DS1207

• Cannot be deciphered by reverse engineering
• Time allotment from one day to 512 days for trial periods, rentals, and leasing
• Partitioned memory thwarts pirating
• User-insertable packaging allows personal possession
• Exclusive blank keys on request
• Appropriate identification can be made with a 64-bit reprogrammable memory
• Unreadable 64-bit match code virtually prevents discovery by exhaustive search with over 1019 possibilities
• Random data generation on incorrect match codes obscures real accesses
• 384 bits of secure read/write memory create additional barriers by permitting data changes as often as needed
• Rapid erasure of identification, security match code and secure read/write memory can occur if tampering is     detected
• Durable and rugged
• Applications include software authorization, gray market software protection, proprietary data, financial    transactions, secure personnel areas, and system access control

The DS1207 TimeKey is a miniature security system that stores 64 bits of user-definable identification code and a 64-bit security match code that protects 384 bits of read/write nonvolatile memory. The 64-bit identification code and the security match code are programmed into the TimeKey via a special program mode operation. After programming, the DS1207 follows a procedure with a serial format to retrieve or update data. The TimeKey is set to expire from one day to 512 days or infinity, as specified by the customer. The DS1207 starts its countdown from the first access by the end user.

Interface cost to a microprocessor is minimized by on-chip circuitry that permits data transfer with only three signals: Clock (CLK), Reset (RST) and Data Input/ Output (DQ). Low pin count and a guided entry for a mating receptacle overcome mechanical problems normally encountered with conventional integrated circuit packaging, making the device transportable and user-insertable.