National Semiconductor today announced the HiSeC(tm) Rolling Code Generator and Decoder, a solution that generates and decodes signals for remote keyless entry (RKE) applications. Unlike a majority of today's keyless entry products which send a fixed code signal, National's device generates what is known as a "non-reversible" rolling code signal. This means this remote keyless entry device generates a new random signal every time it is activated making it nearly impossible to break the code which dramatically improves overall security.
According to the Federal Bureau of Investigation, more than 1.5 million cars were stolen in the United States in 1993, the most recent period for which statistics are available. At an average replacement cost of $4,808, the value of all stolen vehicles was nearly $7.5 billion. This is part of the reason why, according to the National Institute of Justice, that consumers will spend more than $100 billion on private security by the year 2000.
"The consumer wants the convenience of remote security, but only if the degree of security meets or exceeds the equivalent mechanical device," said Anne Gregory, marketing manager for memory products with National.
For example, automobiles with keyless security systems are vulnerable to theft because the signal from a keyless security system can be intercepted. Therefore, when an owner leaves a car, the culprit can simply replay the recorded signal to gain access to the vehicle.
National's HiSeC Rolling Code Generator eliminates this inherent weakness in a fixed code signal. Again, using the automobile as an example, the HiSeC Rolling Code Generator generates a new code every time so an intercepted signal will not be recognized by the vehicle's receiver.
"We view the HiSeC Rolling Code solution as a genuine deterrent to car theft," said Gregory. The size of the HiSeC Rolling Code Generator provides another key benefit. Given the tiny dimensions of the device, manufacturers can incorporate non-reversible rolling code functionality in the same size of device used for today's fixed code products.
In addition to the automobile market, National has earmarked the HiSeC Rolling Code Solution for home security systems and other remote applications such as cellular phones.
National's Patented Coding Scheme - The challenge in developing the HiSeC Rolling Code Generator's patented coding was to create a scheme with near-infinite possibilities that required little memory. The success of this engineering effort can be seen in the device's ability to randomly generate a code from 248 (over 281.5 trillion) possibilities. If you could try 1,000 codes a minute, it would take over 500,000 years to search every possible code. At the same time, the coding scheme fits into only 13 bytes of memory, thereby saving cost.
To achieve its high-security level, the HiSeC Rolling Code Generator combines the contents of several dynamic data registers in a non-linear manner which produces an encoded output. Data in the registers is comprised of a mixture of user programmable data, factory programmable data and randomized data. This inherently random and separate data is encoded by clocking it through a non-linear logic block and feeding part of the output back to produce a final coded output. Such coded output has a high degree of linear complexity and correlation immunity.
The HiSeC Rolling Code Generator consists of a programmable logic device (available in SO8 and S14 package sizes) holding National's patented coding scheme.
Turnkey and Custom Solutions - National provides the HiSeC Rolling Code Generator today, and will provide the HiSeC Rolling Code Decoder in production units in Mid-April, as an off-the-shelf solution. As a result, the manufacturer will not need to invest any engineering efforts to understand the HiSeC non-reversible rolling code scheme.
For large volume manufacturers who want unique features in the decoder, National will provide the necessary software algorithm to decode the HiSeC Rolling Code Generator's signal. This software is available for COP8, National's family of 8 bit microcontrollers. For instance, a manufacturer can replace an existing microcontroller solution that lacks security with a member of the COP8 family which will integrate the original functionality, plus add the security of the HiSeC Rolling Code solution.
National will also provides large volume manufacturers it's own unique hardwired coding scheme. This unique hardwired coding scheme makes it impossible to generate a signal that can ever be duplicated by another company's remote keyless product.
This variety of HiSec Rolling Code solutions provides an extremely high degree of security while ensuring that the customers engineering efforts are minimal.
Additional Features - The device's functionality in the automobile market goes beyond security. It can be used to control functions such as seat positions, climate control and windows, to name a few. Toward this end, the HiSeC Rolling Code Generator in a 8-pin SO has two programmable keys while in a 14-pin SO, it has four programmable keys. The HiSeC Rolling Code Generator supports either an infrared or radio frequency signal transmitter, and can be clocked with either an RC clock or a crystal oscillator. The device operates over a voltage range of 2.2V to 6.5V, and offers a low power stand-by mode (<1microA) for battery applications. The low power stand-by mode enables more than five years battery life in a typical application.