Secure Device Architecture

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 Secure Device Architecture

Security in Microsemi Flash FPGAs

Until the advent of the Microsemi families of flash-based FPGAs there was no secure reprogrammable logic technology available for embedded systems designers. While antifuse is the most secure of all programmable logic solutions because of the difficulty associated with trying to copy or reverse engineer the contents of a design, flash-based FPGAs with FlashLock have the advantage of reprogammability and security.

Microsemi FlashLock

The Microsemi FlashLock advantage prevents unauthorized users from being able to read back the contents of an Microsemi flash FPGA. In addition to the inherent strengths of the architecture, special security keys are hidden throughout the fabric of the device, preventing internal probing and overwriting. They are located such that they cannot be accessed or bypassed without destroying the rest of the device, making both invasive and more subtle noninvasive attacks ineffective against Microsemi flash FPGAs.

A ProASIC3 and ProASIC^PLUS flash cell cross section is shown above. Determining the state of a single switch is difficult, as microprobing the switch will destroy the charge on the floating gate. To determine the state of millions of switches is prohibitive. In addition, the uniform (homogenous) nature of flash FPGAs makes it difficult to identify probe points during invasive attacks.

Security in Microsemi Antifuse FPGAs

Industry experts regard antifuse as the most secure of all programmable logic solutions because of the difficulty associated with trying to copy or reverse engineer the contents of a design. Because of this, antifuse FPGAs have long been used by the military and other OEMs, who demand the highest security available. Microsemi's presence and rich tradition in these markets is a powerful testimonial to the merit of Microsemi's products for customers who value security.

Determining the state of a single switch is difficult, to determine the state of millions is prohibitive.

Secure Against Reverse Engineering

A number of factors complicate attempts to compromise an Microsemi antifuse FPGA. The microscopic size and sheer number of antifuse make it essentially impossible to locate each fuse and identify its programming state. For example, a single AX2000 FPGA from Microsemi contains approximately 53,000,000 antifuses with only 2-5% programmed in an average design. Invasive probing to evaluate each fuse would most likely result in the destruction of the programmed states needed to trace the design.

The Industry's Leading Nonvolatile Single-Chip FPGA Solution

Once programmed, the device is inherently nonvolatile, which allows the device to retain its configuration indefinitely without requiring an external configuration device. This means that there is no bitstream susceptible to interception, eliminating the potential for in-system errors or data erasures that might occur during download.

Microsemi FuseLock

The Microsemi FuseLock advantage ensures that unauthorized users will not be able to read back the contents of an Microsemi antifuse FPGA. In addition to the inherent strengths of the architecture special security fuses that prevent internal probing and overwriting are hidden throughout the fabric of the device. They are located such that they cannot be accessed or bypassed without destroying the rest of the device, making both invasive and more-subtle noninvasive attacks ineffective against Microsemi antifuse FPGAs.