It takes a lot of energy to mine popular cryptocurrencies such as bitcoin (BTC). That’s why researchers are working to develop blockchain algorithms that are lighter on the grid.

Bitcoin mining alone uses as much energy as Chile consumes, according to Digiconomist. In the past 12 months, the estimated terawatt hours per year consumed by bitcoin mining has risen from 13.66 TWh to 71.12 TWh, according to the website.

Proof of useful work makes it feasible for large data centers to become miners without dramatically increasing their computing overhead.

Bitcoin and many other popular digital currencies rely on something called a proof-of-work (PoW) model, in which computers on a blockchain compete against one another to solve complex mathematical problems. The one that solves a problem first gets to add a new block containing recent transactions to the chain and is rewarded with freshly “mined” cryptocurrency.

‘Game of Chance’

“In PoW, miners guess values,” Ittay Eyal, an assistant professor at Israel’s Technion and the associate director of the Initiative for Cryptocurrencies & Contracts, tells ThirtyK. “For each value, they calculate a hash function to see whether it’s a legal value. It’s a game of chance.”

Eyal and his colleagues have developed a different approach, however, called proof of useful work (PoUW). In this system, computers can be used for any desired workload such as complex calculations used in scientific research, and they simultaneously contribute their work toward securing a blockchain. Basically, PoUW uses a central processing unit’s (CPU) normal instructions as the puzzle, rather than requiring it to perform additional work.

Proof of useful work makes it feasible for data centers with large quantities of CPUs to become miners without dramatically increasing their computing overhead.

“Miners using PoUW might be doing long tasks for their own goals, such as protein folding or machine learning,” Eyal, the lead developer, explains. “Each machine instruction is accounted for (just like PoW instructions), but is performing useful work. The miner’s computer randomly decides whether any of those instructions results in a legal block.”

To prevent scams, PoUW uses Trusted Execution Environments (TEE) like those created by Intel Software Guard Extension (SGX) chips, which allow applications to set aside private regions of code and data. This ensures that processes execute correctly and confidentially in a protected address space, thus providing hardware-level security against attacks on the host machine.