Scientists read a 300-year-old sealed letter without opening it

To open the letter

Scientists are using “letterlocking” to read sealed centuries-old letters.

Nature Communications

The contents of a handwritten European letter sealed for Years0000 will no longer be secret, thanks to technology that allowed scholars to look inside virtually without damaging a complexly constructed historical document.

In a letter dated July 31, 1697, Jacques Cenacox requested a certified copy of the death notice for his cousin Pierre Le Purse, a French merchant in The Hague, for Daniel Le Purse. It is not a revelation to make history, but the technique of disclosing the request promised to unlock sealed correspondence containing historical gems at the time and place.

All of these years ago, Senacax’s letter was discontinued using a process called “letterlocking”, a complex folding technique used globally to secure a post before the discovery of envelopes. Think of it like ancient encryption: Letters sealed in this way cannot be opened without being torn, and RIPs indicate that the note was tampered with before reaching the intended recipient.

“Letterlocking has been a daily activity across cultures, boundaries and social classes for centuries,” said Jana Dembrogo, author of a paper published Tuesday in the Thomas F. Peterson Conservator of MIT Libraries and Journal of Nature Communications. Unlocking technique.

No paper was damaged in reading this letter: it came out virtually.

Nature Communications

Before the age of modern digital cryptography, letter locking played an integral role in securing physical communications. Some early letterlocking examples can be found in the Vatican Secret Archives of 1494. The researchers would have just torn the letter open, but they wanted to save all its folds and parts, which is similar to the evidence about the communication transaction.

“This research takes us to the heart of a locked letter,” Dumbrogrio said in a statement.

To unlock the letter, an interdisciplinary team of researchers from MIT and King’s College Lodge London turned to advanced X-ray machines designed for dentistry designed to produce high-resolution 3D scans that showed how the paper was arranged. An automated calculation algorithm developed by a former and current MIT student produces vivid images of the letter material and intricate crease patterns.

“Virtual disclosure is a computational process that analyzes CT scans of folded letterpackets and creates a pinch image of their contents,” the team said. “Our Virtual Revealed Pipeline produces a 3D reconstruction of the folded character, with the corresponding 2D reconstruction representing its flat position and flat images of both surfaces … and the craze pattern of each letterpacket.”

Counting algorithms have been successfully applied to scrolls, scans of books and documents with one or two folds. But the complexity of the letterlock documents raised their own challenges.

The letter comes from the Brian Collection, a European postmaster’s wooden trunk containing 14,188 items, including 7,577 letters that were never unlocked. The research team has unlocked many letters using their new technology and believes it promises many more unopened letters.

“An important example is that the Price Papers contain hundreds of unopened items in 160,000 urgent letters, a collection of documents seized by the British from enemy ships between the 17th and 19th centuries.” “If this can be read without opening the body, very rare letterlocking data can be saved.”

Prior to the researchers’ computational analysis, they only knew the name of the intended recipient on the outside of the locked letter.

“When we got back the first scan of the letter packets, we were immediately hooked up,” said Amanda Khasi, who helped write the code available to the public to make the characters virtually public. “Sealed characters are very interesting and objects, and these examples are especially interesting because special care has been taken to keep them safe.”

Let the history of the letter be revealed.

Corinne Risher of CNET contributed to this report.