I've been saying this for years. Encryption is math. Not in theory. Not in abstract. In real practice. Encryption is math. To make encryption illegal—as 75% of US politicians, from both parties, including President Obama, want to do—is literally saying "if you do this math, we will put you in prison." It's no less absurd than when Indiana tried to pass a law declaring π to be 3.2. It's insanity. Liberty notwithstanding, it is unequivocal madness. No lunatic's tyranny can change that.
It's also bullshit in a country where the power of government is rooted in the citizenry and not in the authority of the government itself. In a system of law where innocence is presumed, the government has no right to require that all communications can be made public at some future date.
All verbal conversations that are unrecorded are encrypted for all intents and purposes.