discover the S-box in a chosen-key scena ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptomeria Feistel Function
''Cryptomeria'' (literally "hidden parts") is a Monotypic taxon, monotypic genus of Pinophyta, conifer in the cypress family (biology), family Cupressaceae, formerly belonging to the family Taxodiaceae. It includes only one species, ''Cryptomeria japonica'' (synonym (taxonomy), syn. ''Cupressus japonica'' Carl Linnaeus the Younger, L.f.). It used to be considered by some to be Endemism, endemic to Japan (see remark below under 'Endemism'), where it is known as . The tree is called Japanese Cedar (plant), cedar or Japanese redwood in English. It has been extensively introduced and cultivated for wood production on the Azores. Description ''Cryptomeria'' is a very large evergreen tree, reaching up to tall and trunk diameter, with red-brown bark which peels in vertical strips. The leaf, leaves are arranged spirally, needle-like, long; and the seed cones globular, diameter with about 20–40 scales. It is superficially similar to the related Sequoiadendron giganteum, giant s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peer Review
Peer review is the evaluation of work by one or more people with similar competencies as the producers of the work (peers). It functions as a form of self-regulation by qualified members of a profession within the relevant field. Peer review methods are used to maintain quality standards, improve performance, and provide credibility. In academia, scholarly peer review is often used to determine an academic paper's suitability for publication. Peer review can be categorized by the type of activity and by the field or profession in which the activity occurs, e.g., medical peer review. It can also be used as a teaching tool to help students improve writing assignments. Henry Oldenburg (1619–1677) was a German-born British philosopher who is seen as the 'father' of modern scientific peer review. Professional Professional peer review focuses on the performance of professionals, with a view to improving quality, upholding standards, or providing certification. In academia, peer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DVD-RAM
DVD-RAM (DVD Random Access Memory) is a DVD-based disc specification presented in 1996 by the DVD Forum, which specifies rewritable DVD-RAM media and the appropriate DVD writers. DVD-RAM media have been used in computers as well as camcorders and personal video recorders since 1998. In May 2019, Panasonic, the only remaining manufacturer of DVD-RAM discs, announced that it would end production of DVD-RAM media by the end of that month, citing shrinking demand as the primary motivation. Panasonic made its discs under its own brand name and also under the Verbatim brand. Cartridge types Format DVD-RAM works by means of phase change technology which was chosen instead of magneto-optical technology (an already existing rewritable solution at the time) because it doesn't require a magnetic head and therefore it represented reduced complexity and costs. Phase change technology uses laser light to heat the surface of a phase changing alloy and allows it to go from a crystalline to a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CPRM
Content Protection for Recordable Media and Pre-Recorded Media (CPRM / CPPM) is a mechanism for controlling the copying, moving, and deletion of digital media on a host device, such as a personal computer, or other player. It is a form of digital rights management (DRM) developed by The 4C Entity, LLC (consisting of IBM, Intel, Matsushita and Toshiba). The CPRM / CPPM specification defines a renewable cryptographic method for restricting content when recorded on physical media. The currently implemented method utilizes the Cryptomeria cipher (C2) algorithm for symmetric encryption. The types of physical media supported include, but are not limited to, recordable DVD media and flash memory. The most widespread use of CPRM is arguably in Secure Digital cards such as the SD-Audio standard. Note that the available 0.9 revision includes only the portions of the specification covering DVD media. The CPRM / CPPM specification was designed to meet the requirements of intellectual pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DVD-VR
The DVD-VR standard defines a logical format for video recording on DVD-R, DVD-RW, and DVD-RAM style media, including the dual layer versions of these media. As opposed to media recorded with the DVD+VR recording standard, the resulting media are not DVD-Video compliant, and do not play back in some DVD-Video players. Most DVD video recorders in the market that support DVD-R, DVD-RW, or DVD-RAM media record to these media in DVD-VR mode, as well as in a DVD-Video compliant mode. It is possible to use the DVD-VR format with DVD+R and DVD+RW media, but no examples are known other than some PC based recording utilities. The standard was introduced in 1999 by the DVD Forum, and licensing is managed by the DVD Format/Logo Licensing Corporation. For each of the supported media, the full recording standard consists of three parts being: Physical Specifications (Part 1), File System Specifications (Part 2), and the Video Recording Specifications (Part 3). Feature overview The DVD-VR s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Media Key Block
The Media Key Block (MKB) is one of the keys included inside the copying protection system (DRM) AACS. This system is used to prevent Blu-ray and HD DVD formats from being copied. The system was developed by companies from the film industry and the electronics industry including IBM, Intel, Microsoft, Matsushita (Panasonic), Sony, Toshiba, The Walt Disney Company and Warner Bros. The MKB key is found in the physical support (the disc) together with the content of the disc encrypted. The ''MKB'' has the function of validating the reproduction devices on which the disc is being played and obtaining, from the devices codes, the key that will allow the decryption of the disc content. That is the Media Key (K_m). , version 78 has been the most recent MKB version. How it works ''Blu-Ray'' or ''HD-DVD'' have as content the encrypted data (usually video), the Volume ID (VID), the Encrypted Title Key(s) and the ''MKB''. The ''MKB'' is also found encrypted in the disc to prevent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Video Recorder
