Apple has asked a US court to
overturn an earlier ruling ordering the company to help the FBI break
into a phone used by one of the San Bernardino killers.
In court
papers Apple says law enforcement authorities are seeking "dangerous
powers" and the move violates its constitutional rights.
The FBI and White House have said the request is limited to one iPhone.
But Apple says the software needed to comply with the FBI's request "simply does not exist".
Instead
Apple says it would have to create a new version on the iPhone
operating software, containing a back door to the device's encrypted
data.
It argues that the lower court did not have the authority to force Apple to do that.
Apple
also says no court had ever forced a company to weaken the security of
its products to gain access to personal individual information.