Google and Apple on Thursday said they are hardening encryption tactics on devices powered by their mobile operating systems and tossing away the keys.
The move should mean that even the government with its court-issued warrants will be blocked from getting hold of pictures, messages and other personal data stored on forthcoming Android or Apple smartphones and tablets.
Google and Apple are among Internet titans intent on firming up trust shaken by revelations of massive online spying by US officials and by the recent hacking of celebrity iCloud accounts that exposed nude photos.
A Google spokesman told AFP that encryption is already offered for the Android system on smartphones and tablets, but will be turned on automatically in the upcoming version of software.
"For over three years Android has offered encryption, and keys are not stored off of the device, so they cannot be shared with law enforcement," the spokesman said in a statement.
"As part of our next Android release, encryption will be enabled by default out of the box, so you won't even have to think about turning it on."
Google has not said when the next update of Android is due for release.
Apple announced that its new encryption is built into the iOS 8 operating system available on the iPhone 6, which goes on sale Friday. It also can be installed on many existing iPhones and iPads.
Apple is essentially allowing people to lock iPhones, iPads or iPods using encrypted passwords without giving itself any keys.
"Your personal data such as photos, messages (including attachments), email, contacts, call history, iTunes content, notes, and reminders, is placed under the protection of your passcode," says the new policy on Apple's website.
"Apple cannot bypass your passcode and therefore cannot access this data. So it's not technically feasible for us to respond to government warrants for the extraction of this data from devices in their possession running iOS 8."
Hall added that the move is "good for the industry because there is a real deficit of trust" after the celebrity photo hacking.
