After the social-media start-up Kik Interactive sold $100 million worth of digital “coins” in 2017, the Canadian company argued that it didn’t need the permission of federal securities regulators.

On Tuesday, those regulators begged to differ. The Securities and Exchange Commission sued Kik in federal court in Manhattan, claiming that its sale of a digital currency — in the form of a digital token it called Kin — to investors was unlawful because it had not been registered with the government.

The court battle could help determine the S.E.C.’s authority to regulate aspects of the cryptocurrency industry, which has expanded far beyond the digital currency Bitcoin. Companies have sold self-branded digital coins or tokens to raise money, something the S.E.C. has said violates securities laws.

“Kik deprived investors of information to which they were legally entitled, and prevented investors from making informed investment decisions,” Steven Peikin, the S.E.C.’s co-head of enforcement, said. “Companies do not face a binary choice between innovation and compliance with the federal securities laws.”