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Topic: Cipher Disk

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Chapter 2: The 2nd Cryptographic Shakespeare The Jefferson disk cipher cylinder can be read either backward or forward, depending upon whether a letter has been subtracted or added from its original position in the alphabet. It was composed of twenty-six brass disks about 3/8" thick. The cipher letters could then be selected at random from any one of the twenty-five remaining rows and later transmitted by radio. home.att.net /~mleary/pennl2.htm

studysheet Monalphabetic substitution Polyalphabetic subsitution Alberti's disk Autokey cipher Vigenere cipher Jefferson wheel Book cipher Wadsworth disk Wheatstone disk Pliny Chase's system Felix Delastelle's system Playfair cipher UBCHI ADFGVX RSA cipher RSA electronic signature Diffie-Hellman key exchange system Massey-Omura cipher Know who the following people were and what each invented relative to cryptography. Trithemius: the tableau Belaso: the key phrase Porta: digraphic ciphers; the mixed alphabet tableau Cardano: the autokey; the grille Vigenere: a working autokey system Rossignol: the two-part nomenclator Be familiar with the material on the Enigma machine. Know how each of the following cipher systems work. www.lclark.edu /~krussel/studysheet

studysheet Monalphabetic substitution Polyalphabetic subsitution Alberti's disk Autokey cipher Vigenere cipher Jefferson wheel Book cipher Wadsworth disk Wheatstone disk Pliny Chase's system Felix Delastelle's system Playfair cipher UBCHI ADFGVX RSA cipher RSA electronic signature Diffie-Hellman key exchange system Massey-Omura cipher Know who the following people were and what each invented relative to cryptography. Trithemius: the tableau Belaso: the key phrase Porta: digraphic ciphers; the mixed alphabet tableau Cardano: the autokey; the grille Vigenere: a working autokey system Rossignol: the two-part nomenclator Be familiar with the material on the Enigma machine. Know how each of the following cipher systems work. www.lclark.edu /~krussel/studysheet   (128 words)

Disk Jefferson disk Jefferson Disk Cipher During Thomas Jefferson invented a cipher system using 26 wheels, each with the let... Disk filter A disk filter is a type of water filter similar to a water passes through the small grooves in between and t... Disk (mathematics) In plane A representative disk is three-dimensional volume element of a volume, of π∫r w units... www.brainyencyclopedia.com /topics/disk.html   (128 words)

Mini Tutorial - Internet for You, Part 7: Internet Security A cookie is a message, text strings, sent from a Web server to the user's computer that is stored on the user's hard disk. A Web site can only read data from its own cookie file; it cannot access or view any data on the user's hard disk. Cookies are not harmful, they are just short text strings, and they can often improve browsing by allowing a server to recall any customized information the user has set. www.rsna.org /tech/internet/internet7-1.html   (128 words)

Linux hard disk encryption settings - clemens.endorphin.org The logical index is usually the absolute position on disk measured with the block size of the cipher algorithm. To make a cipher block tied to a location on disk (to make it unmovable), a logical index is included in the computation. Thus, if we would run the whole hard disk encryption in CBC mode, one would have to re-encrypt the whole hard disk, if the first computation step changed, this is, when the first plain text block changed. clemens.endorphin.org /LinuxHDEncSettings   (2633 words)

Jefferson disk Jefferson's disk cipher was 100 years ahead of its time During 1795, Thomas Jefferson invented a cipher system using 26 wheels, each with the letters of the alphabet arranged randomly around them. However, the U.S. Army never knew of Jefferson's invention; it reinvented it. www.worldhistory.com /wiki/J/Jefferson-disk.htm   (2633 words)

M-94 - Wikipedia, the free encyclopedia The Jefferson Wheel Cipher  ( http://www.murky.org/cryptography/classical/jefferson.shtml) as discussed on Wheel ciphers could be broken, even in WWII, if enough ciphertext was intercepted. DRYAD cipher currently in use by the U.S. military is not much more sophisticated. en.wikipedia.org /wiki/M-94   (2633 words)

Secret Code Breaker: The Cipher that Caesar Used Later, any cipher that used this "displacement" concept for the creation of a cipher alphabet, was referred to as a Caesar cipher. A disk or wheel has the alphabet printed on it and then a movable smaller disk or wheel with the same alphabet printed on it is mounted forming an inner wheel. Of all the substitution type ciphers, this Caesar cipher is the simplest to solve, since there are only 25 possible combinations. codebrkr.infopages.net /history2.htm   (283 words)

Photos from Laurel, Maryland -- Declan McCullagh photographs confederate-cipher-disk / Confederate cipher disk, basically a weak Caesar cipher that does not scramble the alphabet 18th-century-cipher-device / 18th century device, perhaps the oldest cipher device with possible ties to Thomas Jefferson japanese-enigma-cipher-machine / Japanese Enigma-type rotor cipher machine used in World II and typically made in Germany www.mccullagh.org /location/laurelmaryland.html   (381 words)

