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Cryptographic authentication chip

Atmel has announced its CryptoAuthentication starter kit. The AT88CK109STK3 is a modular and versatile development kit for the company’s CryptoAuthentication AT88SA102S and AT88SA100S client security devices and AT88SA10HS host security companion IC. The company’s CryptoAuthentication devices are secure authentication ICs that include an embedded SHA-256 engine and 256bit cryptographic key to make them virtually impossible to crack using brute force methods. The starter kit contains all components necessary for evaluation and demonstration of the capabilities of the CryptoAuthentication IC, as well as for developing SHA-256-based security applications on virtually any embedded platform. The kit includes boards with sockets for the AT88SA102S, AT88SA100S and AT88SA10HS CryptoAuthentication ICs, using a SHA-256 algorithm, an AVR-based small profile USB Microbase pre-loaded with demonstration software, and samples of the AT88SA102S, AT88SA100S and AT88SA10HS. The SHA-256 algorithm in the CryptoAuthentication devices authenticates by using a “challenge/response” operation between the microcontroller or host device and client.

The AT88SA102S and AT88SA100S client devices in the SHA-256 starter kit have a unique serial number and an embedded 256bit key that is never exposed. A 63bit customer secret is burned onto the fuses in the device during the manufacturing system configuration, which can never be read. An additional 23 bits of incremental blow fuses can be used, as needed by the customer. At the beginning of an authentication process (for example, unlocking a door or installing an ink cartridge), the host microcontroller reads a serial number from the device. The host microcontroller performs a SHA-256 hash based on the device’s serial number, a random number generated by the host microcontroller, the 256bit key and knowledge of the customer secret from the CryptoAuthentication devices that are also stored in the host. The host then sends the random number to the client as a “challenge”. The AT88SA102S and AT88SA100S client performs their own SHA-256 hash, based on the same information. The resulting digest or “response” is sent back to the host. The host microcontroller compares this response with the SHA-256 digest from its earlier calculation. If they match, the client is deemed to be authentic.