Analog Devices DS28E25 Product Info

• Symmetric-Key-Based Bidirectional Secure Authentication Model Based on SHA-256
• Dedicated Hardware-Accelerated SHA Engine for Generating SHA-256 MACs
• Strong Authentication with a High Bit Count, User-Programmable Secret, and Input Challenge
• 4096 Bits of User EEPROM Partitioned Into 16 Pages of 256 Bits
• User-Programmable and Irreversible EEPROM Protection Modes Including Authentication, Write and Read Protect, and OTP/EPROM Emulation
• Unique, Factory-Programmed 64-Bit Identification Number
• Single-Contact 1-Wire Interface Communicates with Host at Up to 76.9kbps
• Operating Range: 3.3V ±10%, -40°C to +85°C
• Low-Power 5µA (typ) Standby
• ±8kV HBM ESD Protection (typ)
• 2-Pin SFN, 2-Pin TO-92, 6-Pin TDFN, and 6-Pin TSOC Packages

DeepCover™ embedded security solutions cloak sensitive data under multiple layers of advanced physical security to provide the most secure key storage possible.

The DeepCover Secure Authenticator (DS28E25) combines crypto-strong, bidirectional, secure challengeand- response authentication functionality with an implementation based on the FIPS 180-3-specified Secure Hash Algorithm (SHA-256). A 4Kb user-programmable EEPROM array provides nonvolatile storage of application data and additional protected memory holds a readprotected secret for SHA-256 operations and settings for user memory control. Each device has its own guaranteed unique 64-bit ROM identification number (ROM ID) that is factory programmed into the chip. This unique ROM ID is used as a fundamental input parameter for cryptographic operations and also serves as an electronic serial number within the application. A bidirectional security model enables two-way authentication between a host system and slave-embedded DS28E25. Slave-to-host authentication is used by a host system to securely validate that an attached or embedded DS28E25 is authentic. Hostto-slave authentication is used to protect DS28E25 user memory from being modified by a nonauthentic host. The SHA-256 message authentication code (MAC), which the DS28E25 generates, is computed from data in the user memory, an on-chip secret, a host random challenge, and the 64-bit ROM ID. The DS28E25 communicates over the single-contact 1-Wire^® bus at overdrive speed. The communication follows the 1-Wire protocol with the ROM ID acting as node address in the case of a multiple-device 1-Wire network.

Applications

• Authentication of Network-Attached Appliances