Unlocking the San Bernardino shooter's iPhone was the FBI's most expensive public hacking job yet

At least as far as we know.

How much does it cost for the federal government to break into an iPhone? More than the head of the Federal Bureau of Investigation makes in seven years, FBI Director James Comey said at conference Thursday.

According to Reuters' calculations, the FBI paid more than $1.3 million to unlock San Bernardino shooter Syed Farook's iPhone — Comey earns $183,000 annually.

"But it was, in my view, worth it," Comey said at the Aspen Security Forum in London.

After investing more than $1.3 million in the project — the most the federal government has ever paid for a publicized hacking contract — the FBI has been able to use its new hardware to break into other iPhone 5Cs.

The federal government paid hackers to find a "previously unknown software flaw" in the iPhone 5Cs that would allow the FBI to access the data on Farook's phone, anonymous sources told the Washington Post earlier in April. The FBI was later able to build hardware to guess Farook's four-digit passcode.

This was part of a long and high-profile fight between Apple and the federal agency, which first ordered Apple to help the FBI unlock the phone. Apple, which has refused to deliberately weaken its encryption feature for the government, has since been taken to court in similar cases to unlock different iPhone versions.

Go deeper:

• Vox's Tim Lee explains the encryption battle between Apple and the FBI.
• WhatsApp, the world's largest communication application, implemented an encryption protocol that makes it impossible to help federal agencies. Here's how.