When French prosecutors charged Pavel Durov, the chief executive of the messaging app Telegram, with a litany of criminal offenses on Wednesday, one accusation stood out to Silicon Valley companies.

Telegram, French authorities said in a statement, had provided cryptology services aimed at ensuring confidentiality without a license.

In other words, the topic of encryption was being thrust into the spotlight.

The cryptology charge raised eyebrows at U.S. tech companies including Signal, Apple and Meta’s WhatsApp, according to three people with knowledge of the companies. These companies provide end-to-end encrypted messaging services and often stand together when governments challenge their use of the technology, which keeps online conversations between users private and secure from outsiders.

But while Telegram is also often described as an encrypted messaging app, it tackles encryption differently than WhatsApp, Signal and others. So if Mr. Durov’s indictment turned Telegram into a public exemplar of the technology, some Silicon Valley companies believe that could damage the credibility of encrypted messaging apps writ large, according to the people, putting them in a tricky position of whether to rally around their rival.

“If we assume this becomes a fight about encryption, it is kind of bad to have a defendant who looks irresponsible,” said Daphne Keller, who directs the Program on Platform Regulation at Stanford’s Cyber Policy Center.

Encryption has been a long-running point of friction between governments and tech companies around the world. For years, tech companies have argued that encrypted messaging is crucial to maintain people’s digital privacy, while law enforcement and governments have said that the technology enables illicit behaviors by hiding illegal activity.