Dallas—Dallas Semiconductor's DS2705 is a SHA-1 authentication master that provides the master side of a secure hash algorithm-based (SHA) token authentication scheme and orchestrates the challenge/response sequence. This dedicated device, for use in digital cameras, portable DVD and media players, cradle and accessory chargers, and cell
phones/smartphones, eliminates the hardware and software development of a host implementation, thus greatly simplifying design efforts and reducing development time.
Residing within the host, the DS2705 works with the company's other battery-management SHA-1 token products that reside in the battery or accessory. These latter products include the DS2703 SHA-1 battery-pack authentication IC and the DS2704 1280-bit EEPROM with SHA-1 authentication.
Authentication with the DS2705 can be configured to initiate upon host demand or automatically when a battery or accessory is inserted into a system. The predetermined SHA-1 challenge-and-response pair is
stored in the DS2705's nonvolatile EEPROM, which can be permanently locked to prevent corruption. Upon completion of the challenge-and-response sequence between the master and token, the pass/fail status is reported on dedicated DS2705 port pins (one pin for pass and one for fail) to signal the charge system
and/or drive LEDs. All communication between the DS2705 master and the SHA-1 token product proceeds through the company's 1-Wire interface.
Click here for the device datasheet. The device, in an 8-pin micro SOP or micro MAX lead-free package, is priced starting at $2.20 each (10k-up,
Maxim Integrated Products, 1-800-998-8800, www.maxim-ic.com