MIT researchers have built a new chip
MIT researchers have built a new chip hardwired to perform public-key encryptionMIT

In what could be a major development in the technology world, researchers from Massachusetts Institute of Technology (MIT) have built a new chip that will enable public-key encryption to work in the internet of things (IoT).

Public-key cryptography is a type of encryption that uses pairs of keys – public keys and private keys – wherein any person can use the public keys to encrypt a message but the private keys are known only to the owner. It performs authentication, where the public key verifies the owner of the paired private key; and encryption, where the owner of the paired private key decrypts the message encrypted by using the public key. So, most web transactions are protected by public-key cryptography because it lets computers share information securely.

But public-key encryption protocols are executed by software and won't work in IoT. Why? The reason is IoT is a network that connects many sensors to the online server but the sensors embedded in appliances, buildings, vehicles etc don't have enough energy (battery) and storage for software to execute encryption protocols.

In a big breakthrough, researchers at MIT have built a new chip equipped with the ability to perform public-key encryption to overcome this hurdle. The new chip "consumes only 1/400 as much power as software execution of the same protocols would" and "uses about 1/10 as much memory and executes 500 times faster," according to MIT News.

Samsung DRAM Chip
[Representational picture]

The researchers, led by the author of the paper Utsav Banerjee, an MIT graduate student in electrical engineering and computer, have used a technique called elliptic-curve encryption for the new chip. It is a technique used by most public-key encryption systems but what sets the new chip developed by MIT researchers apart is that it has been designed to "handle any elliptic curve" while other chips are "hardwired to handle specific elliptic curves."

"Cryptographers are coming up with curves with different properties, and they use different primes," said Banerjee. "There is a lot of debate regarding which curve is secure and which curve to use, and there are multiple governments with different standards coming up that talk about different curves. With this chip, we can support all of them, and hopefully, when new curves come along in the future, we can support them as well."

The paper said that the modular multiplier in the chip developed by MIT can handle 256-bit numbers, adding that "eliminating the extra circuitry for integrating smaller computations both reduces the chip's energy consumption and increases its speed." The researchers also "equipped their chip with a special-purpose inverter circuit" that reduces the power consumption by half while increasing the chip's surface area by 10 percent.

The MIT researcher's chip also comes with technology that reduces the amount of memory required for execution of encryption protocol.