engine - 5:10 pm on Jan 20, 2011 (gmt 0)

Web Images With Expiry Date Encyption [bbc.co.uk]

Help is at hand for anyone who has ever forgotten about embarrassing images they posted to a social network or website. German researchers have created software called X-Pire that gives images an expiration date by tagging them with an encrypted key. Once this date has passed the key stops the images being viewed and copied. Creators plan to levy a small charge to use the tagging system and put a digital lock on digital pictures.

When the viewer encounters an encrypted image it sends off a request for a key to unlock it. This key will only be sent, and the image become viewable, if the expiration date has not been passed.