Crypto-currency,

works,” Mr. McAfee said in an interview.

Paving the way for government use, DARPA has funded a handful of startups, such as Guardtime Federal and Galois, Inc., to develop blockchain uses for secure communications, as well as potentially everything from weapons systems to files. The work should be completed within a year, Booher said. Some defense contractors are already demonstrating and deploying the blockchain, he said.

Mr. McAfee hopes to take the technology to corporate clients in June, when his 20-person start-up will release a follow-up version of its software-hardware box called Sentinel, due out from the Harrison, New York-based company in mid-February.

UNUSUAL BEHAVIOR

Sentinel will use artificial intelligence to scan for unusual behavior, such as an employee suddenly working late and downloading large files, while the blockchain will track identities of people who should have access to a corporate network — and immediately flag any unauthorized users, ostensibly before they have a chance to do harm.

Homeland Security has given out grants to start- ups like Evernym, Inc. to see if the blockchain could be used to verify identities — data such as the birthdates and citizenship of people undergoing airport checks, or the credentials of first responders.

The functionality could be ready for deployment by the end of 2017, said Drummond Reed, chief trust officer at Evernym. In September, the startup donated some of its intellectual property to Sovrin Foundation, which is developing a way for anyone to verify their digital identity using the blockchain.

“This is the biggest leap forward for cybersecurity infrastructure in 20 years,” Mr. Reed said. — Bloomberg