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DS28EL25 Datasheet, PDF (1/6 Pages) Maxim Integrated Products – DeepCover Secure Authenticator with 1-Wire SHA-256 with 4Kb User EEPROM
ABRIDGED DATA SHEET
EVALUATION KIT AVAILABLE
DS28EL25
DeepCover Secure Authenticator
with 1-Wire SHA-256 with 4Kb User EEPROM
General Description
DeepCoverK embedded security solutions cloak sensi-
tive data under multiple layers of advanced physical secu-
rity to provide the industry’s most secure key storage pos-
sible. The Deepcover Secure Authenticator (DS28EL25)
combines crypto-strong, bidirectional, secure challenge-
and-response authentication functionality with an imple-
mentation based on the FIPS 180-3-specified Secure
Hash Algorithm (SHA-256). A 4Kb user-programmable
EEPROM array provides nonvolatile storage of applica-
tion data and additional protected memory holds a read-
protected 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 num-
ber within the application. A bidirectional security model
enables two-way authentication between a host system
and slave-embedded DS28EL25. Slave-to-host authenti-
cation is used by a host system to securely validate that
an attached or embedded DS28EL25 is authentic. Host-
to-slave authentication is used to protect DS28EL25 user
memory from being modified by a nonauthentic host. The
SHA-256 message authentication code (MAC), which the
DS28EL25 generates, is computed from data in the user
memory, an on-chip secret, a host random challenge,
and the 64-bit ROM ID. The DS28EL25 communicates
over the single-contact 1-WireM 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
Printer Cartridge ID/Authentication
Reference Design License Management
System Intellectual Property Protection
Sensor/Accessory Authentication and Calibration
Secure Feature Setting for Configurable Systems
Key Generation and Exchange for Cryptographic
Systems
Features
S Symmetric Key-Based Bidirectional Secure
Authentication Model Based on SHA-256
S Dedicated Hardware-Accelerated SHA Engine for
Generating SHA-256 MACs
S Strong Authentication with a High Bit Count, User-
Programmable Secret, and Input Challenge
S 4096 Bits of User EEPROM Partitioned Into 16
Pages of 256 Bits
S User-Programmable and Irreversible EEPROM
Protection Modes Including Authentication, Write
and Read Protect, and OTP/EPROM Emulation
S Unique, Factory-Programmed 64-Bit Identification
Number
S Single-Contact 1-Wire Interface Communicates
with Host at Up to 76.9kbps
S Operating Range: 1.8V ±5%, -40°C to +85°C
S Low-Power 5µA (typ) Standby
S ±8kV Human Body Model ESD Protection (typ)
S 6-Pin TDFN Package
Typical Application Circuit
1.8V
(I2C PORT)
µC
RP
VCC
SDA
SCL
DS24L65
RP = 820Ω
MAXIMUM I2C BUS CAPACITANCE 400pF
1-Wire LINE
SLPZ
IO
DS28EL25
Ordering Information appears at end of data sheet.
1-Wire is a registered trademark and DeepCover is a trademark
of Maxim Integrated Products, Inc.
For related parts and recommended products to use with this part, refer to: www.maximintegrated.com/DS28EL25.related
For pricing, delivery, and ordering information, please contact Maxim Direct at
1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.
219-0022; Rev 0; 12/12