''Unsolved! The History and Mystery of the World’s Greatest Ciphers from Ancient Egypt to Online Secret Societies'' is a 2017 book by American mathematician and cryptologist Craig P. Bauer. The book explores the history and challenges of various unsolved
ciphers
In cryptography, a cipher (or cypher) is an algorithm for performing encryption or decryption—a series of well-defined steps that can be followed as a procedure. An alternative, less common term is ''encipherment''. To encipher or encode ...
, ranging from ancient scripts to modern codes and puzzles. The book also invites readers to try their hand at cracking the ciphers, offering clues and hints along the way. The book received positive reviews from critics and readers, who praised its engaging style, comprehensive coverage, and intriguing content.
Author
Craig P. Bauer is an American mathematician, cryptologist, and author. He is a professor of mathematics at
York College of Pennsylvania
York College of Pennsylvania is a private college in Spring Garden Township, Pennsylvania. It offers more than 70 baccalaureate majors in professional programs, the sciences, and humanities to 3,500 full-time undergraduate students. It also o ...
, where he teaches courses on
cryptography
Cryptography, or cryptology (from grc, , translit=kryptós "hidden, secret"; and ''graphein'', "to write", or ''-logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of adve ...
,
linear algebra
Linear algebra is the branch of mathematics concerning linear equations such as:
:a_1x_1+\cdots +a_nx_n=b,
linear maps such as:
:(x_1, \ldots, x_n) \mapsto a_1x_1+\cdots +a_nx_n,
and their representations in vector spaces and through matric ...
, and
discrete mathematics
Discrete mathematics is the study of mathematical structures that can be considered "discrete" (in a way analogous to discrete variables, having a bijection with the set of natural numbers) rather than "continuous" (analogously to continu ...
. He is also the editor-in-chief of the international journal ''
Cryptologia
''Cryptologia'' is a journal in cryptography published six times per year since January 1977. Its remit is all aspects of cryptography, with a special emphasis on historical aspects of the subject. The founding editors were Brian J. Winkel, Davi ...
''. He has been a scholar-in-residence at the
National Security Agency’s Center for Cryptologic History.
Contents
The book's first chapter is devoted to
Voynich Manuscript
The Voynich manuscript is an illustrated codex hand-written in an otherwise unknown writing system, referred to as 'Voynichese'. The vellum on which it is written has been carbon-dated to the early 15th century (1404–1438), and stylistic a ...
, which has earned the reputation of being the "book no one can read" due to its unknown language and script, as well as its obscure illustrations. Bauer devotes almost 90 pages to this subject, delving into its historical and cryptographic aspects. He traces the origins and provenance of the manuscript, examines its structure and content, and evaluates various attempts to decode its secrets.
The second chapter, titled "Ancient Ciphers", focuses on the writings and symbols found on
Greek vases
Ancient Greek pottery, due to its relative durability, comprises a large part of the archaeological record of ancient Greece, and since there is so much of it (over 100,000 painted vases are recorded in the Corpus vasorum antiquorum), it has exe ...
, Egyptian sarcophagi, and other objects from ancient times. The author explains that most of these inscriptions are not encrypted messages, but rather require knowledge of the languages and scripts used by the people that produced them. Third chapter features the
Dorabella cryptogram, a cipher composed of semicircles that remains undeciphered for over a century.
Bauer devotes three consecutive chapters (4, 5, and 6) to the analysis of ciphers related to crimes. Chapter 4 examines the case of the
Zodiac Killer
The Zodiac Killer is the pseudonym of an unidentified serial killer who operated in Northern California in the late 1960s. The case has been described as the most famous unsolved murder case in American history. It became a fixture of popular c ...
, a notorious serial murderer who taunted the police and the public with cryptic messages. Bauer offers a comprehensive overview of the Zodiac Killer's history,
modus operandi
A ''modus operandi'' (often shortened to M.O.) is someone's habits of working, particularly in the context of business or criminal investigations, but also more generally. It is a Latin phrase, approximately translated as "mode (or manner) of o ...
, and unsolved ciphers. Chapter 5, titled "More Killer Ciphers", focuses on the
Henry Debosnys
Henry Delactnack Debosnys (c. 1836 – April 27, 1883) was a man who was hanged for murder of his third wife, Elizabeth Wells. His true background remains unknown. Debosnys had two previous wives who died under suspicious circumstances. During hi ...
case. Debosnys was executed in 1883 for killing his wife in
Essex County, New York
Essex County is a county in the U.S. state of New York. As of the 2020 census, the population was 37,381. Its county seat is the hamlet of Elizabethtown. Its name is from the English county of Essex. Essex is one of only 2 counties that are ...
. He left behind encrypted notes that have never been deciphered. The chapter also discusses other criminal cases involving encryption, such as
the Masked Man
The Masked Man is a fictional comic book crime-fighter created by B.C. Boyer and published by Eclipse Comics. His first appearance was in ''Eclipse'' #7, dated November 1982. The Masked Man is the alter ego of private eye Dick Carstairs, w ...
