The clash between Apple and the FBI is the latest battle in a century-long conflict over the power to keep secrets. The FBI wants Apple to build a “backdoor to the iPhone” so that it can read encrypted data on a locked phone used by one of the San Bernadino attackers.

Apple says such a backdoor would be the equivalent of “a master key, capable of opening hundreds of millions of locks”. Creating such a key, Apple says, would “undermine decades of security advancements”. Cryptography was once controlled by the state, which deployed it for military and diplomatic ends. But in the 1970s, long-haired hippy Whitfield Diffie came up with what has been described as the most revolutionary concept in encryption since the Renaissance. Diffie’s invention took the keys away from the state and marked the start of the ‘Crypto Wars’ – the fight for the right of individuals and companies to communicate beyond the gaze of government agencies. The Inquiry tells the compelling story of the ongoing encryption war, taking evidence from expert witnesses including Whitfield Diffie himself. (Photo: Rally support for Apple refusal to help FBI. Credit: EPA Wires)