US National Security Agency (NSA) and UK intelligence service GCHQ have cracked the online technology used to encrypt internet services such as banking, medical records and email, according to the latest revelation from US intelligence leaker Edward Snowden’s trove of documents.

The NSA reportedly spends almost A$275m a year on the top secret encryption-breaking program, which is codenamed “Bullrun” in the US and “Edgehill” in the UK, according to the documents published by the Guardian in conjunction with the New York Times and ProPublica.

The encryption techniques used by Google, Facebook and Yahoo (not to mention banks and others supposedly private services) are defeated by powerful supercomputers, as well as “technical trickery, court orders and behind-the-scenes persuasion to undermine the major tools protecting the privacy of everyday communications”.

The NSA and GCHQ insist that the ability to defeat encryption is vital to their core missions of counter-terrorism and foreign intelligence gathering.