Friedrich Kasiski
Encyclopedia
Major
Friedrich Wilhelm Kasiski (29 November 1805 – 22 May 1881) was a Prussia
n infantry
officer
, cryptographer and archeologist. Kasiski was born in Schlochau, West Prussia
(now Człuchów, Poland
).
's 33rd Infantry Regiment
on 20 March 1823 at the age of 17. In May 1824, he was promoted to the rank
of Master Sergeant
, and eight months later was commissioned as a Second Lieutenant
in February 1825. It took fourteen years to earn his next promotion
when, in May 1839, he advanced to the rank of First Lieutenant
. His next advancement was quicker, promoted to Captain in November 1842. Kasiski finally retired from active service with the rank of Major on 17 February 1852.
Between 1860 and 1868 he was the commander of a National Guard battalion
.
, Die Geheimschriften und die Dechiffrierkunst (German
, "Secret writing and the Art of Deciphering"). This was the first published account of a procedure for attacking
polyalphabetic substitution ciphers, especially the Vigenère cipher
(although it is possible Charles Babbage
was already aware of a similar method but had kept it secret). The method relied on the analysis of gaps between repeated fragments in the ciphertext
; such analysis can give hints as to the length of the key
used. This technique is known as Kasiski examination
.
The significance of Kasiski's cryptanalytic work was not widely realised at the time, and he turned his mind to archaeology
instead. The later years of his life were spent at Neustettin (Szczecinek
); the 11th edition of Encyclopædia Britannica
cited a scholarly article by Kasiski in its entry on the town. Historian
David Kahn notes, "Kasiski died on May 22, 1881, almost certainly without realizing that he had wrought a revolution in cryptology" (The Codebreakers
).
Major
Major is a rank of commissioned officer, with corresponding ranks existing in almost every military in the world.When used unhyphenated, in conjunction with no other indicator of rank, the term refers to the rank just senior to that of an Army captain and just below the rank of lieutenant colonel. ...
Friedrich Wilhelm Kasiski (29 November 1805 – 22 May 1881) was a Prussia
Prussia
Prussia was a German kingdom and historic state originating out of the Duchy of Prussia and the Margraviate of Brandenburg. For centuries, the House of Hohenzollern ruled Prussia, successfully expanding its size by way of an unusually well-organized and effective army. Prussia shaped the history...
n infantry
Infantry
Infantrymen are soldiers who are specifically trained for the role of fighting on foot to engage the enemy face to face and have historically borne the brunt of the casualties of combat in wars. As the oldest branch of combat arms, they are the backbone of armies...
officer
Officer (armed forces)
An officer is a member of an armed force or uniformed service who holds a position of authority. Commissioned officers derive authority directly from a sovereign power and, as such, hold a commission charging them with the duties and responsibilities of a specific office or position...
, cryptographer and archeologist. Kasiski was born in Schlochau, West Prussia
West Prussia
West Prussia was a province of the Kingdom of Prussia from 1773–1824 and 1878–1919/20 which was created out of the earlier Polish province of Royal Prussia...
(now Człuchów, Poland
Poland
Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...
).
Military service
Kasiski enlisted in East PrussiaEast Prussia
East Prussia is the main part of the region of Prussia along the southeastern Baltic Coast from the 13th century to the end of World War II in May 1945. From 1772–1829 and 1878–1945, the Province of East Prussia was part of the German state of Prussia. The capital city was Königsberg.East Prussia...
's 33rd Infantry Regiment
Regiment
A regiment is a major tactical military unit, composed of variable numbers of batteries, squadrons or battalions, commanded by a colonel or lieutenant colonel...
on 20 March 1823 at the age of 17. In May 1824, he was promoted to the rank
Military rank
Military rank is a system of hierarchical relationships in armed forces or civil institutions organized along military lines. Usually, uniforms denote the bearer's rank by particular insignia affixed to the uniforms...
of Master Sergeant
Master Sergeant
A master sergeant is the military rank for a senior non-commissioned officer in some armed forces.-Israel Defense Forces:Rav samal rishoninsignia IDF...
