Researchers Read Sealed Renaissance-Era Letter Without Opening It!

Emily Moulin
2021-03-17T11:36:12-07:00

On July 31, 1697, a French lawyer named Jacques Sennacques wrote an urgent message to remind a cousin in the Netherlands to send him a relative's death certificate. To prevent others from reading the confidential memo, the note was carefully folded, or "letter locked." The ancient technique, which transformed the letter into its own secure package, was prevalent before the invention of envelopes.