Now, in the age of the smartphone, Boeing is developing a real-life device that deletes all its call and message data if any unauthorized attempt is made to crack it open.
Boeing's device is one of two stealthy new "Black phones" that were revealed this week, both targeting privacy-sensitive customers who want to hide below the radar of the growing surveillance of mobile communications.
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Boeing already runs secure communications for the U.S. president's Air Force One aircraft and is pitching its device at government officials and their contractors.
Meanwhile, start-up Silent Circle, in a Swiss-based joint venture, is hoping to tap growing demand among consumers and enterprises for extra protection from prying eyes, in the wake of privacy revelations by Edward Snowden, the former NSA contractor.
Despite Boeing's hopes of keeping its device's development in "stealth mode", details of its Black phone emerged on Wednesday in regulatory filings published by the Federal Communications Commission.
"Boeing has developed its Black phone primarily by governmental agencies and their contractors to ensure that data and voice communications undertaken by their respective employees are transmitted and stored in a highly secure manner," it said in a letter requesting confidential treatment of the device through the communications regulator's review process.
The details of the device are "highly sensitive" and any employees or customers who handle it are required to sign non-disclosure agreements, Boeing said.
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Sealed with epoxy resins and screws covered with tamper-proof coating, any attempt to break open Boeing's Black phone would "trigger functions that would delete the data and software contained within the device and make the device inoperable", added the letter. "Any attempted servicing or replacing of parts would destroy the product."
The other Blackphone, launched this week at the Mobile World Congress and the cyber security conference RSA, already has orders from about 20 of the Fortune 50. The iPhone look-a-like encrypts all calls, messages and files, as well as coming loaded with privacy-focused apps for functions such as search.
Like any other Android phone, users can download whatever apps they like in the Google Play app store but the Blackphone tells them what data the app is collecting about them and how far they can change the settings to prevent it.
Mike Janke, chief executive and co-founder of Silent Circle, which developed the smartphone with Spanish manufacturer Geeksphone, said the handset was just the "first flag in the ground" for a whole series of products.
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The pair is already developing a Blackphone Two and has its eyes on creating a privacy-focused tablet as well. Mr Janke said it wanted to build a community of young tech entrepreneurs who wanted to make apps with privacy protections.
"There's a new generation of software developers that are thinking: 'I can actually charge a dollar for this product with 30 million users and then not sell ads'," he said.
Ethan Oberman, co-founder and chief executive of Spider Oak, a privacy-focused cloud storage company, said he was looking forward to creating more products for the Blackphone ecosystem.
"Since the Snowden revelations there has been a groundswell in the developer market with people creating privacy-focused products that have not hit the market yet. The app store can connect them with us," he said.
In recent days, Apple was forced to rush out a patch for a newly discovered flaw in its iPhone and Mac software that allowed customers' data to be intercepted over unsecured WiFi networks.