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.

Carnival Sensation

Carnival Sensation (formerly Sensation) is a Fantasy-class cruise ship operated by Carnival Cruise Line. Built by Kværner Masa-Yards at its Helsinki New Shipyard in Helsinki, Finland, she was floated out on November, 1, 1993, and christened Sensation by four Carnival Vice Presidents: Vicki L. Freed, Roberta Jacoby, Cherie Weinstein and Geri Donnelly.

During 2007, in common with all of her Fantasy-class sisters, she had the prefix Carnival added to her name.

The third ship to be built in the Fantasy class, Carnival Sensation returned to active cruise service on February 12, 2009, after an extensive drydocking and refit. During the refit, 98 private balconies were added to former ocean view rooms. An adults only sunning area called Serenity was added to Promenade Deck, aft. A children's water park area was installed on Verandah Deck, aft, in an area formerly used as a pool and sunning area. The Carnival Sensation's main pool area on Lido Deck, midship, was renovated and the water slide was removed. Other renovations included new carpeting in public spaces and in her main dining rooms, and a 4-story tall "Carnival Waterworks" waterslide was added at the aft of the ship.

Sensation (album)

Sensation, an album by Anúna, was released in 2006 on the Danú label. All music featured on the disc is original, written by the Irish composer Michael McGlynn.

Track listing

All titles are originals, composed and arranged by Michael McGlynn

Personnel

Guest musicians

Sensation (mango)

The 'Sensation' mango is a late-season mango cultivar that originated in south Florida and was grown on a commercial scale.

History

The original tree grew from a seed planted in North Miami, Florida in 1935. For some decades the parents of 'Sensation' were unknown, but a 2005 pedigree analysis estimated that 'Sensation' was likely a cross between 'Haden' and 'Brooks'. The tree first fruited in 1941. In 1949 it was named and the tree was moved to the Carmichael nursery in Perrine, Florida by J.B. Carmichael, where it began to be propagated.

Despite possessing outstanding color and good production characteristics, 'Sensation' had a drawback due to problems with uneven ripening. After receiving some initial commercial plantings, it fell out of favor as a commercial cultivar and did not become a popular dooryard cultivar in Florida. Some 'Sensation' trees remain in commercial groves.

'Sensation' trees are planted in the collections of the USDA's germplasm repository in Miami, Florida, the University of Florida's Tropical Research and Education Center in Homestead, Florida, and the Miami-Dade Fruit and Spice Park, also in Homestead.

Combustion

Combustion /kəm�?bʌs.t�?ən/ or burning is a high-temperature exothermic redox chemical reaction between a fuel and an oxidant, usually atmospheric oxygen, that produces oxidized, often gaseous products, in a mixture termed as smoke. Combustion in a fire produces a flame, and the heat produced can make combustion self-sustaining. Combustion is often a complicated sequence of elementary radical reactions. Solid fuels, such as wood, first undergo endothermic pyrolysis to produce gaseous fuels whose combustion then supplies the heat required to produce more of them. Combustion is often hot enough that light in the form of either glowing or a flame is produced. A simple example can be seen in the combustion of hydrogen and oxygen into water vapor, a reaction commonly used to fuel rocket engines. This reaction releases 242 kJ/mol of heat and reduces the enthalpy accordingly (at constant temperature and pressure):

Combustion of an organic fuel in air is always exothermic because the double bond in O₂ is much weaker than other double bonds or pairs of single bonds, and therefore the formation of the stronger bonds in the combustion products CO₂ and H₂O results in the release of energy. The bond energies in the fuel play only a minor role, since they are similar to those in the combustion products; e.g., the sum of the bond energies of CH₄ is nearly the same as that of CO₂. The heat of combustion is approximately -418 kJ per mole of O₂ used up in the combustion reaction, and can be estimated from the elemental composition of the fuel.