In the world of espionage, privacy and security are top priorities to the success and safety of secret agents. Over the centuries, spies have utilized an evolving series of techniques to maintain the privacy of their confidential information.

In Roman times, authors of secret information tinkered with plant extracts to make invisible ink, and that clandestine art was used well into modern times. However, such inks remained invisible only until heat, special lights or chemical solutions were used, and that fact also made the information available to clever enemies.

Although cryptography and encryption furnished modern society with new ways to make information private, these security methods also became vulnerable to the clever adversary in this age of advanced computer technology.

Scientists now have found a new method to encrypt information in much the same way as the Enigma machine allowed the German army in World War II to encrypt and decrypt messages without fear of interception. Comprised of a series of rotors that produced a code, the sender could use the Enigma to encrypt a message and send it by radio. Only a recipient who knew the initial rotor settings could decrypt the message using their own Enigma machine. The discovery and eventual decoding of the German Enigma machine by Allied powers became a major factor in defeating the German Empire.

Presently, researchers are working with cryptography to synthesize specific chemicals that serve as highly secure passwords based on their atomic composition to produce a sort of chemical Enigma system.

In this case, the chemical Enigma system consists of a fluorescent amino acid structure (elemental components of various proteins) that can bind to various other compounds. With this “chemical device system,” the sender converts a message into a code, such as each letter representing a number, and dissolves that message into a specific chemical solution.

All the recipient of that message needs to do is add the same chemical and solvent as the sending device to produce the conditions which decrypt the message—much like a recipient in the past used the same rotor settings on the Enigma machine to reproduce readable text.

To be able to read this special chemically dissolved message with this molecular technique, a spy only needs to add the same chemical and solvent to produce a fluorescence emission to decipher the code and receive the message.

What all this technical jargon boils down to is that someone can hide a message within the molecular chemical sensor in a solution and allow that liquid to absorb into something like paper or cloth, and another person (another spy) could soak the paper or cloth in a liquid with the same chemical configuration to unlock the ciphered text, which is then read with special cryptography.

I can envision a spy using a very simple eyedrop solution to drip a message onto a napkin and that would allow another spy to easily retrieve that napkin, dissolve it in a solution and then decode the message. 

What makes this spy tool so advantageous is that there are so many chemical compounds available that can be fluoresced to hide a message within a chemical compound. The important key is that both the encryptor and the decryptor must know the secret chemical reaction required to allow the message to be retrieved.

Scientists believe there are large numbers of compounds available that could be chosen for the reaction sequence. The important key is that the chemical methodology to encrypt and decrypt should be applied with molecules that have a high level of structural complexity, and the chemical process should be simple, robust and predictably reproducible.

As a final layer of security, the chemicals used should be as thermally and chemically inert as possible—what scientists call “a one-pot reaction” to unlock the chemically-imbedded message.

I think I have the beginnings of a plot for a new short story here!

Thoughts? Comments? I’d love to hear them!