DS28E25

ABRIDGED DATA SHEET EVALUATION KIT AVAILABLE DS28E25 DeepCover Secure Authenticator with 1-Wire SHA-256 and 4Kb User EEPROM General Description 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-tohost authentication is used by a host system to securely validate that an attached or embedded DS28E25 is authentic. Host-to-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, ...