A software protection dongle (commonly known as a dongle or key) 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.
In software protection, dongles are two-interface security tokens with transient data flow with a pull communication that reads security data from the dongle. In the absence of these dongles, certain software may run only in a restricted mode, or not at all. In addition to software protection, dongles can enable functions in electronic devices, such as receiving and processing encoded video streams on television sets.
Etymology
The Merriam-Webster dictionary states that the "First known use of
dongle" was in 1981 and that the etymology was "perhaps alteration of dangle."

Dongles rapidly evolved into active devices that contained a serial transceiver (
UART) and even a
microprocessor
A microprocessor is a computer processor where the data processing logic and control is included on a single integrated circuit, or a small number of integrated circuits. The microprocessor contains the arithmetic, logic, and control circu ...
to handle transactions with the host. Later versions adopted the
USB interface, which became the preferred choice over the
serial or parallel interface.
A 1992 advertisement for
Rainbow Technologies
SafeNet, Inc. was an information security company based in Belcamp, Maryland, United States, which was acquired in August 2014 by the French security company Gemalto. Gemalto was, in turn, acquired by Thales Group in 2019. The former SafeNet's ...
claimed the word dongle was derived from the name "Don Gall". Though untrue, this has given rise to an
urban myth.
Usage
Efforts to introduce dongle copy-protection in the mainstream software market have met stiff resistance from users. Such copy-protection is more typically used with very expensive packages and
vertical market software such as
CAD/
CAM software,
cellphone flasher/JTAG debugger software,
MICROS Systems hospitality and special retail software,
digital audio workstation
A digital audio workstation (DAW) is an electronic device or application software used for recording, editing and producing audio files. DAWs come in a wide variety of configurations from a single software program on a laptop, to an integra ...
applications, and some
translation memory packages.
In cases such as prepress and printing software, the dongle is encoded with a specific, per-user license key, which enables particular features in the target application. This is a form of tightly controlled licensing, which allows the vendor to engage in vendor lock-in and charge more than it would otherwise for the product. An example is the way
Kodak licenses
Prinergy to customers: When a
computer-to-plate output device is sold to a customer, Prinergy's own license cost is provided separately to the customer, and the base price contains little more than the required licenses to output work to the device.
USB dongles are also a big part of
Steinberg's audio production and editing systems, such as
Cubase, WaveLab,
Hypersonic,
HALion, and others. The dongle used by Steinberg's products is also known as a Steinberg Key. The Steinberg Key can be purchased separately from its counterpart applications and generally comes bundled with the "Syncrosoft License Control Center" application, which is cross-platform compatible with both Mac OS X and Windows.
Some software developers use traditional USB flash drives as software license dongles that contain hardware serial numbers in conjunction with the stored device ID strings, which are generally not easily changed by an end-user. A developer can also use the dongle to store user settings or even a complete "portable" version of the application. Not all flash drives are suitable for this use, as not all manufacturers install unique serial numbers into their devices.
Although such medium security may deter a casual hacker, the lack of a processor core in the dongle to authenticate data, perform encryption/decryption, and execute inaccessible binary code makes such a passive dongle inappropriate for all but the lowest-priced software. A simpler and even less secure option is to use unpartitioned or unallocated storage in the dongle to store license data. Common USB flash drives are relatively inexpensive compared to dedicated security dongle devices, but reading and storing data in a flash drive are easy to intercept, alter, and bypass.
Issues
There are potential weaknesses in the implementation of the protocol between the dongle and the copy-controlled software. For example, a simple implementation might define a
function to check for the dongle's presence, returning "true" or "false" accordingly, but the dongle requirement can be easily circumvented by modifying the software to always answer "true".
Modern dongles include built-in strong encryption and use fabrication techniques designed to thwart
reverse engineering
Reverse engineering (also known as backwards engineering or back engineering) is a process or method through which one attempts to understand through deductive reasoning how a previously made device, process, system, or piece of software accompli ...
. Typical dongles also now contain
non-volatile memory
Non-volatile memory (NVM) or non-volatile storage is a type of computer memory that can retain stored information even after power is removed. In contrast, volatile memory needs constant power in order to retain data.
Non-volatile memory typ ...
— essential parts of the software may actually be stored and executed on the dongle. Thus dongles have become
secure cryptoprocessors that execute program instructions that may be input to the cryptoprocessor only in encrypted form. The original secure cryptoprocessor was designed for copy protection of personal computer software (see US Patent 4,168,396, Sept 18, 1979)
US Patent 4,168,396
/ref> to provide more security than dongles could then provide. See also bus encryption.
Hardware cloning, where the dongle is emulated by a device driver, is also a threat to traditional dongles. To thwart this, some dongle vendors adopted smart card product, which is widely used in extremely rigid security requirement environments such as military and banking, in their dongle products.
A more innovative modern dongle is designed with a code porting process which transfers encrypted parts of the software vendor's program code or license enforcement into a secure hardware environment (such as in a smart card OS, mentioned above). An ISV can port thousands of lines of important computer program
A computer program is a sequence or set of instructions in a programming language for a computer to execute. Computer programs are one component of software, which also includes documentation and other intangible components.
A computer progra ...
code into the dongle.
In addition, dongles have been criticized because as they are hardware, they are easily lost and prone to damage, potentially increasing operational costs such as device cost and delivery cost.
Game consoles
Some unlicensed titles for game consoles (such as '' Super 3D Noah's Ark'' or '' Little Red Hood'') used dongles to connect to officially licensed ROM cartridges, in order to circumvent the authentication chip embedded in the console.
Some cheat code devices, such as the GameShark and Action Replay use a dongle. Typically it attaches to the memory card slot of the system, with the disc based software refusing to work if the dongle is not detected. The dongle is also used for holding settings and storage of new codes, added either by the user or through official updates, because the disc, being read only, cannot store them. Some dongles will also double as normal memory cards.
See also
* Digital rights management
* Hardware restrictions
A hardware restriction (sometimes called hardware DRM) is low-level protection enforced by electronic components. The hardware restriction scheme may protect against physical or malware attacks or complement a digital rights management system imp ...
* License manager
* Lock-out chip
In a general sense, a lockout chip is a chip within an electronic device to prevent other manufacturers from using a company's device to perform certain functions.
A notable example is the lockout chip found in Nintendo's Nintendo Entertainment Sy ...
* Product activation
* Security token
* Trusted client
* Software monetization
References
External links
Jargon File: dongle
{{DEFAULTSORT:Dongle, software protection
Copyright infringement of software
Copy protection
Digital rights management
Proprietary hardware
Software licenses
Warez