QR codes, those goofy black-and-white arrangements of digital information, could help secure bank notes. Scientists just showed that they could print an invisible QR code made of a high-tech ink ...

eWeek content and product recommendations are editorially independent. We may make money when you click on links to our partners. Learn More Xerox said on Wednesday that its scientists have perfected ...

Invisible ink is back, and it’s better at hiding than ever. A new invisible ink that you can print is harder to reveal than most common cyphers. Liang Li at Shanghai Jiao Tong University in China and ...

Researchers have developed a rewriteable paper coating that can encrypt secret information with relatively low-tech invisible ink -- water. A message printed out by a water-jet printer on a ...

A water soluble carbon nanodot ink produces bright long lasting invisible prints with micrometer scale detail and high accuracy for secure and low cost applications. Fluorescent inks fade quickly ...

If you’ve got a spare printer ink cartridge and a document you only want one person to see—or just some free time and a cloak-and-dagger kick—one helpful Metacafe post has a project for you. The ...