From Cracker Jack’s box to The Da Vinci Code, everyone is enjoying decrypting secret messages. But biomedical engineers at Duke University took a decoding loop in place that it hadn’t before — the patterns created by bacterial colonies.
Depending on the initial conditions used, such as nutrient levels and space limitations, bacteria tend to grow in specific ways. The researchers created a virtual bacterial colony and then controlled the growth conditions and numbers and sizes of simulated bacterial dots to create a complete alphabet based on how the colonies would look after they filled a virtual Petri dish. They call this the emorfi coding scheme.
The coding is not one-to-one, because the final simulated pattern corresponding to each character is not exactly the same every time. However, the researchers discovered that machine learning software can learn to distinguish between them to recognize the intended letter.
“A friend may see many of my photos over the course of time, but none of them will be completely identical,” explained Lingchong You, a professor of biomedical engineering at Duke. “But if all the pictures consistently enhance what I generally look like, a friend will be able to recognize me even if I show him a picture of me he’s never seen before.”
To encode real messages, the encoder ends up creating a movie of a series of patterns, each associated with a different character. While they may look similar to the untrained eye, a computer algorithm can distinguish them. As long as the receiver knows the initial set of conditions that led to its creation, a hacker should not be able to crack the code without a strong AI of its own.
Try the cypher for yourself. You can write anything from your name to a Gettysburg address, or even the classic Christmas book, “Be sure to drink your glass”:
This research was supported by the National Science Foundation (MCB-1937259), the Office of Naval Research (N00014-20-1-2121), the David and Lucile Packard Foundation, and Google Cloud Research Credits.