The end of the smartphone passcode could be at hand, if technology companies have their way.
Apple is said to be planning to introduce an iPhone that can be unlocked by the owner's fingerprint, while other manufacturers are thought to be experimenting with iris scanning and voice recognition.
Speculation about Apple's plans for fingerprint recognition began last summer when the iPhone maker bought biometric security firm AuthenTec for £235 million. Earlier this month, KGI Securities analyst Ming-Chi Kuo said his firm expected the results of that takeover to be revealed this summer with the new iPhone 5S.
He said: "We expect [that] iPhone 5S will have a fingerprint chip under the Home button, improving security and usability."
Samsung has had a "Face Unlock" feature in its phones since last year's Galaxy S3. However, the phone's camera would often unlock if it recognised a photograph of the owner. The firm says the feature has been improved in the Galaxy S4, released in New York last week .
The Galaxy S4, like Apple's iPhone, has voice recognition software but at present it cannot identify a particular person. In future, it's possible that a smartphone could recognise its owner's voice and unlock accordingly.
Many companies are hoping that these security features could soon be used in place of passwords for websites and mobile applications. Instead of having to remember complicated passwords, fingerprint identification would be quicker, easier and more secure.
Earlier this year, in a paper in an engineering journal, two Google security experts outlined plans for an ID ring or smartphone chip that could replace online passwords.
"We’d like your smartphone or smartcard-embedded finger ring to authorize a new computer via a tap on the computer, even in situations in which your phone might be without cellular connectivity," wrote Eric Grosse, Google's vice president of security, and engineer Mayank Upadhyay.