Unlock sealed letters over 300 years old

Before envelopes became popular in the 1930s, most letters in the world were sent using letter locks – a method of folding letters so that it became the envelope of the letter itself.

Using computational tools, researchers can virtually open a complicated folded letter from 1697. These are complex techniques to help recipients detect if a message has been tampered with. To date, scientists say letters over 300 years old can be read without opening. Read letters using algorithm During research at the Vatican Secret Archives, conservator Janaa Dambrogio at the MIT Library (Massachusetts Institute of Technology in America) unearthed Renaissance letters with strange cuts and angles. . She found these were signs that they were initially locked with a sliding paper slot and sealed with wax. Such letters cannot be opened without tearing the letter – which helps the recipient to see if the letter has been read or not. After studying 250,000 ancient letters, Dambrogio and her colleagues invented the first system for classifying key-lettering techniques. This is a type of periodic table based on how to crease pages. “Mail lock is 10 thousand years old technology and since people try to secure their mail, gradually they have come to know the key features of mail lock” – Ms. Dambrogio said. Until now, scientists have only read these letters by cutting them out and often corrupting the letters. Although such work naturally focuses on the content of the letter, it is also important to research the letter lock. Dambrogio and her colleagues have devised a way to both read the locked letter’s text without opening it, while at the same time reconstructing the intricate folds and gaps used to fix it. “This is an interesting and pretty big contribution over the decades to the search for artifacts that have barely been opened yet,” said computer scientist Brent Seales at the University of Kentucky. He is not involved in this study. The scientists investigated the Brienne Collection – a postmaster’s chest containing more than 3,000 unsent letters, of which 577 were never opened. Letters sent from all over Europe to the Dutch city of The Hague between 1680 and 1706, the era when Salem witch trials unfold, Newton revealed his law of motion and gravity. King Louis XIV moved the court to Versailles. First, the researchers analyzed four envelopes by scanning high-resolution X-rays to create 3D models of the letter. They then use a new algorithm to identify and separate different layers of folded letters and recognize the written text. In the end, the algorithm virtually unfolds the letters, not only making the handwriting visible, but also records the crease patterns so that the researchers can re-create the step-by-step letter locking process. Scientists use technology to read locked letters dating back centuries. Open up many research directions Scientists have found a way to read the letter without breaking its seal or opening it in any way. Using highly sensitive X-ray scanners and computer algorithms, researchers can read these sealed letters. The new strategy above helps scientists read the text in unopened messages for the first time. For example, an unopened letter is from a man named Jacques Sennacques, dated 31/7/1679 to his cousin Pierre Le Pers – a French businessman in The Hague. Perhaps this letter was intended to obtain a certified copy of the death certificate of a relative, Dainel Le Pers, regarding the inheritance issue. The scientists detailed their findings in the recent Nature Communications journal. This new technique will also work for other collections of unsent mail around the world. For example, “there are so many old origami art pieces that the way they were created has never been recorded,” said study co-author Erik Demaine, a computer scientist at MIT – “The idea of ​​scanning them so they can replicate the way they are folded is really interesting.” The historian Howard Hotson at the University of St Anne in Oxford, UK was not involved in the study, however he stressed that future research on locked letters could shed light on cultural patterns and patterns. global technology exchange “because sophisticated mail locking techniques have been transferred from one country, sector or continent to the respective places over the long period in which it is used”. Scientists are making their technology and open source available for others to use and possibly improve. “We see this as the starting point for many future research directions,” said co-author of the study, algorithm engineer Amanda Ghasaei at Adobe Research in San Francisco.