A digital video recorder (DVR) is an electronic device that records video in a digital format to a disk drive, USB flash drive, SD memory card, SSD or other local or networked mass storage device. The term includes set-top boxes with direct to disk recording, portable media players and TV gateways with recording capability, and digital camcorders. Personal computers are often connected to video capture devices and used as DVRs; in such cases the application software used to record video is an integral part of the DVR. Many DVRs are classified as consumer electronic devices; such devices may alternatively be referred to as personal video recorders (PVRs), particularly in Canada. Similar small devices with built-in (~5 inch diagonal) displays and SSD support may be used for professional film or video production, as these recorders often do not have the limitations that built-in recorders in cameras have, offering wider codec support, the removal of recording time limitations and hig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Broadcast Flag
A broadcast flag is a bit field sent in the data stream of a digital television program that indicates whether or not the data stream can be recorded, or if there are any restrictions on recorded content. Possible restrictions include the inability to save an unencrypted digital program to a hard disk or other non-volatile storage, inability to make secondary copies of recorded content (in order to share or archive), forceful reduction of quality when recording (such as reducing high-definition video to the resolution of standard TVs), and inability to skip over commercials. In the United States, new television receivers using the ATSC standard were supposed to incorporate this functionality by July 1, 2005. The requirement was successfully contested in 2005 and rescinded in 2011. FCC ruling Officially called "Digital Broadcast Television Redistribution Control," the FCC's rule is in 47 CFR 73.9002(b) and the following sections, stating in part: "No party shall sell or distr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-definition Television
High-definition television (HD or HDTV) describes a television system which provides a substantially higher image resolution than the previous generation of technologies. The term has been used since 1936; in more recent times, it refers to the generation following standard-definition television (SDTV), often abbreviated to HDTV or HD-TV. It is the current de facto standard video format used in most broadcasts: terrestrial broadcast television, cable television, satellite television and Blu-ray Discs. Formats HDTV may be transmitted in various formats: * 720p (1280 horizontal pixels × 720 lines): 921,600 pixels * 1080i (1920×1080) interlaced scan: 1,036,800 pixels (~1.04 MP). * 1080p (1920×1080) progressive scan: 2,073,600 pixels (~2.07 MP). ** Some countries also use a non-standard CEA resolution, such as 1440×1080i: 777,600 pixels (~0.78 MP) per field or 1,555,200 pixels (~1.56 MP) per frame When transmitted at two megapixels per frame, HDTV provides about five times ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lars Knudsen
Lars Ramkilde Knudsen (born 21 February 1962) is a Danish researcher in cryptography, particularly interested in the design and analysis of block ciphers, hash functions and message authentication codes (MACs). Academic After some early work in banking, Knudsen enrolled at Aarhus University in 1984 studying mathematics and computer science, gaining an MSc in 1992 and a PhD in 1994. From 1997-2001, he worked at the University of Bergen, Norway. Currently, Knudsen is a professor in the Department of Mathematics at the Technical University of Denmark. Ivan Damgård was Lars' mentor during his studies at Aarhus University. His Ph.D. was refereed by Bart Preneel. Publications Knudsen has published a couple of papers on cryptanalysis of cryptographic primitives, including the R-MAC scheme, the SHA-1 and MD2 hash functions, and a couple of block ciphers: DES, DFC, IDEA, ICE, LOKI, MISTY, RC2, RC5, RC6, SC2000, Skipjack, Square and SAFER. Knudsen was involved in designing some ciph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S-box
In cryptography, an S-box (substitution-box) is a basic component of symmetric key algorithms which performs substitution. In block ciphers, they are typically used to obscure the relationship between the key and the ciphertext, thus ensuring Shannon's property of confusion. Mathematically, an S-box is a vectorial Boolean function. In general, an S-box takes some number of input bits, ''m'', and transforms them into some number of output bits, ''n'', where ''n'' is not necessarily equal to ''m''. An ''m''×''n'' S-box can be implemented as a lookup table with 2''m'' words of ''n'' bits each. Fixed tables are normally used, as in the Data Encryption Standard (DES), but in some ciphers the tables are generated dynamically from the key (e.g. the Blowfish and the Twofish encryption algorithms). Example One good example of a fixed table is the S-box from DES (S5), mapping 6-bit input into a 4-bit output: Given a 6-bit input, the 4-bit output is found by selecting the row using t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Darmstadt University Of Technology
Darmstadt () is a city in the state of Hesse in Germany, located in the southern part of the Rhine-Main-Area (Frankfurt Metropolitan Region). Darmstadt has around 160,000 inhabitants, making it the fourth largest city in the state of Hesse after Frankfurt am Main, Wiesbaden, and Kassel. Darmstadt holds the official title "City of Science" (german: link=no, Wissenschaftsstadt) as it is a major centre of scientific institutions, universities, and high-technology companies. The European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) and the European Space Operations Centre (ESOC) are located in Darmstadt, as well as GSI Centre for Heavy Ion Research, where several chemical elements such as bohrium (1981), meitnerium (1982), hassium (1984), darmstadtium (1994), roentgenium (1994), and copernicium (1996) were discovered. The existence of the following elements were also confirmed at GSI Centre for Heavy Ion Research: nihonium (2012), flerovium (2009), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
