The latest filing in the legal war between the planet’s most powerful government and its most valuable company gave one indication of how the high-stakes confrontation could escalate even further.
In what observers of the case called a carefully calibrated threat, the Justice Department last week suggested that it would be willing to demand that Apple turn over the "source code" that underlies its products as well as the so-called "signing key" that validates software as coming from Apple.
Together, those two things would give the government the power to develop its own spying software and trick any iPhone into installing it. Eventually, anyone using an Apple device would be unable to tell whether they were using the real thing or a version that had been altered by officials to be used as a spy tool.
Technology and security experts said that if the U.S. government was able to obtain Apple's source code with a conventional court order, other governments would demand equal rights to do the same thing.
"We think that would be pretty terrible," said Joseph Lorenzo Hall, chief technologist at the nonprofit Center for Democracy & Technology.
The battle between Apple and the U.S Justice Department has been raging since the government in February obtained a court order demanding that Apple write new software to help law enforcement officials unlock an iPhone associated with one of the shooters in the December attack in San Bernardino, California that killed 14 people.
Apple is fighting the order, arguing that complying with the request would weaken the security of all iPhones and create an open-ended precedent for judges to make demands of private companies.
The Justice Department's comments about source code and signing keys came in a footnote to a filing last week in which it rejected Apple's arguments. Apple's response to the DOJ brief is expected on Tuesday.
Justice Department lawyers said in the brief that they had refrained from pursuing the iOS source code and signing key because they thought “such a request would be less palatable to Apple. If Apple would prefer that course, however, that may provide an alternative that requires less labor by Apple.”