US Defense Secretary Pete Hegseth is facing intense scrutiny following revelations that he accessed the encrypted messaging app Signal via an unsecured internet connection in his Pentagon office — a move that has sparked concerns over potential breaches in cybersecurity protocols.

According to an Associated Press report citing two officials familiar with the matter, Hegseth used a so-called “dirty” internet line — a direct and unfiltered connection to the public internet — on a personal computer inside his official workspace. The existence of such a line, which lacks the Department of Defense’s standard security filters, raises serious questions about adherence to established cybersecurity measures.

While Signal’s end-to-end encryption is designed to prevent interception, experts note that using an unclassified and unsecured line from within the Pentagon could have exposed sensitive national security information to hacking or surveillance by foreign actors.

A senior US official with knowledge of military network infrastructure told AP that such lines are typically avoided in high-security environments. “The main advantage is anonymity — the user blends in with the sea of civilian internet traffic. But that comes at a steep cost: vulnerability to adversarial monitoring and a lack of proper federal recordkeeping compliance,” the official said.

The controversy deepened after reports emerged that Hegseth had shared details about a recent military airstrike in two Signal group chats. One of these reportedly included family members, while the other involved senior national security officials from former President Donald Trump’s administration.

A separate report by The Washington Post first disclosed Hegseth’s use of Signal, prompting a terse response from the Pentagon. Spokesman Sean Parnell said, “The Secretary’s communication methods are classified. However, we can confirm that the Secretary has never used and does not currently use Signal on his government computer.”

Sources say the fallout from the revelations has already led to internal reshuffling at the top levels of the Defense Department. Several of Hegseth’s advisers have reportedly been reassigned or dismissed, adding to the growing perception of a shrinking and embattled inner circle.

Despite mounting bipartisan concerns on Capitol Hill, the White House continues to stand by the embattled defense chief. “It’s just fake news. They just bring up stories,” said former President Trump, dismissing the criticism during a recent press briefing.

Vice President JD Vance also defended Hegseth, stating on Wednesday, “I have 100% confidence in the Secretary. I know the President does, and really, the entire team does.”

However, calls for greater transparency and adherence to federal cybersecurity guidelines continue to grow, with several lawmakers demanding an independent review of internal communication practices within the Pentagon.