TAIPEI — eMemory Technology, the world’s seventh-largest IP vendor, expects its physically unclonable function (PUF) technology to continue the company’s strong growth as security issues in the semiconductor industry become a higher priority.

PUFs are semiconductor fingerprints, unique physical properties inherent in silicon structures that can be used to identify individual chips. eMemory says its NeoPUF technology protects hardware at the chip level by generating unique IDs and crypto keys from those fingerprints.

The integration of NeoPUF into a chip design helps to prevent unauthorized code execution and data reads, according to the company. At a time when concerns have grown surrounding the vulnerability of CPUs and other chips in systems for IoT and point of sales (POS), eMemory expects its new technology to help continue its 40 percent compound annual growth rate in royalties and licensing over the past 12 years.

“Once you have the chip fingerprint, there are a lot of applications,” said eMemory Chairman Charles Hsu in an interview with EE Times. “For example, authentication. You can use the chip fingerprint and a number to set a secret key. You can use this secret key to encrypt your data before you send it out. The most important thing is every system has its own number. If a system is hacked into, only one system is compromised, not all of the systems.”

eMemory Chairman Charles Hsu
eMemory Chairman Charles Hsu sees numerous security applications for new PUF technology (Photo: Alan Patterson)

A common solution for chip security uses eFuse technology with a secret key for identification, authentication and encryption. The secret key comes from a third-party provider, which eMemory sees as a potential security risk.

“Our invention is that we can generate the random number on the chip itself,” according to Hsu. “And each chip has its own random number, so it’s not managed by anybody.”

eMemory’s PUF technology uses the hardware fingerprint on a chip to create a random number that eliminates the need to store a secret key. The number for each chip is regenerated regularly by the hardware to prevent hacker attacks.

“The beauty of this solution is the key is not stored outside the system,” says eMemory Director Li-Jeng Chen.

Security Issues
One example of a chip-security issue that eMemory believes it can solve is the rampant counterfeiting of processors. The problem has become serious enough that the U.S. Defense Advanced Research Projects Agency (DARPA) has created the Supply Chain Hardware Integrity for Electronics Defense (SHIELD) program.

SHIELD aims to combine NSA-level encryption, sensors, near-field power and communications into a microscopic-scale chip capable of being inserted into the packaging of a chip. The 100 micrometer x 100 micrometer "dielet" will act as a hardware root of trust, detecting any attempt to access or reverse engineer the dielet, according to DARPA.

Worldwide, there are 7.5 billion counterfeit chips, according to Hsu.

One backdoor vulnerability in CPUs is predictive execution, where some outcome is predicted and execution proceeds along the predicted path until the actual result is known.

The problem occurs when the prediction is wrong, and the predicted command is executed, storing key data in the register. When the next command is executed, the data that has been stored is susceptible to a hack.

“If everything is encrypted by the chip, even with predictive execution, the stored data is encrypted and more difficult to hack,” Hsu says.

eMemory’s existing non-volatile memory IP is currently used in all of the world’s leading foundries such as Taiwan Semiconductor Manufacturing Co. (TSMC) and Global Foundries. eMemory’s NeoPUF IP extends the company’s patented technology to provide security that’s incorporated on a chip without adding any mask layers to an existing design, according to Hsu.

eMemory’s non-volatile memory is very different from conventional non-volatile memory (NVM) like NAND flash or NOR flash, which are made with a special process, according to Hsu. The company has focused on creating an NVM without changing commonly used logic processes. eMemory has created IP for one-time programmable, multiple-time programmable and EEPROM devices. The EEPROM device can be rewritten for one million cycles.

“They all use a logic process that’s our invention,” Hsu says.

(source: eMemory)

Security Drawbacks
If everything needs to be encrypted and decrypted, that takes time.

“There’s always a tradeoff between security and performance,” says Hsu. To ameliorate the problem, encryption and decryption should be made very simple, he says.

Compared with other versions of PUF in the market, eMemory believes that its solution provides superior performance. One example Hsu offers is SRAM PUF.

With SRAM PUF, every time a system powers on, the secret key needs to be changed, so it always requires error code correction (ECC). Supporting data also needs to be restored.

Every time the power comes on, the ECC needs to correct the data, Hsu says. Once ECC is added into a security circuit, it slows down system performance a lot, he adds.

NeoPUF doesn’t need ECC, so processing time is reduced significantly, Hsu says. The company declined to provide specific numbers on performance comparisons due to variables related to the amount of helper data and algorithms used for ECC in SRAM PUF.

Hsu says he has recently visited a lot of IC companies, and he believes that system companies are more concerned about security than the IC makers.

Among the chipmakers that are interested in security are those who are working on AI, according to Hsu.

“The most important thing for AI is algorithms,” Hsu says. “You have to protect your algorithms. You spend all this research money to develop this method, but if someone just copies it, everything is gone.”

FPGAs are being used for AI, and they include firmware used in the gate arrays.

“They have to protect it,” Hsu says. “They are very strong users of security.”

Emerging Applications
eMemory also sees potential for NeoPUF in IoT devices.

“Once you can provide effective security, IoT can take off, Hsu says.”

In March, a Taiwan-based company that designs radio-frequency chips will launch a product using eMemory’s security key-generating IP. eMemory declined to publicly disclose the company name, citing customer confidentiality. The customer will use eMemory’s PUF technology to safeguard key technology on its chips.

Another customer plans to use NeoPUF on their secure digital (SD) controller product, according to eMemory.

eMemory says it has met a U.S.-based POS systems maker that wants to design its own chips and likes the eMemory security solution. eMemory also sees potential with a number of Chinese companies making POS machines.

Some security concerns involve design engineers who store a number on a chip secretly, says eMemory Director Chen.

“If some of these engineers leave their company, they can take the secret numbers with them. The best way is for the chip to generate such numbers on its own.”

Company History
Before founding eMemory in 2000, Chairman Hsu was a professor at Tsing Hua University in Hsinchu, Taiwan’s Silicon Valley. Prior to becoming a professor, Hsu worked at the IBM Watson Research Center in the U.S. There, he found out about logic devices that can be programmed easily.

Hsu says he did a lot of research on non-volatile memories while he was at the university. Following that, he and a few of his students decided to go into business and successfully did fundraising.

One of their key efforts was building a patent portfolio, and the company now has more than 500 patents.

(Source: eMemory)

Through a partnership with Taiwan memory maker Powerchip and Japan’s Mitsubishi, eMemory started designing a one-time programmable memory for Mitsubishi as a substitute for mask ROM on microcontrollers that would eliminate mask layers in the fabrication process.

Today, eMemory is still collecting royalties from Renesas, which the former semiconductor division of Mitsubishi is a part of. The product today has made more than NT$10 billion ($340 million) in royalties.

“When this product first came out, we thought it could be used with microcontrollers. But it turned out that there are a lot of uses for it,” Hsu says. “Not only microcontrollers. LCD drivers, power management, sensors and so on.”

It turned out that the applications for that first IP far exceeded what Hsu originally imagined.

eMemory today has 250 employees, mainly from Taiwan’s leading technology universities. The company says it has had no problem attracting employees and has even convinced people from TSMC to join their ranks.

—Alan Patterson covers the semiconductor industry for EE Times. He is based in Taiwan.