Using microelectromechanical system (MEMS) design, the Recodable Locking Device has six notched gear wheels each the size of a full stop to replicate a traditional locking mechanism on a silicon chip.
The resultant device gives a user just one chance to select the correct preset code from a million possible combinations - if the code is incorrect, the device mechanically locks shut until reset by the owner. Because of the simplicity of the device, the labs say, it is extremely easy to analyse for vulnerabilities.
The device is controlled by electrical signals, making it easy to integrate into existing computer security systems, and the owner can easily change the code at will. "The Recodable Locking Device should be of great interest to businesses and individuals who have computer networks, have sites on the Web, or require secure computers," said Frank Peter, the engineer who designed the device. "It would make it virtually impossible to break in to Web sites." As with all security devices, though, it would need to be part of a whole system and appropriately applied to be useful.
Some of the ideas on the chip are derived from Sandia's work with mechanical locking devices in weaponry control, others from the lab's history of MEMS research, and as it can be produced by the hundreds on a silicon wafer the same economies of scale apply to it as to any chip -- it is potentially very cheap to make.
"This device has a powerful potential -- one that is readily understood by almost everyone," said Larry Dalton, manager of Sandia's High Integrity Software Systems Engineering Department. "I've been told by Department of Defense people that this is the first real technical advancement in information security that they've seen in a long time."
The combination lock was invented in 1862, but this is the first time the concept has been integrated with modern digital production techniques.
Other applications that the design team envisage is in safety monitoring of dangerous systems: the same mechanism can be used to turn off a radiation therapy machine if too much radiation has been delivered.
This article seems to be about 4.5 years out of date, see the press release from Sandia dated 12 October 1998 at http://www.sandia.gov/media/hacker.htm, and the Communications of the ACM, Volume 42, Issue 7, July 1999, pp. 83-87, "The recodable locking device" by Plummer et al of Sandia.