As the White House comes under fire for allegedly using Signal to discuss sensitive foreign policy plans, the encrypted messaging platform has now come into the spotlight.
Although the government has officially discouraged federal employees from using the app for official business, it has become a crucial tool for many businesses, tech enthusiasts and the public for sharing messages securely.
Signal was launched in 2014 for iOS devices by a non-profit group, Open Whisper Systems, which offered users free encrypted calls and one year later, encrypted instant messaging. Encryption disguises data and information so that only those who send and receive the messages can read them.
An Android version of the app launched in 2015. Both versions are free to download in the app stores.
A mobile device displays the Signal company logo while a laptop displays the webpage of the messaging app, on March 25, 2025.
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“Signal is designed to never collect or store any sensitive information. Signal messages and calls cannot be accessed by us or other third parties because they are always end-to-end encrypted, private, and secure,” the company said on its website.
Representatives from Signal Technology Foundation, the parent non-profit that operates the app, didn’t immediately respond to ABC News’ request for comment.
The app registers users through their phone numbers, similar to WhatsApp and iMessage, and provides several options, including disappearing messaging and protection from screenshotting messages. Signal has touted that it does not give user data to corporations and other entities.
Encryption keys for Signal messages are stored on the user’s devices and not on its servers.
The apps grew in popularity among smartphone users and have been promoted by various figures in the tech community, including Edward Snowden.
A mobile device displays the Signal company logo while a laptop displays the webpage of the messaging app, on March 25, 2025.
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Despite its growth, U.S. government officials have been wary of members using the app for official business.
The Pentagon’s internal watchdog criticized a former official’s use of the Signal app in 2021, calling it a breach of the department’s “records retention policies” and an unauthorized means of communicating sensitive information.
The report, which focused on Brett Goldstein, a former director of the Defense Digital Service, found that Goldstein violated department policies by using Signal “to discuss official DoD information” and encouraging subordinates to communicate with him on the encrypted messaging app.
“Signal is not approved by the DoD as an authorized electronic messaging and voice-calling application,” the report asserted, adding that “the use of Signal to discuss official DoD information does not comply with Freedom of Information Act requirements and DoD’s records retention policies.”
Goldstein had already announced his plans to depart government service by the time the report was published. According to the report, Goldstein lobbied the department’s legal office to allow him to use the app.
“We recommend that the Secretary of Defense take appropriate action regarding Mr. Goldstein’s use of the unauthorized electronic messaging and voice-calling application,” the report concluded.
During a Senate Intelligence Committee hearing Tuesday, Democratic Sen. Mark Warner grilled CIA Director John Ratcliffe about his participation in the Signal chat. Ratcliffe said he was in the chat, but claimed many in the agency are approved to use Signal.
“One of the first things that happened when I was confirmed as CIA director was Signal was loaded onto my computer at the CIA as it is for most CIA officers. One of the things that I was briefed on very early senator, was by the CIA records management folks about the use of Signal as a permissible work use. It is that is a practice that preceded the current administration to the Biden administration,” Ratcliffe testified under oath.
Ratcliffe, and the other intelligence officials who testified, did not provide more details about the government’s use of the app or approvals to use it.
As of 2024, the app has 70 million users worldwide compared to the 12 million who used it in 2020, according to the app tracking site Business of Apps.
In 2023, the non-profit, which is funded through donations and a $50 million investment in 2017 from WhatsApp co-founder Brian Acton, said in a blog post it required $50 million a year to operate in 2025.
“Our goal is to move as close as possible to becoming fully supported by small donors, relying on a large number of modest contributions from people who care about Signal. We believe this is the safest form of funding in terms of sustainability: ensuring that we remain accountable to the people who use Signal, avoiding any single point of funding failure, and rejecting the widespread practice of monetizing surveillance,” the company said.
ABC News’ Luke Barr, Cherise Halsall and Nathan Luna contributed to this report