SHARK

In cryptography, SHARK is a block cipher identified as one of the predecessors of Rijndael (the Advanced Encryption Standard).

SHARK has a 64-bit block size and a 128-bit key size. It is a six round SP-network which alternates a key mixing stage with linear and non-linear transformation layers. The linear transformation uses an MDS matrix representing a Reed-Solomon error correcting code in order to guarantee good diffusion. The nonlinear layer is composed of eight 8×8-bit S-boxes based on the function F(x) = x⁻¹ over GF(2⁸).

Five rounds of a modified version of SHARK can be broken using an interpolation attack (Jakobsen and Knudsen, 1997).

See also

References

Shark (helmet manufacturer)

Shark is a French company that produces motorcycle helmets, which was founded in 1986 in Marseille, France.

Helmets

Headquartered in Marseilles and with over 600 employees, SHARK helmets are distributed by a network of over 5,000 sales outlets worldwide.

External links

Cryptanalysis of the Enigma

Cryptanalysis of the Enigma enabled the western Allies in World War II to read substantial amounts of secret Morse-coded radio communications of the Axis powers that had been enciphered using Enigma machines. This yielded military intelligence which, along with that from other decrypted Axis radio and teleprinter transmissions, was given the codename Ultra. This was considered by western Supreme Allied Commander Dwight D. Eisenhower to have been "decisive" to the Allied victory.

The Enigma machines were a family of portable cipher machines with rotor scramblers. Good operating procedures, properly enforced, would have made the cipher unbreakable. However, most of the German armed and secret services and civilian agencies that used Enigma employed poor procedures and it was these poor operating procedures that allowed the Enigma machines to be reverse engineered and the ciphers to be read.

The German plugboard-equipped Enigma became Nazi Germany's principal crypto-system. It was broken by the Polish General Staff's Cipher Bureau in December 1932—with the aid of French-supplied intelligence material that had been obtained from a German spy. Shortly before the outbreak of World War II, the Polish Cipher Bureau initiated the French and British into its Enigma-breaking techniques and technology at a conference held in Warsaw.

Song

A song is a single (and often standalone) work of music intended to be sung by the human voice with distinct and fixed pitches and patterns using sound and silence and a variety of forms that often include the repetition of sections. Written words created specifically for music or for which music is specifically created, are called lyrics. If a pre-existing poem is set to composed music in classical music it is an art song. Songs that are sung on repeated pitches without distinct contours and patterns that rise and fall are called chants. Songs in a simple style that are learned informally are often referred to as folk songs. Songs that are composed for professional singers are called popular songs. These songs, which have broad appeal, are often composed by professional songwriters, composers and lyricists. Art songs are composed by trained classical composers for concert performances. Songs are performed live and recorded. Songs may also appear in plays, musical theatre, stage shows of any form, and within operas.

Song (disambiguation)

A song is a musical composition for voice or voices.

Song or songs or The Song may also refer to:

Music

Albums

Songs

Song (airline)

Song, LLC was a low-cost air service within an airline brand owned and operated by Delta Air Lines from 2003 to 2006.

Song's main focus was on leisure traffic between the northeastern United States and Florida, a market where it competed with JetBlue Airways. It also operated flights between Florida and the West Coast, and from the Northeast to the west coast.

Song's aircraft were fitted with leather seats and free personal entertainment systems at every seat, with audio MP3 programmable selections, trivia games that could be played against other passengers, a flight tracker, and satellite television (provided by the DISH Network). Song offered free beverages, but charged for meals and liquor. Both brand-name snack boxes and healthy organic meals were offered. The flight safety instructions were sung or otherwise artistically interpreted, depending on the cabin crew. In addition to crew uniforms designed by Kate Spade, customized cocktails created by nightlife impresario Rande Gerber and an in-flight exercise program designed by New York City fitness guru David Barton, the airline created its own distinct mark in the industry. The Song brand was placed on more than 200 flights a day which carried over ten million passengers.