The eye-popping scandal surrounding the Trump cabinet’s accidental invitation to The Atlantic’s editor in chief to join a text-message group secretly planning a bombing in Yemen has rolled into its third day, and that controversy now has a name: SignalGate, a reference to the fact that the conversation took place on the end-to-end encrypted free messaging tool Signal.

As that name becomes a shorthand for the biggest public blunder of the second Trump administration to date, however, security and privacy experts who have promoted Signal as the best encrypted messaging tool available to the public want to be clear about one thing: SignalGate is not about Signal.

Since The Atlantic’s editor, Jeffrey Goldberg, revealed Monday that he was mistakenly included in a Signal group chat earlier this month created to plan US airstrikes against the Houthi rebels in Yemen, the reaction from the Trump cabinet’s critics and even the administration itself has in some cases seemed to cast blame on Signal for the security breach. Some commentators have pointed to reports last month of Signal-targeted phishing by Russian spies. National security adviser Michael Waltz, who reportedly invited Goldberg to the Signal group chat, has even suggested that Goldberg may have hacked into it.

On Wednesday afternoon, even President Donald Trump suggested Signal was somehow responsible for the group chat fiasco. “I don’t know that Signal works,” Trump told reporters at the White House. “I think Signal could be defective, to be honest with you.”

The real lesson is much simpler, says Kenn White, a security and cryptography researcher who has conducted audits on widely used encryption tools in the past as the director of the Open Crypto Audit Project: Don’t invite untrusted contacts into your Signal group chat. And if you’re a government official working with highly sensitive or classified information, use the encrypted communication tools that run on restricted, often air-gapped devices intended for a top-secret setting rather than the unauthorized devices that can run publicly available apps like Signal.

“Unequivocally, no blame in this falls on Signal,” says White. “Signal is a communication tool designed for confidential conversations. If someone’s brought into a conversation who’s not meant to be part of it, that’s not a technology problem. That’s an operator issue.”

Cryptographer Matt Green, a professor of computer science at Johns Hopkins University, puts it more simply. “Signal is a tool. If you misuse a tool, bad things are going to happen,” says Green. “If you hit yourself in the face with a hammer, it’s not the hammer’s fault. It’s really on you to make sure you know who you’re talking to.”

The only sense in which SignalGate is a Signal-related scandal, White adds, is that the use of Signal suggests that the cabinet-level officials involved in the Houthi bombing plans, including secretary of defense Pete Hegseth and director of national intelligence Tulsi Gabbard, were conducting the conversation on internet-connected devices—possibly even including personal ones—since Signal wouldn’t typically be allowed on the official, highly restricted machines intended for such conversations. “In past administrations, at least, that would be absolutely forbidden, especially for classified communications,” says White.

Indeed, using Signal on internet-connected commercial devices doesn’t just leave communications open to anyone who can somehow exploit a hackable vulnerability in Signal, but anyone who can hack the iOS, Android, Windows, or Mac devices that might be running the Signal mobile or desktop apps.

This is why US agencies in general, and the Department of Defense in particular, conduct business on specially managed federal devices that are specially provisioned to control what software is installed and which features are available. Whether the cabinet members had conducted the discussion on Signal or another consumer platform, the core issue was communicating about incredibly high-stakes, secret military operations using inappropriate devices or software.

One of the most straightforward reasons that communication apps like Signal and WhatsApp are not suitable for classified government work is that they offer “disappearing message” features—mechanisms to automatically delete messages after a preset amount of time—that are incompatible with federal record retention laws. This issue was on full display in the principals’ chat about the impending strike on Yemen, which was originally set for one-week auto-delete before the Michael Waltz account changed the timer to four-week auto-delete, according to screenshots of the chat published by The Atlantic on Wednesday. Had The Atlantic’s Goldberg not been mistakenly included in the chat, its contents might not have been preserved in accordance with long-standing government requirements.

In congressional testimony on Wednesday, US director of national intelligence Tulsi Gabbard said that Signal can come preinstalled on government devices. Multiple sources tell WIRED that this is not the norm, though, and noted specifically that downloading consumer apps like Signal to Defense Department devices is highly restricted and often banned. The fact that Hegseth, the defense secretary, participated in the chat indicates that he either obtained an extremely unusual waiver to install Signal on a department device, bypassed the standard process for seeking such a waiver, or was using a non-DOD device for the chat. According to political consultant and podcaster FP Wellman, DOD “political appointees” demanded that Signal be installed on their government devices last month.

Core to the Trump administration’s defense of the behavior is the claim that no classified material was discussed in the Signal chat. In particular, Gabbard and others have noted that Hegseth himself is the classification authority for the information. Multiple sources tell WIRED, though, that this authority does not make a consumer application the right forum for such a discussion.

“The way this was being communicated, the conversation had no formal designation like ‘for official use only’ or something. But whether it should have been classified or not, whatever it was, it was obviously sensitive operational information that no soldier or officer would be expected to release to the public—but they had added a member of the media into the chat,” says Andy Jabbour, a US Army veteran and founder of the domestic security risk-management firm Gate 15.

Jabbour adds that military personnel undergo annual information awareness and security training to reinforce operating procedures for handling all levels of nonpublic information. Multiple sources emphasize to WIRED that while the information in the Yemen strike chat appears to meet the standard for classification, even nonclassified material can be extremely sensitive and is typically carefully protected.

“Putting aside for a moment that classified information should never be discussed over an unclassified system, it’s also just mind-boggling to me that all of these senior folks who were on this line and nobody bothered to even check, security hygiene 101, who are all the names? Who are they?” US senator Mark Warner, a Virginia Democrat, said during Tuesday’s Senate Intelligence Committee hearing.

According to The Atlantic, 12 Trump administration officials were in the Signal group chat, including vice president JD Vance, secretary of state Marco Rubio, and Trump adviser Susie Wiles. Jabbour adds that even with ​​decisionmaking authorities present and participating in a communication, establishing an information designation or declassifying information happens through an established, proactive process. As he puts it, “If you spill milk on the floor, you can’t just say, ‘That’s actually not spilled milk, because I intended to spill it.’”

All of which is to say, SignalGate raises plenty of security, privacy, and legal issues. But the security of Signal itself is not one of them. Despite that, in the wake of The Atlantic’s story on Monday, some have sought tenuous connections between the Trump cabinet’s security breach and Signal vulnerabilities. On Tuesday, for example, a Pentagon adviser echoed a report from Google’s security researchers, who alerted Signal earlier this year to a phishing technique that Russian military intelligence used to target the app’s users in Ukraine. But Signal pushed out an update to make that tactic—which tricks users into adding a hacker as a secondary device on their account—far harder to pull off, and the same tactic also targeted some accounts on the messaging services WhatsApp and Telegram.

“Phishing attacks against people using popular applications and websites are a fact of life on the internet,” Signal spokesperson Jun Harada tells WIRED. “Once we learned that Signal users were being targeted, and how they were being targeted, we introduced additional safeguards and in-app warnings to help protect people from falling victim to phishing attacks. This work was completed months ago.”

In fact, says White, the cryptography researcher, if the Trump administration is going to put secret communications at risk by discussing war plans on unapproved commercial devices and freely available messaging apps, they could have done much worse than to choose Signal for those conversations, given its reputation and track record among security experts.

“Signal is the consensus recommendation for highly at-risk communities—human rights activists, attorneys, and confidential sources for journalists,” says White. Just not, as this week has made clear, executive branch officials planning airstrikes.

Updated at 5:50 pm ET, March 25, 2025: Added remarks about Signal by President Trump.