Enlarge / “Paul Ramify loamy event false new event” was one of the lines written on two sheets of paper found in a hidden pocket. (credit: Sara Rivers Cofield)

In December 2013, a curator and archaeologist purchased an antique silk dress with an unusual feature: a hidden pocket that held two sheets of paper with mysterious coded text written on them. People have been trying to crack the code ever since, and someone finally succeeded: University of Manitoba data analyst Wayne Chan. He discovered that the text is actually coded telegraph messages describing the weather used by the US Army and (later) the weather bureau. Chan outlined all the details of his decryption in a paper published in the journal Cryptologia.

“When I first thought I cracked it, I did feel really excited,” Chan told the New York Times. “It is probably one of the most complex telegraphic codes that I’ve ever seen.”

Sara Rivers-Cofield purchased the bronze-colored silk bustle dress with striped rust velvet accents for $100 at an antique shop in Maine, noting on her blog that it was in a style that was fashionable in the mid-1880s among middle-class or well-off women. There wasn't any fitted boning in the bodice, so the dress was meant to be worn with a corset. It had a draped skirt and bustle with metal buttons decorated with an "Ophelia motif." While the dress had been machine-stitched, the original buttons had been sewn by hand. A tag with the name "Bennett" was sewn into the bodice.

Enlarge / Sample ciphertext (F38) found in the archives of the Bibliothèque Nationale de France, now attributed to Mary, Queen of Scots. (credit: Bibliothèque nationale de France)

An international team of code-breakers has successfully cracked the cipher of over 50 mysterious letters unearthed in French archives. The team discovered that the letters had been written by Mary, Queen of Scots, to trusted allies during her imprisonment in England by Queen Elizabeth I (her cousin)—and most were previously unknown to historians. The team described in a new paper published in the journal Cryptologia how they broke Mary's cipher, then decoded and translated several of the letters. The publication coincides with the anniversary of Mary's execution on February 8, 1587.

"This is a truly exciting discovery," said co-author George Lasry , a computer scientist and cryptographer in Israel. "Mary, Queen of Scots, has left an extensive corpus of letters held in various archives. There was prior evidence, however, that other letters from Mary Stuart were missing from those collections, such as those referenced in other sources but not found elsewhere. The letters we have deciphered are most likely part of this lost secret correspondence.” Lasry is part of the multi-disciplinary DECRYPT Project devoted to mapping, digitizing, transcribing, and deciphering historical ciphers.

Mary sought to protect her most private letters from being intercepted and read by hostile parties. For instance, she engaged in what's known as " letter-locking ," a common practice at the time to protect private letters from prying eyes. As we've reported previously , Jana Dambrogio, a conservator at MIT Libraries, coined the term "letter-locking" after discovering such letters while a fellow at the Vatican Secret Archives in 2000.

Enlarge / Researchers have finally cracked the secret code of this 1547 letter from Holy Roman Emperor Charles V to his ambassador. (credit: Bibliotheque Stanislas de Nancy)

In 1547, Holy Roman Emperor Charles V penned a letter to his ambassador, Jean de Saint-Mauris, part of which was written in the ruler's secret code. Nearly five centuries later, researchers have finally cracked that code , revealing Charles V's fear of a secret assassination plot and continued tensions with France, despite having signed a peace treaty with the French king a few years earlier.

The future Holy Roman Emperor was born in 1500 to Philip of Hapsburg and Joanna of Trastamara—daughter of Ferdinand II of Aragon and Isabella I of Castile in Spain. She was nicknamed "Joanna the Mad" because of her rumored mental illness and actually gave birth to Charles in a bathroom in the wee hours because she insisted on attending a ball despite clearly having labor pains. Generations of inbreeding conferred on Charles an enlarged jaw (mandibular prognathism), a condition that later became known as "Hapsburg jaw," since it became even worse in subsequent generations. Charles also suffered from epilepsy and gout; the latter became so severe late in life that he had to be carried around in a sedan chair.

Charles V began inheriting various family titles at a young age, and his dominion eventually encompassed the Holy Roman Empire—which extended from Germany to northern Italy in the early 16th century and included Austrian hereditary lands, the Burgundian states, and the Kingdom of Spain. During his reign, he continued the Spanish colonization of the Americas and embarked on a short-lived German colonization effort, earning the label "the empire on which the sun never sets." As his health deteriorated, Charles V abdicated as emperor in favor of his brother Ferdinand in 1556, although it was not legally recognized until February 1558. He retired to the Monastery of Yuste in 1557 and died the following September.