Scientists have come up with a novel way to encode biological messages on physical objects using genetically-engineered bacteria that react to light or chemicals to reveal hidden codes.

Using a technology enterprisingly dubbed ‘Steganography of Printer Arrays of Microbes’ (SPAM), the team at Tufts University in Massachusetts have published a paper that explains how seven different photo-sensitive strains of Escherichia Coli bacteria could fuse biology with information science, or infobiology for short.

In order to demonstrate the principle the team first engineering bacteria containing fluorescent proteins (FPs) sensitive to different wavelengths of light and then created patterns from the resulting info-bacteria.

By encoding characters using two colours per character, this allowed for an alphabet of up to 49 possibilities, enough to use the system for basic alpha-numeric messages.

The security application is the potential for secrecy. Because messages are being encoded in a biological medium, it is possible to make them invisible until certain conditions are met, including the passing of time or a reaction with a specific chemical such as an anti-biotic.

If the bacteria are considered the encryption mechanism this turns the chemical into the encryption key, which could be any from a large number of possibilities. Importantly, because the bacteria are literally microscopic finding them on an object would be almost impossible, offering intriguing possibilities in terms of security applications.

It’s unlikely that the system would be used in place on conventional encryption – it doesn’t essentially do anything that can’t be done more easily with today’s conventional electronic designs – but it could perhaps be used to brand the authenticity of merchandise in a way that would be hard to bypass.

"You could put the cipher code in an undiscoverable location on the packaging, and the array itself in a protected part of the casing. That way, the receiver can authenticate a delivery to make sure it hasn't been tampered with," Tufts team leader Professor David Walt told media outlets.

“We haven’t thought out all the different applications yet. We could put a time-encoded message so things develop at different times, so you could have one message initially and then another. Or you could have a self-destructing message like in [1970’s TV show] Mission Impossible,” he said.

Other applications of bacterial infobiology include barcoding and biometrics.

Infobiology isn't a new as it sounds - two years ago IBM suggested a way in which the DNA molecule could be used as part of a new type of microprocessor design.