Case Study When the CSS Stream Cipher is being used in either "Decryption of the Disk Key" or "Decryption of the Title Key" modes, the input data is mangled in a further step using a mangling function (Figure 3: CSS Mangling Function) before being exclusive ORed with the output of the Stream Cipher. Once the CSS Stream Cipher had been uncovered and it was realised that 40 bit keys were in use (due to export restrictions in the US), a "Brute Force" Attack on the Disk Key Kd was possible. In this section I’ll outline the attacks that have been used on the CSS Stream Cipher thus far, and attempt to build an Attack Tree, which could be used to cryptanalyse and evaluate other such proprietary systems, and hence be added to a cryptanalyst’s tool. www-2.cs.cmu.edu /~dst/DeCSS/Cherry   (381 words)

Cryptology ePrint Archive We suggest that EMD provides an attractive solution to the disk-sector encryption problem, where one wants to encipher the contents of an $nm$-bit disk sector in a way that depends on the sector index and is secure against chosen-plaintext/chosen-ciphertext attack. Encryption and decryption are identical except that encryption uses the forward direction of the underlying block cipher and decryption uses the backwards direction. We describe a block-cipher mode of operation, EMD, that builds a strong pseudorandom permutation (PRP) on $nm$ bits ($m\ge2$) out of a strong PRP on $n$ bits (i.e., a block cipher). eprint.iacr.org /2002/148   (174 words)

Polyalphabetic cipher - Wikipedia, the free encyclopedia Alberti also invented a decoder device, his encryption disk, which implemented a cipher equivalent to the one published later by Johannes Trithemius. The Vigenère cipher is probably the best-known example of a polyalphabetic cipher, though it is a simplified special case. Alberti used a Caesar cipher to encrypt a message, but whenever he wanted to he would switch to a different alphabet, indicating that he had done so by capitalizing the first letter encrypted with the new alphabet. en.wikipedia.org /wiki/Polyalphabetic_cipher   (488 words)

Polyalphabetic cipher Alberti also invented a decoder device, his encryption disk, which implemented a cipher equivalent to the one published later by Johannes Trithemius. The Vigenère cipher is probably the best-known example of a polyalphabetic cipher, though it is a simplified special case. Alberti used a Caesar cipher to encrypt a message, but whenever he wanted to he would switch to a different alphabet, indicating that he had done so by capitalizing the first letter encrypted with the new alphabet. stevehome.dynup.net /en/Polyalphabetic_cipher.htm   (471 words)

Leone Battista Alberti - Open Encyclopedia Alberti was an accomplished cryptographer by the standard of his day, and invented both polyalphabetic ciphers and machine-assisted encryption using his cipher disk. The polyalphabetic cipher was, at least in principle, for it was not properly used for several hundred years, the most signifcant advance in cryptography since before Julius Caesar's time. Cryptography historian David Kahn titles him the "Father of Western Cryptography", pointing to three significant advances in the field which can be attributed to Alberti: "the earliest Western exposition of cryptanalysis, the invention of polyalphabetic substitution, and the invention of enciphered code" (The Codebreakers, 1967). open-encyclopedia.com /Leone_Battista_Alberti   (600 words)

ciphergoth.org: Mercy: A fast large block cipher for disk sector encryption We discuss the special requirements imposed on the underlying cipher of systems which encrypt each sector of a disk partition independently, and demonstrate a certificational weakness in some existing block ciphers including Bellare and Rogaway's 1999 proposal, proposing a new quantitative measure of avalanche. Cryptanalysis of the Mercy block cipher, Scott Fluhrer, FSE 2001. To address these needs, we present Mercy, a new block cipher accepting large (4096-bit) blocks, which uses a key-dependent state machine to build a bijective F function for a Feistel cipher. www.ciphergoth.org /crypto/mercy   (413 words)

Electronic Wheel Cipher is Added to Monticello Site As long as the recipient had exact copies of each disk in the exact same order as the sender, the original message would appear when one row of the cipher was set to the encoded letters. Three computer science students at the University of Virginia have created an electronic version of Thomas Jefferson's Wheel Cipher that allows visitors to Monticello's Web site to encode and decode short messages and send them via e-mail. The electronic Wheel Cipher and instructions on how to use it are accessible at www.monticello.org/jefferson/wheelcipher. www.cs.virginia.edu /csnews/show.php?artID=252   (413 words)

Polyalphabetic Substitution The plaintext alphabet on his cipher disk was in order, and included the digits 1 through 4 for forming codewords from a small vocabulary. Cipher disks are harder to make than slides, but they do look prettier. The idea of using substitution ciphers that change during the course of a message was a very important step forwards in cryptography. www.quadibloc.com /crypto/pp010103.htm   (5179 words)

Lanaki Lesson 4 The Mexican Cipher device is a Homophonic consisting of five concentric disks, the outer disk bearing 26 letters and the other four bearing sequences 01-26, 27-52, 53-78, 79-00. If the cipher text is of 5-figure code type, then such repetitions as appear should generally be in whole groups of five digits, and they should be visible in the text just as the message stands, unless the code message has been superenciphered. If the cryptogram is a cipher, then repetitions should extend beyond the 5-digit groupings; if they conform to any definite at all they should for the most part contain even numbers of digits since each letter is probably represented by a pair (dinome) of digits. www.fortunecity.com /skyscraper/coding/379/lesson4.htm   (1459 words)

