Last year, after founding a startup that uses blockchain technology to protect against cyberattacks, three University of Maryland students behind Gladius Network LLC went looking for investors.

Through their lawyer at the firm Paul Hastings, they met the head of an Israeli marketing firm, who would connect them to Krypton Blockchain Holdings, the Ukrainian company focusing on investments in startups that use blockchain technology. At Gladius, the three founders were optimistic about a possible partnership, and the feeling appeared to be shared, according to court papers. The company’s technology promised to deflect so-called denial-of-service attacks, redirecting malicious web traffic across a decentralized network of computers.