IC Blocks Illegal Battery Packs March 2005 Issue Published Date: March 09, 2005
Exploiting the Secure Hash Algorithm (SHA-1) as per Federal Information Publication 180-1/2 and ISO/IEC 10118-3, the DS2703 authentication IC employs a challenge/response scheme to authenticate battery packs found in a range of portable products. Integrating the device in a battery pack allows the host to guard against unauthorized packs that could introduce unknown functions or substandard operation. Via a 64-bit key and unique 64-bit ROM ID, its SHA-1 engine processes a 64-bit host-transmitted challenge to produce a 160-bit response word for transmission back to the host. The key is stored on-chip and never transmitted between the battery and the host. To save space and allow the use of just three contacts between the battery pack and host, the device integrates a thermistor multiplexer. The data and thermistor contact also serves as the power line to the device, which derives power through a one-wire interface. Available in an 8-pin microSOP, prices start at $0.77 each/10,000. DALLAS SEMICONDUCTOR, Dallas, TX. (800) 998-8800.