(Germany) and the disappearance of
Susan Powell (USA). In these cases, the suspects used crypto software to conceal their data from the authorities. Bauer explores the challenges and possibilities of cracking these modern ciphers.
In chapter 6, Bauer examines three cases of encrypted messages left by crime victims. The first case is that of
Ricky McCormick, whose body was found in a field in
Missouri
Missouri is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it is bordered by eight states (tied for the most with Tennessee ...
in 1999, along with two notes written in an unknown code. This case has received considerable attention from the U.S. media and the public, but remains unsolved. The second case is that of the
Somerton Man
The Somerton Man was an unidentified man whose body was found on 1 December 1948 on the beach at Somerton Park, a suburb of Adelaide, South Australia. The case is also known after the Persian phrase (Persian: تمام شد), meaning "is over" ...
, a man who was found dead on a beach in
Adelaide
Adelaide ( ) is the list of Australian capital cities, capital city of South Australia, the state's largest city and the list of cities in Australia by population, fifth-most populous city in Australia. "Adelaide" may refer to either Greater A ...
,
Australia, in 1948, with a scrap of paper bearing the words "Tamam Shud" and a cipher hidden in a pocket of his trousers. The third case is that of Paul Rubin, who died of
cyanide poisoning
Cyanide poisoning is poisoning that results from exposure to any of a number of forms of cyanide. Early symptoms include headache, dizziness, fast heart rate, shortness of breath, and vomiting. This phase may then be followed by seizures, s ...
in 1953, leaving behind a note with a series of letters and numbers that have never been deciphered. Bauer conducted extensive research on the Rubin case, uncovering new facts and documents that shed light on his life and death. He also obtained a scan of the original Rubin cryptogram, which he included in his book. Previously, only a partial photograph of the note had been available to the public.
Chapter 7 delves into attempts to use ciphers to prove the possibility of communication with the dead. Bauer describes intriguing challenges for codebreakers that were presented by these experiments. In chapter 8, the book focuses on one of the most enduring challenge ciphers in the history of cryptography, presented by
Joseph O. Mauborgne
Joseph Oswald Mauborgne (February 26, 1881 – June 7, 1971) co-invented the one-time pad with Gilbert Vernam of Bell Labs. In 1914 he published the first recorded solution of the Playfair cipher. Mauborgne became a Major General in the Uni ...
, a prominent U.S. cryptologist, in 1915. The book explains the challenge, provides historical context, and proposes a hypothesis that Mauborgne used a
wheel cypher to encrypt his message.
Chapter 9 of "''Unsolved!''" explores various ciphers that have defied decryption attempts. The author addresses a few classic examples, such as the
D’Agapeyeff challenge,
Feynman
Richard Phillips Feynman (; May 11, 1918 – February 15, 1988) was an American theoretical physicist, known for his work in the path integral formulation of quantum mechanics, the theory of quantum electrodynamics, the physics of the superflu ...
cryptograms, Chinese gold bar ciphers,
Shugborough inscription
The Shugborough Inscription is a sequence of letters – O U O S V A V V, between the letters D M on a lower plane – carved on the 18th-century Shepherd's Monument in the grounds of Shugborough Hall in Staffordshire, England, below a mirror im ...
, and
Kryptos
''Kryptos'' is a sculpture by the United States, American artist Jim Sanborn located on the grounds of the Central Intelligence Agency (CIA) in Langley, Virginia. Since its dedication on November 3, 1990, there has been much speculation about th ...
sculpture. The author argues that final part of Kryptos was encrypted with a matrix-based cipher. The chapter also covers more recent crypto mysteries, such as
Cicada 3301
Cicada 3301 is a nickname given to three sets of puzzles posted under the name "3301" online between 2012 and 2014. The first puzzle started on January 4, 2012, on 4chan and ran for nearly a month. A second round began one year later on January 4, ...
, a mysterious online puzzle with unknown origin and purpose, the
Fenn Treasure
The Fenn Treasure was a cache of gold and jewels that Forrest Fenn, an art dealer and author from Santa Fe, New Mexico, hid in the Rocky Mountains of the United States. It was found approximately a decade later in 2020 in Wyoming by an anonymous ...
, a hidden cache of gold and jewels with a cryptic poem as a clue, and the PCCTS series of encrypted messages from a self-proclaimed
secret society
A secret society is a club or an organization whose activities, events, inner functioning, or membership are concealed. The society may or may not attempt to conceal its existence. The term usually excludes covert groups, such as intelligence ...
. This chapter also describes the
Beale Ciphers
The Beale ciphers are a set of three ciphertexts, one of which allegedly states the location of a buried treasure of gold, silver and jewels estimated to be worth over US$43 million Comprising three ciphertexts, the first (unsolved) text d ...
, which are a set of three cryptograms that allegedly contain the coordinates of a hidden treasure. Bauer argues that the whole story is a hoax and that the ciphers are unsolvable. He contrasts this with another famous case of a pirate treasure linked to a cryptogram: the Levasseur treasure.
