As election day approaches, Republican presidential candidate Donald Trump’s campaign isn’t taking any chances and has started investing in advanced technology to safeguard against cyber breaches.

This move follows a series of successful cyberattacks by Iranian hackers that stole emails and other sensitive data, as well as two assassination attempts on the former president. The campaign has now given staff encrypted mobile phones and secure laptops from military tech supplier Green Hills Software, which claims its devices are “unhackable.”

Green Hills Software claims its technology is immune to intrusion attempts and said it has offered the same solutions to the Democratic presidential candidate Kamala Harris’s campaign.

The customized Android phones provided by the company come pre-installed with Green Hills’ unique operating system, Green Hills Integrity-178B operating system, which is trusted in military applications, including the stealth B-2 bomber and F-35 fighter jets. The OS is one of the few commercially available systems certified at Evaluation Assurance Level 6.

This OS strips the devices of most functions, limiting them to basic phone calls and text messaging, while adding multiple layers of security controls. In addition to this, the phones operate in an isolated communication channel, where only devices on the same plan can interact with each other. The devices also feature default end-to-end encryption and two-factor authentication.

The company attributes its security to tight coding practices and locking down every potential access point, which reduces the chances of a successful hack. Green Hills Software CEO Dan O’Dowd explained the operating system on these devices runs on approximately 10,000 lines of code, which are rigorously tested by a team motivated to uncover vulnerabilities.

“I’ve had staff complaining that they can’t find enough bugs,” O’Dowd remarked.

The campaign also purchased stripped-down laptops designed to be inaccessible from the internet, providing another layer of protection against outside attackers. These laptops follow the same security-first approach as the phones, though, they allow team members to collaborate remotely. Users can access a shared set of files and log in an isolated computing environment.

According to O’Dowd, this technology has been previously used by legal teams working on highly sensitive court cases, where maintaining secure and separate files for clients was a top priority. He added that the technology is also used by FBI field offices.