Apple Inc. loses a patent infringement lawsuit against VirnetX

Apple has lost the latest round of a patent dispute over secure messaging features in its apps that could see the company forced to pay $502m (£354m) in the another twist in an eight year legal battle.

Apple has been found guilty of infringing four different VirnetX patents in the iMessage, FaceTime, and VPN solutions it offers on iPhones and iPads. The legal battle has been protracted, and it involves multiple lawsuits and a dizzying number of appeals.

Since 2010, Apple has been in a patent fight with Internet security software company VirnetX. That's because PTAB believes VirnetX's patents are invalid even for cases now in progress. Apple has been targeted by this twice over the last several years. The case isn't dead yet though, the USA legal system has plenty of room for additional appeals and Apple is exploring those options already. As a result, Apple has been ordered to pay damages to the tune of $502.6 million. Even so, there was still a major difference there, Apple and Samsung both use their patents in products that they make and sell, while VirtnetX focuses on court cases to bring in revenue.

In a statement to Bloomberg, VirnetX CEO Kendall Larsen called the damages amount "fair".

The case is now being reviewed by the Court of Appeals for the Federal Circuit in Washington, which will determine whether or not VirnetX's patents are actually invalid. But it has been speculated that the decision is likely to be scrapped as the Patent Trial & Appeal Board has claimed the patents under investigation to be invalid.

For now, Apple's lawyers aren't commenting and VirnetX is celebrating a victory.