| Revision as of 15:23, 27 October 2003 editEd Poor (talk | contribs)Extended confirmed users, Pending changes reviewers59,210 edits copy-edits, 1st para← Previous edit | Revision as of 15:30, 27 October 2003 edit undoEd Poor (talk | contribs)Extended confirmed users, Pending changes reviewers59,210 edits my 2 centsNext edit → | ||
| Line 1: | Line 1: | ||
| A '''dongle''' is a small hardware device that connects to a computer and acts as an authentication key for a particular piece of software running on that machine. | A '''dongle''' is a small hardware device that connects to a computer and acts as an authentication key for a particular piece of software running on that machine. Its purpose is to thwart unauthorized copying of software. | ||
| When the dongle is present, the software will run properly. When it is not present, the software will detect the dongle's absence; it will then restrict the operation of the software or even stop the program from running altogther. | |||
| ⚫ | The dongle is a form of ] or ] |
||
| ⚫ | The dongle is a form of ] or ] which some software sellers prefer because it is much harder to copy the dongle than it is to copy the software it authenticates. | ||
| Dongle schemes became popular in the ], and continued into the ]. Originally taking the form of simple passive devices that connected a ] in a predetermined manner, they rapidly evolved into active devices that contained a serial transceiver (]), and even a ] to handle transactions with the host. Later versions adopted the ] interface in preference to the serial interface. Modern dongles include built-in strong ], and special fabrication techniques designed to thwart ]. Typical dongles also now contain a reasonable amount of non-volatile memory, so that key parts of the software may be actually stored on the dongle. | Dongle schemes became popular in the ], and continued into the ]. Originally taking the form of simple passive devices that connected a ] in a predetermined manner, they rapidly evolved into active devices that contained a serial transceiver (]), and even a ] to handle transactions with the host. Later versions adopted the ] interface in preference to the serial interface. Modern dongles include built-in strong ], and special fabrication techniques designed to thwart ]. Typical dongles also now contain a reasonable amount of non-volatile memory, so that key parts of the software may be actually stored on the dongle. | ||
Revision as of 15:30, 27 October 2003
A dongle is a small hardware device that connects to a computer and acts as an authentication key for a particular piece of software running on that machine. Its purpose is to thwart unauthorized copying of software.
When the dongle is present, the software will run properly. When it is not present, the software will detect the dongle's absence; it will then restrict the operation of the software or even stop the program from running altogther.
The dongle is a form of copy protection or digital rights management which some software sellers prefer because it is much harder to copy the dongle than it is to copy the software it authenticates.
Dongle schemes became popular in the 1980s, and continued into the 1990s. Originally taking the form of simple passive devices that connected a parallel port in a predetermined manner, they rapidly evolved into active devices that contained a serial transceiver (UART), and even a microprocessor to handle transactions with the host. Later versions adopted the USB interface in preference to the serial interface. Modern dongles include built-in strong encryption, and special fabrication techniques designed to thwart reverse engineering. Typical dongles also now contain a reasonable amount of non-volatile memory, so that key parts of the software may be actually stored on the dongle.
One major snag with dongles is that they tie up a port on the host machine. This has been ameliorated to some extent by the adoption of USB, but is still a major drawback. There is also the obvious problem of losing the dongle, rendering the protected software useless. Also, if there is more than one application protected in this manner, the number of dongles becomes physically problematic.
There is also a potential weakness in the implementation of the protocol between the dongle and the protected software - it requires considerable design cunning to implement this in a fashion that is not easy to crack. For example, a naive implementation might simply define a function that checks for the dongle, returning true or false accordingly. This reduces all of the protection, however sophisticated, to a single bit value at one point in the program, so cracking the protection requires only the identification and manipulation of that single bit.