User:Holly Eskew/sandbox

Quantum Cryptography
User:Holly Eskew Data Encryption Standard (DES) v. Vernam Cipher--Hols 15:10, 29 September 2005 (UTC) []== The Art of Cryptography ==  User talk:Holly Eskew From Wikipedia, the free encyclopedia:

Data Encryption Standard (DES) v. Vernam Cipher
The Cipher of Ché Guevara: When in 1967 the Bolivian army captured and executed the revolutionary Ché Guevara, they found on his body a worksheet showing how he prepared a message for transmission to Cuban president Fidel Castro. Guevara used the unbreakable cipher invented by Gilbert Vernam in 1918. The letters of Guevara's message (in Spanish) were first translated into one- and two-digit decimal numbers by a fixed rule, namely: A6 E8 I39 M70 Q71 U52 Y1 B38 F30 J31 N76 R58 V50 Z59 C32 G36 K78 O9 S2 W56 D4 H34 L72 P79 T0 X54. By itself this procedure would have provided virtually no protection. The message digits were then strung together in convenient five-digit blocks. They became the top line of each three-line group on the worksheet. The middle line of each group is the key, a sequence of random digits known only to Guevara and Castro.

Next the message and key were added (without carries) to produce a cryptogram, forming the bottom line of each three-line group. Because of the addition of the random key digits, this cryptogram is itself a random decimal sequence, carrying no information about the original message, except to someone who know the key. The cryptogram was then transmitted to Cuba by an insecure channel such as shortwave radio. At the receiving end, Castros cipher office would have subtracted the same random key digits, reconstructing the number sequence in the top row, and then would have translated the numbers back into the letters of the message.

Many spies and diplomats have used the Vernam cipher throughout the 20th century. The key, rather than consisting of decimal digits, can be a long random sequence of the binary digits 0 and 1, and the additions and subtractions would be carried out in base 2 by machine, rather than in base 10 by hand. Nevertheless, the key must still be hand-carried from the place where it is generated to the places where it will be used, and it must be assiduously guarded during all phases of delivery and storage to prevent it from falling into the hands of an adversary.

Further Reading: THE CODEBREAKERS: THE STORY OF SECRET WRITING. David Kahn. Macmillian, 1967 MODERN CRYPTOLOGY: A TUTORIAL. Gilles Brassard in Lecture Notes in Computer Science, Vol. 325. Springer-Verlag, 1988. QUANTUM CRYPTOGRAPHY BASED ON BELLS THEOREM. Arthur K. Ekert in Physical Review Letters, Vol. 67, No. 6, pages 661-663; August 5, 1991. EXPERIMENTAL QUANTUM CRYPTOGRAPHY. Charles H. Bennett, Francois Bessette, Gilles Brassard, Louis Salvail and John Smolin in Journal of Cryptology, Vol. 5, No. 1, pages 3-28; 1992. QUANTUM CRYPTOGRAPHY WITHOUT BELLS THEOREM. Charles H. Bennett, Gilles Brassard and N. David Mermin in Physical Review Leters, Vol. 68, No. 5, pages 557-559; February 3, 1992.

Contents [hide]
1 ♦ 2 speech 3 symbols that represent whole words or vowl sounds that have meaning 4 Template:H:h 5 cyrpto-standards are changing, code talk is too; symbols tare taking over 6 The Art of Cryptography & Quantum Cryptography link to: Special:Contribution/UserTalk:Holly_Eskew 7 The Art of Cryptography

[Speech]
2 speech holly Kāwaʻu, ʻaiea.

[Symbols]
3 symbols that represent whole words or vowl sounds that have meaning

[H:h (h-values)]
Deaf community distinguishes between "D" for cultural style and little "d" for the physical.

[Code Talk]
5 cyrpto-standards are changing, ☠ code talk is too:

DATA ENCRYPTION STANDARD (DES) v. VERNAM CIPHER

[Quantum Crypotography]
6 The Art of Cryptography & Quantum Cryptography link to: Special:Contribution/UserTalk:Holly_Eskew The art of cryptography began at least 2,500 years ago and has played an important role in history ever since. Perhpas one of the most famous cryptograms, the Zimmermann Note, propelled the U.S. into World War I. When the cryptogram was broken in 1917, Americans learned that Germany had tried to entice Mexico to join its war effort by promisiing Mexico territories in the U.S.

