Bus encryption is the use of
encrypted
In cryptography, encryption (more specifically, encoding) 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 plain ...
program instructions on a data
bus
A bus (contracted from omnibus, with variants multibus, motorbus, autobus, etc.) is a motor vehicle that carries significantly more passengers than an average car or van, but fewer than the average rail transport. It is most commonly used ...
in a computer that includes a
secure cryptoprocessor
A secure cryptoprocessor is a dedicated computer-on-a-chip or microprocessor for carrying out cryptographic operations, embedded in a packaging with multiple physical security measures, which give it a degree of tamper resistance. Unlike cryp ...
for executing the encrypted instructions. Bus encryption is used primarily in electronic systems that require high security, such as
automated teller machine
An automated teller machine (ATM) is an electronic telecommunications device that enables customers of financial institutions to perform financial transactions, such as cash withdrawals, deposits, funds transfers, balance inquiries or account ...
s, TV
set-top box
A set-top box (STB), also known as a cable converter box, cable box, receiver, or simply box, and historically television decoder or a converter, is an information appliance device that generally contains a Tuner (radio)#Television, TV tuner inpu ...
es, and secure data communication devices such as
two-way
Two-way or Two Way may refer to:
Music
* " 2-Way", a 2002 song by Lil' Romeo
* "Two Way" (song), by KT Tunstall and James Bay, 2016
Other uses
* Two-way, Cincinnati chili
Cincinnati chili (or Cincinnati-style chili) is a Mediterranean-spic ...
digital radios
Digital radio is the use of digital technology to transmit or receive across the radio spectrum. Digital transmission by radio waves includes digital broadcasting, and especially digital audio radio services. This should not be confused with Inter ...
.
Bus encryption can also mean encrypted data transmission on a data bus from one processor to another processor. For example, from the
CPU
A central processing unit (CPU), also called a central processor, main processor, or just processor, is the primary processor in a given computer. Its electronic circuitry executes instructions of a computer program, such as arithmetic, log ...
to a
GPU
A graphics processing unit (GPU) is a specialized electronic circuit designed for digital image processing and to accelerate computer graphics, being present either as a discrete video card or embedded on motherboards, mobile phones, personal ...
which does not require input of encrypted instructions. Such bus encryption is used by
Windows Vista
Windows Vista is a major release of the Windows NT operating system developed by Microsoft. It was the direct successor to Windows XP, released five years earlier, which was then the longest time span between successive releases of Microsoft W ...
and newer Microsoft operating systems to protect certificates,
BIOS
In computing, BIOS (, ; Basic Input/Output System, also known as the System BIOS, ROM BIOS, BIOS ROM or PC BIOS) is a type of firmware used to provide runtime services for operating systems and programs and to perform hardware initialization d ...
, passwords, and program authenticity. PVP-UAB (
Protected Video Path) provides bus encryption of premium video content in PCs as it passes over the
PCIe
PCI Express (Peripheral Component Interconnect Express), officially abbreviated as PCIe, is a high-speed standard used to connect hardware components inside computers. It is designed to replace older expansion bus standards such as Peripher ...
bus to graphics cards
Encryption in Microsoft Windows Vista
to enforce digital rights management
Digital rights management (DRM) is the management of legal access to digital content. Various tools or technological protection measures, such as access control technologies, can restrict the use of proprietary hardware and copyrighted works. DRM ...
.
The need for bus encryption arises when multiple people have access to the internal circuitry of an electronic system, either because they service and repair such systems, stock spare components for the systems, own the system, steal the system, or find a lost or abandoned system. Bus encryption is necessary not only to prevent tampering of encrypted instructions that may be easily discovered on a data bus or during data transmission, but also to prevent discovery of decrypted instructions that may reveal security weaknesses that an intruder can exploit.
In TV set-top boxes
A set-top box (STB), also known as a cable box, receiver, or simply box, and historically television decoder or a converter, is an information appliance device that generally contains a TV tuner input and displays output to a television set, t ...
, it is necessary to download program instructions periodically to customer's units to provide new features and to fix bugs. These new instructions are encrypted before transmission, but must also remain secure on data buses and during execution to prevent the manufacture of unauthorized
Authorization or authorisation (see spelling differences), in information security, computer security and IAM (Identity and Access Management), is the function of specifying rights/privileges for accessing resources, in most cases through an a ...
cable TV boxes. This can be accomplished by secure crypto-processors that read encrypted instructions on the data bus from external data memory, decrypt the instructions in the cryptoprocessor, and execute the instructions in the same cryptoprocessor.
See also
*Copy protection
Copy protection, also known as content protection, copy prevention and copy restriction, is any measure to enforce copyright by preventing the reproduction of software, films, music, and other media.
Copy protection is most commonly found on vid ...
Notes
References
* R. Elbaz, et al., Hardware Engines for Bus Encryption -- A Survey, 200
PDF
* Robert M. Best, US Paten
4,278,837
July 14, 1981
{{DEFAULTSORT:Bus Encryption
Cryptography