This story of Moxie Marlinspike, the developer responsible for a number of privacy-enhancing applications such as the one recently added to WhatsApp, is quite the fascinating read:

Mr. Marlinspike created an encryption program that scrambles messages until they reach the intended reader. It’s so simple that Facebook Inc.’s WhatsApp made it a standard feature for many of the app’s 800 million users.

The software is effective enough to alarm governments. Earlier this year, shortly after WhatsApp adopted it, British Prime Minister David Cameron called protected-messaging apps a “safe space” for terrorists. The following week, President Barack Obama called them “a problem.”

That makes the lanky, dreadlocked and intensely private coder a central figure in an escalating debate about government and commercial surveillance. In a research paper released Tuesday, 15 prominent technologists cited three programs relying on Mr. Marlinspike’s code as options for shielding communications.

His encrypted texting and calling app, Signal, has come up in White House meetings, says an attendee. Speaking via video link last year as part of a panel on surveillance, former National Security Agency contractor Edward Snowden, who leaked troves of U.S. spying secrets, urged listeners to use “anything” that Mr. Marlinspike releases.