1997-06-06 , E/IC-829/260

The effectiveness of the software-based security schemes offered by many of today's smart card controllers is already being questioned by service providers, particularly for transaction handling over public networks such as the Internet. At the same time, the smart card industry is looking to the concept of 'open' cards that can be used for a wide range of authorisation, identification and transaction purposes. As always, a short time-to-market for new designs remains the key to maximising revenue.

With the introduction today of its new family of 16-bit SMART_XA microcontrollers, Philips Semiconductors meets all three requirements - by providing a firewall-hardware-protected and multi-tasking smart card controller architecture that executes downloaded high-level programs, for example written in Java, yet can still be programmed using software expertise and library components derived from existing 8-bit card designs.

SMART_XA controllers are true 16-bit machines offering around 30 times the processing power of 8-bit 80C51-derivative smart card controllers running at the same clock speed, yet if necessary, they can still be programmed using 80C51 code. This not only means that developers can take advantage of existing software libraries, but also means they can use development tools they are familiar with. For programs written in high-level languages (HLLs) such as C or Java the SMART_XA's high execution speed and efficient memory usage minimise all the normal disadvantages of using compiled code. Its HLL-optimised instruction set makes it possible to implement an on-card interpreter that can efficiently run downloaded C or Java programs for example in a multi application environment.

Unlike 80C51-based smart card controllers, SMART_XA controllers offer a fully hardware-protected multi-tasking software environment with full exception handling and an impenetrable firewall that provide the ultimate defence against attacking secure data contained on the controller's on-chip memory. This unique firewall effectively provides the programmer with two virtual machines - one in which resident or downloaded application programs can be run in a secure environment, and a second protected machine that prevents any two applications from interfering with one another. Comprehensive protection of the memory segments allocated to each downloaded program provides complete security against fraudulent program modifications that might otherwise eavesdrop on another application's data or even the operating system code.

In addition to protecting the memory space allocated to each application, the SMART_XA architecture includes on-chip low and high voltage sensors on the supply rails and low and high frequency sensors on its clock input that disable the chip when it is forced outside normal operating conditions. This prevents attacks to the on-chip data by forcing the device into an illegal operating state. Other in-built security features include electronic fuses for safeguarded write access control, and a clock independent erase/write timing for the on-chip EEPROM.

High-security public key cryptography algorithms are supported by the SMART_XA controllers' on-chip FAMEX (Fast Accelerator for Modular Exponentiation - Extended) crypto co-processor. Capable of computing complex RSA signatures with key-lengths in excess of 2048 bits in a few hundred milliseconds, this crypto accelerator meets the dual requirements of extremely high security for card communication and fast response.

SMART_XA controllers are low-power, low-voltage CMOS devices with power-down and sleep modes that suit them for use in cards for portable systems. Chip reliability has been dramatically enhanced by incorporating an I_DDQ test method that detects early failures during manufacture by looking for anomalies in the chip's quiescent supply current.

Fully upward compatible with the existing broad range of 80C51-based solutions, SMART_XA controllers are supported by a variety of existing development tools as well as new tools such as those being jointly developed by Philips and Ashling Microsystems.

Philips Semiconductors, a division of Philips Electronics NV, headquartered in Eindhoven, The Netherlands, is the ninth largest semiconductor supplier in the world and already has a remarkable 40% share of the total 80C51 microcontroller market - with the largest number of derivative products based on the 80C51 architecture. Sales offices are located in all major markets around the world and are supported by systems labs.

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