What Signal Is, and Why It Was Not Intended for War Rooms

The Pentagons recent report highlights a crucial fact: while Signal provides strong privacy for messages, it was never intended for transmitting U.S. military plans. Using it in this manner posed real risks to American personnel.

Signals Purpose

Signal is a globally popular encrypted messaging application, widely used by journalists, activists, aid workers, and privacy-focused individuals. Key features include:

• End-to-end encryption for calls, messages, video, and attachments
• Minimal metadata storage, meaning messages are not saved on Signal servers
• Open-source cryptography, allowing independent security audits
• Nonprofit operation without advertisements or data harvesting

For everyday users, Signal is a robust privacy tool. Organizations like the Freedom of the Press Foundation consistently rank it among the most secure apps for civilian communication. However, this does not make it suitable for classified military communications.

Why Signal Is Not Fit for Military Use

The main misconception is equating encryption with authorization for official military planning. Department of Defense (DoD) guidelines clearly restrict sensitive communications to approved systems. Signals leadership has emphasized that the app is meant for public privacy, not classified government work.

Signal was designed to protect civilians from surveillance, not to meet the Pentagons strict operational security, classified transmission, or record-keeping standards. Relevant regulations include:

• DoDI 8100.04: Only DoD-approved communication systems may handle DoD information.
• DoDI 5200.48: Controlled Unclassified Information cannot be sent via unapproved apps.
• DoD CIO mobile guidance: Commercial apps may risk unauthorized disclosure of non-public information.
• Federal Records Act: Official messages must be preserved, which Signals auto-deletion prevents.

In short, sending operational details via a personal device on a commercial app violates military communication policies. This is the basis for the inspector generals findings.

The Origin of Signalgate

The controversy began in March 2025, when senior officials involved in U.S. operations against Houthi forces in Yemen used Signal for coordination. A journalist was accidentally added to the chat, exposing details such as aircraft numbers and strike timing. Screenshots and transcripts later became publicly available, revealing sensitive operational information.

Findings of the Pentagon Watchdog

The Department of Defense inspector generals final report, released on December 3, 2025, concluded:

1. Non-public operational information was shared via Hegseths personal phone using Signal.
2. Signal was not authorized for classified communications, violating DoD rules.
3. These actions endangered U.S. personnel and missions.
4. Required records were not preserved due to auto-deletion and off-system storage.
5. Investigators had limited access to devices and relied on public transcripts and screenshots.

Signals Security vs. Military Requirements

Signal is highly secure for civilian messaging, offering strong encryption and minimal data retention. However, military operational security demands:

• Controlled servers
• DoD-managed networks
• Auditing and record retention
• Classified communication channels
• Device-level protections and chain-of-custody assurances

Signal lacks these capabilities by design, making it unsuitable for sensitive military communications. The issue lies not with the app itself, but with its use for classified operations.

Implications for Service Members

The case reinforces long-standing rules: operational or sensitive information must never be shared via personal devices or commercial apps. Encryption alone does not equate to authorization, and personal devices remain potential vulnerabilities. While no disciplinary action was recommended for Hegseth, the report serves as a clear reminder that operational security rules apply at all levels.

Author: Gavin Porter