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The 16th-century codebreaker who wrote secret messages on boiled eggs

• warrenm 3y ago
  >His first rather startling and brilliant contribution to the art of code-making was the ingenious means by which messages might be smuggled to prisoners via eggs. This might sound whimsical, but this was still the time of the Inquisition, and to be suspected of heresy could be hideously dangerous. Secret messages that made it past the most intensive searches could be life-saving for many prisoners kept in dungeons. But how to avoid this stringent security? The method: write the message, using alum or plant dye, onto the shell of an egg. When the egg is dry, hard-boil it and the message on the shell will disappear. The egg could then be taken into the prison in a package of food. When it arrived, all the recipient had to do was peel the shell and they would find the message there, indelibly soaked onto the boiled egg white.