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M-94
The M-94 was a piece of cryptographic equipment used by the United States Army, consisting of several lettered discs arranged as a cylinder. It was also employed by the US Navy, under the name CSP 488. The device was conceived by Colonel Parker Hitt and then developed by Major Joseph Mauborgne in 1917; based on a system invented by Thomas Jefferson and Etienne Bazeries. Officially adopted in 1922, it remained in use until circa 1942, when it was replaced by more complex and secure electromechanical rotor machines, particularly the M-209. Principle The device consisted of 25 aluminium discs attached to a four-and-a-half inch long rod, each disc containing the 26 letters of the Roman alphabet in scrambled order around its circumference (with the exception of the 17th disc, which began with the letters "ARMY OF THE US"). Each wheel had a different arrangement of the alphabet, and was stamped with an identifying number and letter; wheels were identified according to the letter fol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
M-138-A Strip Cipher - National Cryptologic Museum - DSC07930
The M-94 was a piece of cryptographic equipment used by the United States Army, consisting of several lettered discs arranged as a cylinder. It was also employed by the US Navy, under the name CSP 488. The device was conceived by Colonel Parker Hitt and then developed by Major Joseph Mauborgne in 1917; based on a system invented by Thomas Jefferson and Etienne Bazeries. Officially adopted in 1922, it remained in use until circa 1942, when it was replaced by more complex and secure electromechanical rotor machines, particularly the M-209. Principle The device consisted of 25 aluminium discs attached to a four-and-a-half inch long rod, each disc containing the 26 letters of the Roman alphabet in scrambled order around its circumference (with the exception of the 17th disc, which began with the letters "ARMY OF THE US"). Each wheel had a different arrangement of the alphabet, and was stamped with an identifying number and letter; wheels were identified according to the letter fol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jefferson Disk
The Jefferson disk, also called the Bazeries Cylinder or wheel cypher as named by Thomas Jefferson, is a cipher system using a set of wheels or disks, each with the 26 letters of the alphabet arranged around their edge. The order of the letters is different for each disk and is usually ordered randomly. Each disk is marked with a unique number and a hole in the center of the disks allows them to be stacked on an axle. The disks are removable and can be mounted on the axle in any order desired. The order of the disks is the cipher key, and both sender and receiver must arrange the disks in the same predefined order. Jefferson's device had 36 disks.Kahn, p. 194 Once the disks have been placed on the axle in the agreed order, the sender rotates each disk up and down until a desired message is spelled out in one row. Then, the sender can copy down any row of text on the disks other than the one that contains the plaintext message. The recipient has to arrange the disks in the agreed- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Encryption Devices
In cryptography, encryption is the process of encoding information. This process converts the original representation of the information, known as plaintext, into an alternative form known as ciphertext. Ideally, only authorized parties can decipher a ciphertext back to plaintext and access the original information. Encryption does not itself prevent interference but denies the intelligible content to a would-be interceptor. For technical reasons, an encryption scheme usually uses a pseudo-random encryption key generated by an algorithm. It is possible to decrypt the message without possessing the key but, for a well-designed encryption scheme, considerable computational resources and skills are required. An authorized recipient can easily decrypt the message with the key provided by the originator to recipients but not to unauthorized users. Historically, various forms of encryption have been used to aid in cryptography. Early encryption techniques were often used in military ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wheel Cipher
The Jefferson disk, also called the Bazeries Cylinder or wheel cypher as named by Thomas Jefferson, is a cipher system using a set of wheels or disks, each with the 26 letters of the alphabet arranged around their edge. The order of the letters is different for each disk and is usually ordered randomly. Each disk is marked with a unique number and a hole in the center of the disks allows them to be stacked on an axle. The disks are removable and can be mounted on the axle in any order desired. The order of the disks is the cipher key, and both sender and receiver must arrange the disks in the same predefined order. Jefferson's device had 36 disks.Kahn, p. 194 Once the disks have been placed on the axle in the agreed order, the sender rotates each disk up and down until a desired message is spelled out in one row. Then, the sender can copy down any row of text on the disks other than the one that contains the plaintext message. The recipient has to arrange the disks in the agreed- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
M-209
In cryptography, the M-209, designated CSP-1500 by the United States Navy (C-38 by the manufacturer) is a portable, mechanical cipher machine used by the US military primarily in World War II, though it remained in active use through the Korean War. The M-209 was designed by Swedish cryptographer Boris Hagelin in response to a request for such a portable cipher machine, and was an improvement of an earlier machine, the C-36. The M-209 is about the size of a lunchbox, in its final form measuring and weighing (plus for the case). It represented a brilliant achievement for pre-electronic technology. It was a rotor machine similar to a telecipher machine, such as the Lorenz cipher and the Geheimfernschreiber. Basic operation Basic operation of the M-209 is relatively straightforward. Six adjustable ''key wheels'' on top of the box each display a letter of the alphabet. These six wheels comprise the external key for the machine, providing an initial state, similar to an initial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plaintext
