Siddharth Garg, assistant professor of electrical and computer engineering at the New York University's Tandon School of Engineering and fellow researchers are developing a chip with both an embedded module that proves that its calculations are correct and an external module that validates the first module's proofs.
While software viruses are easy to spot and fix with downloadable patches, deliberately inserted hardware defects are invisible and act surreptitiously.
For example, a secretly inserted "back door" function could allow attackers to alter or take over a device or system at a specific time.
Garg's configuration, an example of an approach called "verifiable computing" (VC), keeps tabs on a chip's performance and can spot telltale signs of Trojan viruses.
Under the system proposed by Garg and his colleagues, the verifying processor can be fabricated separately from the chip.
The chip designer then turns to a trusted foundry to build a separate, less complex module: an ASIC (application-specific integrated circuit), whose sole job is to validate the proofs of correctness generated by the internal module of the untrusted chip.
According to Garg, this arrangement provides a safety net for the chip maker and the end user.
"Under the current system, I can get a chip back from a foundry with an embedded Trojan. It might not show up during post-fabrication testing, so I'll send it to the customer," Garg noted in a university statement.
"But two years down the line, it could begin misbehaving. The nice thing about our solution is that I don't have to trust the chip because every time I give it a new input, it produces the output and the proofs of correctness, and the external module lets me continuously validate those proofs," he explained.
An added advantage is that the chip built by the external foundry is smaller, faster, and more power-efficient.
In 2015, a gift of $100 million from Indian-American couple Chandrika and her husband Ranjan Tandon resulted in the school changing its name to the Tandon School of Engineering.
