Content Protection for Recordable Media and Pre-Recorded Media (CPRM / CPPM) is a mechanism for restricting 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.[1] 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 property owners while balancing the implementation requirements of manufacturers. To accomplish these requirements, the system defined by the specification relies on public-key cryptography's key management for interchangeable media, content encryption, and "media-based renewability."
The use of the CPRM specification and access to the cryptographic materials required to implement it requires a license from 4C Entity, LLC. The license includes a facsimile key for the product which uses CPRM / CPPM technology.
A controversial proposal to add generic key exchange commands (that could be utilized by CPRM and other content restriction technologies) to ATA specifications for removable hard drives was abandoned after outcry in 2001.[2] CPRM is widely deployed in the popular Secure Digital card consumer-electronics flash memory format.[citation needed]
In cryptography, encryption is the process of transforming information in a way that, ideally, only authorized parties can decode. This process converts the original representation of the information, known as plaintext, into an alternative form known as ciphertext. Despite its goal, encryption does not itself prevent interference but denies the intelligible content to a would-be interceptor.
Pretty Good Privacy (PGP) is an encryption program that provides cryptographic privacy and authentication for data communication. PGP is used for signing, encrypting, and decrypting texts, e-mails, files, directories, and whole disk partitions and to increase the security of e-mail communications. Phil Zimmermann developed PGP in 1991.
DVD-Audio is a digital format for delivering high-fidelity audio content on a DVD. DVD-Audio uses most of the storage on the disc for high-quality audio and is not intended to be a video delivery format.
CompactFlash (CF) is a flash memory mass storage device used mainly in portable electronic devices. The format was specified and the devices were first manufactured by SanDisk in 1994.
A software protection dongle is an electronic copy protection and content protection device. When connected to a computer or other electronics, they unlock software functionality or decode content. The hardware key is programmed with a product key or other cryptographic protection mechanism and functions via an electrical connector to an external bus of the computer or appliance.
High-bandwidth Digital Content Protection (HDCP) is a form of digital copy protection developed by Intel Corporation to prevent copying of digital audio and video content as it travels across connections. Types of connections include DisplayPort (DP), Digital Visual Interface (DVI), and High-Definition Multimedia Interface (HDMI), as well as less popular or now deprecated protocols like Gigabit Video Interface (GVIF) and Unified Display Interface (UDI).
S/MIME is a standard for public-key encryption and signing of MIME data. S/MIME is on an IETF standards track and defined in a number of documents, most importantly RFC 8551. It was originally developed by RSA Data Security, and the original specification used the IETF MIME specification with the de facto industry standard PKCS #7 secure message format. Change control to S/MIME has since been vested in the IETF, and the specification is now layered on Cryptographic Message Syntax (CMS), an IETF specification that is identical in most respects with PKCS #7. S/MIME functionality is built into the majority of modern email software and interoperates between them. Since it is built on CMS, MIME can also hold an advanced digital signature.
There are a number of standards related to cryptography. Standard algorithms and protocols provide a focus for study; standards for popular applications attract a large amount of cryptanalysis.
Broadcast encryption is the cryptographic problem of delivering encrypted content over a broadcast channel in such a way that only qualified users can decrypt the content. The challenge arises from the requirement that the set of qualified users can change in each broadcast emission, and therefore revocation of individual users or user groups should be possible using broadcast transmissions, only, and without affecting any remaining users. As efficient revocation is the primary objective of broadcast encryption, solutions are also referred to as revocation schemes.
The 4C Entity is a digital rights management (DRM) consortium formed by IBM, Intel, Panasonic and Toshiba that has established and licensed interoperable cryptographic protection mechanisms for removable media technologies. 4C Entity was founded in 1999 when Warner Music approached the companies to develop stronger DRM technologies for the then-novel DVD-Audio format after Intel’s CSS DRM technology was hacked.
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 and was designed for the CPRM/CPPM digital rights management scheme which are used by DRM-restricted Secure Digital cards and DVD-Audio discs.
The High-Definition Audio-Video Network Alliance (HANA) was a cross-industry collaboration of members addressing the end-to-end needs of connected, HD, home entertainment products and services. Leading companies formed the organization from the four industries most affected by the HD revolution: content providers, consumer electronics, service providers, and information technology. HANA created design guidelines for secure high-definition audio-video networks that would speed the creation of new, high-quality, easy-to-use HD products. HANA membership was open to all companies involved in the digital entertainment industry. HANA was dissolved in September 2009, and the 1394 Trade Association assumed control of all HANA-generated intellectual property.
The Broadcast Protection Discussion Group (BPDG) is a working group of content providers, television broadcasters, consumer electronics manufacturers, information technology companies, interested individuals and consumer activists. The group was formed specifically for the purpose of evaluating the suitability of the broadcast flag for preventing unauthorized redistribution and to determine whether there was substantial support for the broadcast flag. The group completed its mission with the release of the BPDG Report.
The Advanced Access Content System (AACS) is a standard for content distribution and digital rights management, intended to restrict access to and copying of the post-DVD generation of optical discs. The specification was publicly released in April 2005. The standard has been adopted as the access restriction scheme for HD DVD and Blu-ray Disc (BD). It is developed by AACS Licensing Administrator, LLC, a consortium that includes Disney, Intel, Microsoft, Panasonic, Warner Bros., IBM, Toshiba and Sony. AACS has been operating under an "interim agreement" since the final specification has not yet been finalized.
Blu-ray is a digital optical disc data storage format designed to supersede the DVD format. It was invented and developed in 2005 and released worldwide on June 20, 2006, capable of storing several hours of high-definition video. The main application of Blu-ray is as a medium for video material such as feature films and for the physical distribution of video games for the PlayStation 3, PlayStation 4, PlayStation 5, Xbox One, and Xbox Series X. The name refers to the blue laser used to read the disc, which allows information to be stored at a greater density than is possible with the longer-wavelength red laser used for DVDs.
HD DVD is an obsolete high-density optical disc format for storing data and playback of high-definition video. Supported principally by Toshiba, HD DVD was envisioned to be the successor to the standard DVD format, but lost to Blu-ray, supported by Sony and others.
The Content Scramble System (CSS) is a digital rights management (DRM) and encryption system employed on many commercially produced DVD-Video discs. CSS utilizes a proprietary 40-bit stream cipher algorithm. The system was introduced around 1996 and was first compromised in 1999.
Protected Streaming is a DRM technology by Adobe. The aim of the technology is to protect digital content from unauthorized use.
A dongle is a small piece of computer hardware that connects to a port on another device to provide it with additional functionality, or enable a pass-through to such a device that adds functionality.
Widevine is a proprietary digital rights management (DRM) system developed by Google. It provides content protection for media. Widevine is divided into three security levels with differing levels of protection depending on the hardware present on the device. Widevine is included in most major web browsers and in Android and iOS.
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