Battery Authentication IC uses SHA-256 cryptographic engine.

Press Release Summary:




Supporting supply voltage of 2.5-5.5 V, AT88SA100S CrytpoAuthentication(TM) IC protects mobile phones, portable power tools, cameras, and other microcontroller-based products from counterfeit battery packs. Device has 256 bits of SRAM for key storage, 48-bit serial number stored permanently inside, and 88 one-time user-programmable fuses for storage of battery parameters or status information. Removing CryptoAuthentication chip from battery erases SRAM memory, rendering chip useless.



Original Press Release:



Atmel Introduces Low Power Cryptographic Battery Authentication IC with SHA-256



SRAM-based key storage ensures keys are permanently destroyed if IC is removed from battery

San Jose, CA, July 8, 2009 - Atmel® Corporation (Nasdaq: ATML) announced today its AT88SA100S ultra low-cost, cryptographic battery authentication IC for mobile-phones, cameras, portable power tools, and other battery-powered applications.

The AT88SA100S CrytpoAuthentication(TM) IC is the only battery authentication IC that uses a SHA-256 cryptographic engine and a 256-bit key that cannot be cracked using brute force methods. It is used to protect mobile phones, portable power tools, cameras, and other microcontroller-based products from counterfeit battery packs.
Counterfeit batteries are often less expensive than those provided by the original equipment manufacturer (OEM) because they often do not have appropriate protective mechanisms to prevent short circuits, abnormal heat or leakage, ignition, rupture and other malfunctions. They also are likely to lose their charge sooner and wear out more quickly than authentic battery packs.

Many battery pack vendors typically use holograms or labels to identify their products. These are easily duplicated, and there is big money to be made by counterfeiting them. With unit sales of 3.1 billion, ($7.2 billion) in 2008 and 80% growth expected in the next five years, counterfeiting battery packs is a growth market. It is estimated that 75% of the replacement batteries sold are clones.

The AT88SA100S ensures replacement batteries meet the product manufacturer's standards by providing secure, reliable authentication that can be used to prevent product operation and/or charging with counterfeit product.

The AT88SA100S has 256-bits of SRAM for key storage, a guaranteed unique 48-bit serial number stored permanently inside the chip and 88 one-time, user-programmable fuses that can be used for the storage of battery parameters or status information. The 256-bit key is stored in the on-chip SRAM at the battery manufacturer's site and is powered by the battery pack itself. Physical attacks to retrieve the key are very difficult to effect because removing the CryptoAuthentication chip from the battery erases the SRAM memory, rendering the chip useless.

The fuses, once burned, cannot be reset, providing additional security. There are 80 fuses which can be written individually and can always be read, plus an additional 8 fuses which are used to lock the fuse array in 16-bit increments. Additional non-burnable fuses contain the manufacturing ID and a guaranteed unique 48-bit serial number, initialized by Atmel. The device has a high speed single wire interface that is compatible with all microcontrollers, supports a wide supply voltage range of 2.5V to 5.5V, an even wider 1.8V to 5.5V communications range.

Challenge/response Authentication.

Battery authentication is based on a "challenge/response" protocol between the microcontroller in the portable end-product (host) and the CrytpoAuthentication IC in the battery (client).

When a replacement battery is connected to an end-product, the AT88SA100S sends its serial number to the host microcontroller in the end product. The host performs a SHA-256 hash based on the AT88SA100S' serial number, an internally generated random number and the 256-bit key that resides in the host end-product. The end-product sends the random number to the CryptoAuthentication device on the battery as a "challenge". The CryptoAuthentication IC performs its own SHA-256 hash, based on the random number, its own serial number and the 256-bit key stored in its SRAM. The resulting digest, or "response", is sent back to the end-product and compared with the SHA-256 digest from its earlier calculation. If the two values match, the circuit to the battery is completed and the end-product can begin operating. If the two digests don't match, the product is prevented from operating. The SHA-256 calculation is so sensitive to the original information that changing even a single bit will result in a completely different value.

Since the end-product generates a new random number challenge each time the battery is replaced, intercepting the challenge/response pair being sent over the bus is useless. A new response, based on a different random number, is generated for every transaction. Since the key is unreadable and is never transmitted, it is always secure in the AT88SA100S CryptoAuthentication IC. Removing the AT88SA100S from the battery pack also removes power from the internal SRAM where the key is stored, completely erasing the keys.

Ultra-low Power Consumption.

Since battery packs are changed infrequently, the AT88SA100S spends 99.99% of its time in ultra low-power sleep mode power, consuming less than 100 nanoamps (nA), much less than the normal leakage current of the battery.

Easy System Integration.

In order to speed system design, Atmel provides complete ARM®- and AVR®-compatible source code libraries that implement all necessary cryptographic modules for performing the host-side authentication capability. The AT88SA100S requires only a single GPIO pin on the host processor and only three wires on the connector to the battery, plus a standard bypass capacitor for a low overall BOM impact.

Pricing and Availability.

The AT88SA100S battery authentication IC is available now in production quantities in a 3mm2, green-compliant (exceeds RoHS) 3-pin SOT-23 package. Priced at $0.65 in quantities of 1K units, it is 40% to 60% less expensive than any other battery-authentication IC on the market.

About Atmel.

Atmel is a worldwide leader in the design and manufacture of microcontrollers, advanced logic, mixed-signal, nonvolatile memory and radio frequency (RF) components. Leveraging one of the industry's broadest intellectual property (IP) technology portfolios, Atmel is able to provide the electronics industry with complete system solutions focused on consumer, industrial, security, communications, computing and automotive markets.

© 2009 Atmel Corporation. All Rights Reserved. Atmel®, Atmel logo and combinations thereof, AVR® and others, are registered trademarks, CryptoAuthentication(TM) and others are trademarks of Atmel Corporation or its subsidiaries. ARM® is a registered trademark of ARM Ltd. Other terms and product names may be trademarks of others.

Information: http://www.atmel.com/products/cryptoauthentication

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