National Security Agency whistleblower Edward Snowden announced Thursday that he is working with the prominent hacker Andrew “Bunnie” Huang to create a cellphone hardware that would protect journalists from government surveillance. The device, dubbed “introspection engine,” would be a plastic case designed to slide over an Apple iPhone 6, and will monitor the phone’s internal antennas to detect incoming and outgoing signals from the cellular, Bluetooth, Wi-Fi or GPS chips, alerting users of any snooping attempt.

“The introspection engine has the capability to alert a reporter of a dangerous situation in real-time. The core principle is simple: if the reporter expects radios to be off, alert the user when they are turned on,” Snowden and Huang said in a technical write-up released Thursday. ecommerce services “The introspection engine will be an open source, user-inspectable and field-verifiable module attached to an existing smart phone that makes no assumptions about the trustability of the phone’s operating system.”

The device would come with a small mono-color screen that will flash an alert when it detects a transmission that shouldn't be taking place. According to Snowden and Huang, the device, by maintaining a constant check on whether the cellphone's radios are transmitted, is a much more effective way of blocking unauthorized signals than a phone's "aiplane mode" — which can be hacked or spoofed.