Reports have surfaced that Apple is looking to ditch its current passcodes system for iPhones, replacing it with an image recognition system.
The technology, if implemented, would show a random picture of one of the owner's contacts and ask for their name from a list on the touchscreen or via voice recognition.
Apple said that the current system is too easily circumvented by thieves: "Users sometimes misplace their handheld devices or inadvertently leave them in public places.
"To dissuade thieves from stealing handheld devices (or people from accessing their friends' devices), many software manufacturers require a user to provide input that 'unlocks' the handheld device. Such input may be a passcode of four or more characters."
"However, this approach for authenticating a user can be easily compromised.”
Apple explained: "For example, a thief sitting on a bus may notice the four characters that an unsuspecting person entered on the person's smart phone. As another example, a thief may pick up a tablet computer in a public place and discover, based on finger prints on the display of the tablet computer, which characters were recently selected by the owner of the tablet computer."
Apple has also said that the new system might not necessarily be based on identifying people. For example, a picture of the Golden Gate Bridge could be associated by the iPhone owner with the digits 5341 because they are the last digits of the phone number of someone they met there.
"Thus, '5341' must be entered whenever that image is displayed as part of the authentication process," it said.
Apple applied to protect the idea in 2011, which was published by the US Patent and Trademark Office this week.