Protecting mobile phones, cameras, portable power tools, and other battery-powered devices, the AT88SA100S CrytpoAuthentication battery challenge/response authentication IC uses a SHA-256 cryptographic engine and a 256-bit key. The IC consumes less than 100 nA. The device ensures replacement batteries meet product standards, with 256 bits of SRAM for key storage, a unique permanent 48-bit serial number, and 88 one-time, user-programmable non-resettable fuses for battery parameter or status information storage. Physical attacks to retrieve the key erases the SRAM memory, rendering the chip useless. Priced at $0.65 in quantities of 1K units.
408-441-0311, www.atmel.com 
For more information, visit www.atmel.com/products/cryptoauthentication