Elderly patients or those with chronic diseases are increasingly able to monitor their condition from home or other convenient locations because their vital signs and test results can be sent over the Internet to their physicians. But as this becomes standard practice, patient confidentiality is an increasing concern. At RMIT University, in Melbourne, Australia, scientists are working on a way to hide a patient’s private data in plain sight. The technique, published last month in IEEE Transactions on Biomedical Engineering, uses steganography, the practice of embedding secret information inside a larger bit of innocuous data without noticeably affecting the size or character of the larger data. (Steganography—such as hiding a message in an image file—was famously used by a Russian spy ring caught in the United States in 2010.) In the research, the technology conceals identifying patient information so it can only be accessed by healthcare workers who have the correct credentials. Its inventors demonstrated it using electrocardiogram (ECG) signals but the researchers hope that it will be applicable for use with various medical monitoring devices. “It can hide a picture of a person, it can hide personal details of the person, and it can also contain information about who can look at the ECG,” says Ibrahim Khalil, a computer scientist at RMIT and one of the study’s two authors.