Dallas Semiconductor introduces the DS3600, a secure battery-backup controller for data protection in point-of-sale terminals. First in a family of secure battery-management products, the DS3600 provides active tamper detection and rapid-erasure key memory. It supports FIPS-140 security levels 3 and 4, and meets the highest requirements of Common Criteria. The DS3600 is packaged in a CSBGA, a preferred choice for certification because no pins are exposed to the outside world so the package is resistant to tampering.

Memory Architecture

The memory architecture on the DS3600 is integrated to secure battery-backup controllers. The proprietary, on-chip nonvolatile SRAM is used for storage of encryption keys. This memory architecture constantly complements the SRAM cells to eliminate the possibility of memory imprinting due to oxide stresses. As a result, this technology prevents the passive detection of data remnants in stressed memory cells. When the DS3600 generates a tamper alarm, the entire 64-byte array is cleared within 100ns. This erasure of data is this fast because the memory's high-speed direct hardwired clearing function and on-chip power source ensure active erasure. Integrated Functions for Comprehensive Tamper Detection and Data Protection it also provides.

The DS3600 has tamper-detection inputs to interface with system voltages, resistive meshes, external sensors, and digital interlocks. Using a low-power operation, it also monitors those components continuously. The device monitors the integrated real-time-clock (RTC) crystal oscillator and will invoke a tamper response if the oscillator frequency falls outside the set threshold. The internal digital temperature sensor has a programmable rate-of-change detector that protects the DS3600's encryption key memory from thermal attacks. The device constantly monitors primary power. In the event of a power failure, an external battery power source is automatically activated to keep the SRAM, RTC, and tamper detection circuitry alive.