Cryptology Although field cipher systems such as the U.S. Signal Corps cipher disk lacked sophistication some complicated cipher systems were used for high-level communications by the end of the war. By 1860 large codes were in common use for diplomatic communications and cipher systems had become a rarity for this application however cipher systems prevailed for military communications (except for high-command communications because of the difficulty of protecting codebooks from capture or compromise). While the encryption of any particular plaintext with a block cipher will result in the same ciphertext when the same key is used; with a stream cipher, the transformation of the smaller plaintext units will vary, depending on when they are encountered during the encryption process. www.ridex.co.uk /cryptology   (1459 words)

Polyalphabetic Substitution The plaintext alphabet on his cipher disk was in order, and included the digits 1 through 4 for forming codewords from a small vocabulary. The idea of using substitution ciphers that change during the course of a message was a very important step forwards in cryptography. However, although imperfect, it is less so than the Gronsfeld cipher, and so the system might be of some use (although just converting to digits with a straddling checkerboard achieves the same goal, of simplifying applying a key, without any imperfections, and considerably more simply). www.quadibloc.com /crypto/pp010303.htm   (6453 words)

Linux Encryption HOWTO: Encrypting Disks Without this option enabled, you have to make sure it stays at the exact same place on the disk in order to use it, because the (absolute, as opposed to relative) block numbers the file occupies on disk affect the crypto cipher, see the question on copying files in the FAQ section. This is a short summary of disk encryption related kernel config options. CFS is the first free UNIX disk encryption program hacked by well-known Matt Blaze. encryptionhowto.sourceforge.net /Encryption-HOWTO-4.html   (3442 words)

math lessons - Tabula recta Trithemius used the tabula recta to define a polyalphabetic cipher which was equivalent to Leon Battista Alberti's cipher disk. The tabula recta is often referred to in discussing pre-computer ciphers, including the Vigenère cipher and Blaise de Vigenère's less well-known (but much stronger) autokey cipher. All polyalphabetic ciphers based on Caesar ciphers can be described in terms of the tabula recta. www.mathdaily.com /lessons/Tabula_recta   (109 words)

CME's Cryptography Timeline Colonel Decius Wadsworth produced a geared cipher disk with a different number of letters in the plain and cipher alphabets -- resulting in a progressive cipher in which alphabets are used irregularly, depending on the plaintext used. He invented a steganographic cipher in which each letter was represented as a word taken from a succession of columns. This cipher uses a keyed array of letters to make a digraphic cipher which is easy to use in the field. world.std.com /~cme/html/timeline.html   (3709 words)

Lou Kruh's Collection This is a cipher disk with 6 wheels. Swiss NEMA.U.S.Army 30 Strip Cipher Device,M-138-A, a folding aluminum board with simulated strips and original carry case.Also a U.S. Army M-325, a three rotor device, invented by William F. Friedman based on the German Enigma was used by the U.S. State Department 1942-1924, the only known copy in private hands. Cipher machines/devices include: U.S. Army M-94, whose origin can be traced back to Thomas Jefferson, www.loukruh.com   (3709 words)

Cryptographic Protection of Computer Information Symmetrical ciphers are best suited for cases when computer information is just stored on the hard disk, floppies or other mediums. Symmetric ciphers is DES (Data Encryption Standard), created in due time by IBM and is used in the US as a federal standard. This cipher is much slower than the symmetric cipher and so is usually used to send the key to a symmetric cipher. www.crime-research.org /articles/Akhtyrskaya0604   (3709 words)

Arcanum Computing Cipher is a crypt-quotes type word puzzle game, such as you might find in the newspaper. To use any of the downloadable trial versions just download the file(s), unzip everything into a single directory on your hard disk and run the game file (the one with a file name ending in ".exe"). Shih Dao v3.7 is a solitaire game that challenges you to earn points by placing tiles of the same color or pattern next to each other. www.flightsim.com /arcanum/arcanum.htm   (796 words)

CME's Cryptography Timeline Colonel Decius Wadsworth produced a geared cipher disk with a different number of letters in the plain and cipher alphabets -- resulting in a progressive cipher in which alphabets are used irregularly, depending on the plaintext used. This cipher uses a keyed array of letters to make a digraphic cipher which is easy to use in the field. He invented a steganographic cipher in which each letter was represented as a word taken from a succession of columns. world.std.com /~cme/html/timeline.html   (3709 words)

M-94 CSP-488 Navy Disk Cypher (duplicate of the M-94) and disk #17 R = "ARMYOFTHEUSZJXDPCWGQIBKLNV" So you can see that the "army" on a disk does not mean that the device is of Army origion. The disks are ordered by finding the letter after the letter "A", In the case of the letter R it is the seventeenth disk (there is no disk with two "A"s). www.pacificsites.com /~brooke/M94.shtml   (3709 words)

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