Around this time Gilbert S. Vernam of American Telphone and Telegraph Company and Major Joseph O. Mauborgne of the U.S. Army Signal Corps developed the first truly unbreakable code called the Vernam cipher. One distinctive feature of the code is its need for a key that is as long as the message being transmitted and is never reused to send another message. (The Vernam cipher is also known as the one-time pad from the practice of furnishing the key to spies in the form of a tear-off pad, each sheet of which was to be used once and then carefully destroyed.) The discovery of the Vernam cipher did not create much of a stir at the time, probably because the cipher's unbreakability was not definitively proved until later and because its massive key requirements made it impractical for general use.

Because of this limitation, soldiers and dipolmats continued to rely on weaker ciphers using shorter keys. Consequently, during World War II, the Allies were able to read most of the secret messages transmitted by the Germans and Japanese. These ciphers, though breakable, were by no means easy to crack. Indeed, the formidable task of breaking increasingly sophisticated cipphers was one of the factors that stimulated the development of electronic computers.

Academic interest in cryptology grew more intense in the mid-1970's, when Whitefield Diffie, Martin E. Hellman and Ralph C. Merkly, then at Stanford University, discovered the principle of public-key cryptography (PKC). Soon afterward, in 1977, Ronald L. Rivest, Adi Shamir and Leonard M. Adleman, then at the Massachusetts Institute of Technology, devised a practical implementation [see "The Mathematics of Public-Key Cryptography," by Martin E. Hellman; SCIENTIFIC AMERICAN, August 1979].

title=User_talk:Holly_Eskew

Data Encryption Standard (DES) v. Vernam Cipher== The Art of Cryptography & Quantum Cryptography link to: Special:Contribution/UserTalk:Holly_Eskew ==

[The Art of Cryptography]
7 The Art of Cryptography "see also:" Quantum Cryptography "link to:" The Art of Cryptography. [1] --Hols 13:47, 29 September 2005 (UTC)

The art of cryptography began at least 2,500 years ago and has played an important role in history ever since. Perhpas one of the most famous cryptograms, the Zimmermann Note, propelled the U.S. into World War I. When the cryptogram was broken in 1917, Americans learned that Germany had tried to entice Mexico to join its war effort by promisiing Mexico territories in the U.S. Around this time Gilbert S. Vernam of American Telphone and Telegraph Company and Major Joseph O. Mauborgne of the U.S. Army Signal Corps developed the first truly unbreakable code called the Vernam cipher. One distinctive feature of the code is its need for a key that is as long as the message being transmitted and is never reused to send another message. (The Vernam cipher is also known as the one-time pad from the practice of furnishing the key to spies in the form of a tear-off pad, each sheet of which was to be used once and then carefully destroyed.) The discovery of the Vernam cipher did not create much of a stir at the time, probably because the cipher's unbreakability was not definitively proved until later and because its massive key requirements made it impractical for general use.

Because of this limitation, soldiers aned dipolmats continued to rely on weaker ciphers using shorter keys. Consequently, during World War II, the Allies were able to read most of the secret messages transmitted by the Germans and Japanese. These ciphers, though breakable, were by no means easy to crack. Indeed, the formidable task of breaking increasingly sophisticated cipphers was one of the factors that stimulated the development of electronic computers.

Academic interest in cryptology grew more intense in the mid-1970's, when Whitefield Diffie, Martin E. Hellman and Ralph C. Merkly, then at Stanford University, discovered the principle of public-key cryptography (PKC). Soon afterward, in 1977, Ronald L. Rivest, Adi Shamir and Leonard M. Adleman, then a the Massachusetts Institute of Technology, devised a practical implementation [see "The Mathematics of Public-Key Cryptography," by Martin E. Hellman; SCIENTIFIC AMERICAN, August 1979].

title=User_talk:Holly_Eskew

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This page was last modified 13:58, 29 September 2005. All text is available under the terms of the GNU Free Documentation License (see Copyrights for details). About Wikipedia Disclaimers --Hols 15:20, 29 September 2005 (UTC)