, and eight months later was commissioned as a Second Lieutenant
Second Lieutenant
Second lieutenant is a junior commissioned officer military rank in many armed forces.- United Kingdom and Commonwealth :The rank second lieutenant was introduced throughout the British Army in 1871 to replace the rank of ensign , although it had long been used in the Royal Artillery, Royal...
in February 1825. It took fourteen years to earn his next promotion
Promotion (rank)
A promotion is the advancement of an employee's rank or position in an organizational hierarchy system. Promotion may be an employee's reward for good performance i.e. positive appraisal...
when, in May 1839, he advanced to the rank of First Lieutenant
First Lieutenant
First lieutenant is a military rank and, in some forces, an appointment.The rank of lieutenant has different meanings in different military formations , but the majority of cases it is common for it to be sub-divided into a senior and junior rank...
. His next advancement was quicker, promoted to Captain in November 1842. Kasiski finally retired from active service with the rank of Major on 17 February 1852.
Between 1860 and 1868 he was the commander of a National Guard battalion
Battalion
A battalion is a military unit of around 300–1,200 soldiers usually consisting of between two and seven companies and typically commanded by either a Lieutenant Colonel or a Colonel...
.
Cryptography
In 1863, Kasiski published a 95-page book on cryptographyCryptography
Cryptography is the practice and study of techniques for secure communication in the presence of third parties...
, Die Geheimschriften und die Dechiffrierkunst (German
German language
German is a West Germanic language, related to and classified alongside English and Dutch. With an estimated 90 – 98 million native speakers, German is one of the world's major languages and is the most widely-spoken first language in the European Union....
, "Secret writing and the Art of Deciphering"). This was the first published account of a procedure for attacking
Cryptanalysis
Cryptanalysis is the study of methods for obtaining the meaning of encrypted information, without access to the secret information that is normally required to do so. Typically, this involves knowing how the system works and finding a secret key...
polyalphabetic substitution ciphers, especially the Vigenère cipher
Vigenère cipher
The Vigenère cipher is a method of encrypting alphabetic text by using a series of different Caesar ciphers based on the letters of a keyword. It is a simple form of polyalphabetic substitution....
(although it is possible Charles Babbage
Charles Babbage
Charles Babbage, FRS was an English mathematician, philosopher, inventor and mechanical engineer who originated the concept of a programmable computer...
was already aware of a similar method but had kept it secret). The method relied on the analysis of gaps between repeated fragments in the ciphertext
Ciphertext
In cryptography, ciphertext is the result of encryption performed on plaintext using an algorithm, called a cipher. Ciphertext is also known as encrypted or encoded information because it contains a form of the original plaintext that is unreadable by a human or computer without the proper cipher...
; such analysis can give hints as to the length of the key
Key (cryptography)
In cryptography, a key is a piece of information that determines the functional output of a cryptographic algorithm or cipher. Without a key, the algorithm would produce no useful result. In encryption, a key specifies the particular transformation of plaintext into ciphertext, or vice versa...
used. This technique is known as Kasiski examination
Kasiski examination
In cryptanalysis, Kasiski examination is a method of attacking polyalphabetic substitution ciphers, such as the Vigenère cipher...
.
The significance of Kasiski's cryptanalytic work was not widely realised at the time, and he turned his mind to archaeology
Archaeology
Archaeology, or archeology , is the study of human society, primarily through the recovery and analysis of the material culture and environmental data that they have left behind, which includes artifacts, architecture, biofacts and cultural landscapes...
instead. The later years of his life were spent at Neustettin (Szczecinek
Szczecinek
Szczecinek [] is a city in Middle Pomerania, northwestern Poland with some 39,777 inhabitants . Previously in Koszalin Voivodeship , it has been the capital of Szczecinek County in the West Pomeranian Voivodeship since 1999...
); the 11th edition of Encyclopædia Britannica
Encyclopædia Britannica Eleventh Edition
The Encyclopædia Britannica Eleventh Edition is a 29-volume reference work, an edition of the Encyclopædia Britannica. It was developed during the encyclopaedia's transition from a British to an American publication. Some of its articles were written by the best-known scholars of the time...
cited a scholarly article by Kasiski in its entry on the town. Historian
Historian
A historian is a person who studies and writes about the past and is regarded as an authority on it. Historians are concerned with the continuous, methodical narrative and research of past events as relating to the human race; as well as the study of all history in time. If the individual is...
David Kahn notes, "Kasiski died on May 22, 1881, almost certainly without realizing that he had wrought a revolution in cryptology" (The Codebreakers
The Codebreakers
The Codebreakers – The Story of Secret Writing is a book by David Kahn, published in 1967 comprehensively chronicling the history of cryptography from ancient Egypt to the time of its writing...
).
See also
- List of cryptographers
- Topics in cryptography