Olivier Levasseur
__NOTOC__
Olivier Levasseur (1688, 1689, or 1690 – 7 July 1730), was a French pirate, nicknamed ''La Buse'' ("The Buzzard") or ''La Bouche'' ("The Mouth") in his early days for the speed and ruthlessness with which he always attacked his enem ...
was a pirate who buried a treasure somewhere before his execution. He supposedly left behind a cryptogram written in
Pigpen cipher
The pigpen cipher (alternatively referred to as the masonic cipher, Freemason's cipher, Napoleon cipher, and tic-tac-toe cipher)Barker, p. 40Wrixon, p. 27 is a geometric simple substitution cipher, which exchanges letters for symbols which are f ...
. Bauer explains how the Pigpen cipher works and how it can be cracked with frequency analysis. He suggests that the Levasseur cryptogram might be genuine and that his treasure might still be out there, waiting to be discovered.
Tenth chapter explores the topic of long ciphers encrypted with complex and obscure methods. In addition to the Voynich Manuscript, which was discussed in the first chapter, the book analyzes two other prominent examples of this category:
James Hampton's notebook and the
Codex Rohonci. The book also mentions some modern artistic ciphers, such as the Penitentia Manuscript and the Ricardus Manuscript by
Gordon Rugg
Gordon Rugg (born 1955) is a British academic, head of the Knowledge Modelling Group at Keele University and a visiting senior research fellow at the Open University, known for his work on the Voynich manuscript.Schinner, Andreas. "The Voynich man ...
, and the Book of Woo from the webcomic
Sandra and Woo.
The final chapter of the book explores the possibility of
extraterrestrial communication and the cryptographic challenges involved in deciphering it. It also examines the
RSA Factoring Challenge
The RSA Factoring Challenge was a challenge put forward by RSA Laboratories on March 18, 1991 to encourage research into computational number theory and the practical difficulty of factoring large integers and cracking RSA keys used in cryptograp ...
, a series of mathematical problems posed by the
RSA Laboratories
RSA Security LLC, formerly RSA Security, Inc. and doing business as RSA, is an American computer security, computer and network security company with a focus on encryption and encryption standards. RSA was named after the initials of its co-fo ...
in 1991, and the Time Capsule Crypto Puzzle, a long-term cryptographic experiment devised by
Ron Rivest
Ronald Linn Rivest (; born May 6, 1947) is a cryptographer and an Institute Professor at MIT. He is a member of MIT's Department of Electrical Engineering and Computer Science (EECS) and a member of MIT's Computer Science and Artificial Int ...
in 1999. The author acknowledges that there are many more unsolved cryptograms in history and invites the reader to pursue them further.
The book provides a comprehensive index, extensive notes, and a rich bibliography of references and further reading. It also contains numerous illustrations.
Reception
Andrew Robinson, a writer and historian of cryptography and writing systems, in his review in
''Nature'' praises the book’s scope, logic, speculation and challenges presented to cryptography enthusiasts. The review also notes some drawbacks, such as the varying level of mathematical knowledge required and the omission of some notable examples of decipherment of ancient scripts.
The review by Peter Dabbene in ''Foreword'' magazine praises the book as fascinating and appealing to both newcomers and experienced code breakers. It highlights the book’s wide range of topics and its accessible style. The review suggests that readers that prefer to avoid darker topics such as description of serial murder cases can skip some chapters, but still be entertained by fun tales of spycraft, buried treasure and secret societies. The review concludes by recommending the book to all who enjoy the thrill of the chase.
The review in ''
Cryptologia
''Cryptologia'' is a journal in cryptography published six times per year since January 1977. Its remit is all aspects of cryptography, with a special emphasis on historical aspects of the subject. The founding editors were Brian J. Winkel, Davi ...
'' by Klaus Schmeh, a German computer scientist and crypto history blogger, praises Unsolved! as a major contribution to the crypto history literature and a must-read for codebreakers. Schmeh commends Bauer for his extensive research, his captivating writing style, and his coverage of both classic and modern cipher mysteries. Schmeh also appreciates Bauer’s skepticism and focus on the cryptographic properties of the unsolved cryptograms, rather than the speculative theories that surround them. Schmeh notes a few errors and omissions in Unsolved!, such as the nature of the error in K3 of the Kryptos sculpture, and the lack of discussion of modern cryptography, but hopes that Bauer will address them in future publications.
Solved ciphers
Some of the cryptograms described in the book were deciphered after its publication. "The Masked Man" revealed his passwords in 2016, which allowed his data to be decrypted. In 2020, the 340-character Zodiac cipher was solved.
The "Somerton Man" was identified based on genetic genealogy.
The
Fenn treasure
The Fenn Treasure was a cache of gold and jewels that Forrest Fenn, an art dealer and author from Santa Fe, New Mexico, hid in the Rocky Mountains of the United States. It was found approximately a decade later in 2020 in Wyoming by an anonymous ...
was found. The English translation of the Book of Woo was published by its creator.
References
{{reflist
Cryptography books
2017 non-fiction books