In cryptography, plaintext usually means unencrypted information pending input into cryptographic algorithms, usually encryption algorithms. This usually refers to data that is transmitted or stored unencrypted. Overview With the advent of computing, the term ''plaintext'' expanded beyond human-readable documents to mean any data, including binary files, in a form that can be viewed or used without requiring a key or other decryption device. Information—a message, document, file, etc.—if to be communicated or stored in an unencrypted form is referred to as plaintext. Plaintext is used as input to an encryption algorithm; the output is usually termed ciphertext, particularly when the algorithm is a cipher. Codetext is less often used, and almost always only when the algorithm involved is actually a code. Some systems use multiple layers of encryption, with the output of one encryption algorithm becoming "plaintext" input for the next. Secure handling Insecure handling of p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Classical Ciphers
Classical may refer to: European antiquity *Classical antiquity, a period of history from roughly the 7th or 8th century B.C.E. to the 5th century C.E. centered on the Mediterranean Sea *Classical architecture, architecture derived from Greek and Roman architecture of classical antiquity *Classical mythology, the body of myths from the ancient Greeks and Romans *Classical tradition, the reception of classical Greco-Roman antiquity by later cultures *Classics, study of the language and culture of classical antiquity, particularly its literature *Classicism, a high regard for classical antiquity in the arts Music and arts *Classical ballet, the most formal of the ballet styles *Classical music, a variety of Western musical styles from the 9th century to the present *Classical guitar, a common type of acoustic guitar *Classical Hollywood cinema, a visual and sound style in the American film industry between 1927 and 1963 * Classical Indian dance, various codified art forms whose theo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SIGABA
In the history of cryptography, the ECM Mark II was a cipher machine used by the United States for message encryption from World War II until the 1950s. The machine was also known as the SIGABA or Converter M-134 by the Army, or CSP-888/889 by the Navy, and a modified Navy version was termed the CSP-2900. Like many machines of the era it used an electromechanical system of rotors to encipher messages, but with a number of security improvements over previous designs. No successful cryptanalysis of the machine during its service lifetime is publicly known. History It was clear to US cryptographers well before World War II that the single-stepping mechanical motion of rotor machines (e.g. the Hebern machine) could be exploited by attackers. In the case of the famous Enigma machine, these attacks were supposed to be upset by moving the rotors to random locations at the start of each new message. This, however, proved not to be secure enough, and German Enigma messages were freque ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BATCO
BATCO, short for Battle Code, is a hand-held, paper-based encryption system used at a low, front line (platoon, troop and section) level in the British Army. It was introduced along with the Clansman combat net radio in the early 1980s and was largely obsolete by 2010 due to the wide deployment of the secure Bowman radios. BATCO consists of a code, contained on a set of vocabulary cards, and cipher sheets for superencryption of the numeric code words. The cipher sheets, which are typically changed daily, also include an authentication table and a radio call sign protection system. BATCO is similar to older Slidex system. The use of BATCO is still taught to Royal Signals Communication Systems Operators as a back-up should secure equipment fail or be unavailable. It is also taught to Army Cadets and Combined Cadets as part of the Signal Classification qualification. Code Messages in BATCO are first encoded into numbers using one of several vocabulary cards. The BATCO cipher is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DRYAD (Cryptography)
A dryad (; el, Δρυάδες, ''sing''.: ) is a tree nymph or tree spirit in Greek mythology. ''Drys'' (δρῦς) signifies "oak" in Greek, and dryads were originally considered the nymphs of oak trees specifically, but the term has evolved towards tree nymphs in general,Graves, ch. 86.2; p. 289 or human-tree hybrids in fantasy. Often their life force was connected to the tree in which they resided and they were usually found in sacred groves of the gods. They were considered to be very shy creatures except around the goddess Artemis, who was known to be a friend to most nymphs. Types Daphnaie These were nymphs of the laurel trees. Epimelides The Maliades, Meliades or Epimelides were nymphs of apple and other fruit trees and the protectors of sheep. The Greek word ''melas'', from which their name derives, means both apple and sheep. Hesperides, the guardians of the golden apples were regarded as this type of dryad. Hamadryad Dryads, like all nymphs, were supernaturally ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing military alliances: the Allies and the Axis powers. World War II was a total war that directly involved more than 100 million personnel from more than 30 countries. The major participants in the war threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. Aircraft played a major role in the conflict, enabling the strategic bombing of population centres and deploying the only two nuclear weapons ever used in war. World War II was by far the deadliest conflict in human history; it resulted in 70 to 85 million fatalities, mostly among civilians. Tens of millions died due to genocides (including the Holocaust), starvation, ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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