Zoom Video Communications Inc. has been lambasted for its security flaws, but the backlash hasn’t slowed growth. The company reported a 50 per cent surge in use of the online meeting application in the past three weeks.

On April 21, more than 300 million people used Zoom’s flagship videoconferencing app, up from about 200 million on April 1, Chief Executive Officer Eric Yuan said Wednesday during a webinar focused on security. While some companies and school districts have dropped the app, Zoom’s response has reassured investors and sent shares climbing.

“Clearly the Zoom platform is providing an incredibly valuable service to our beloved users during this challenging time,” Yuan said. “We are thrilled and honored to continue to earn the trust of so many enterprises, hospitals, teachers and customers throughout the world.”

Zoom’s shares rose about 5 per cent Wednesday to US$150.25 at the close of New York trading. The stock has more than doubled so far this year. Before the Covid-19 pandemic, Zoom was focused on business communications and used by about 10 million people, mostly office workers.

The San Jose, California-based company earlier Wednesday detailed a variety of updated security measures for the latest version of its app, including the ability to report a user to Zoom and a boosted level of encryption. Like many of its peers, the company doesn’t offer end-to-end encryption, which is the highest standard.