The encoder could also be used to reveal a security code on a credit card. Image: NDAO Lab

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A team of engineers at the University of California San Diego (UCSD) have developed a humidity-based image encoder that looks straight out of James Bond’s Q-Lab . The postage stamp-sized chip can store a hidden message that is only revealed when exterior humidity levels surpass 60 percent. The image can then be concealed again by bringing humidity back down.…