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Virginia Beach, officially the City of Virginia Beach, is an independent city located on the southeastern coast of Virginia, United States.The population was 459,470 at the 2020 census. Although mostly suburban in character, it is the most populous city in Virginia, fifth-most populous city in the Mid-Atlantic and the 42nd-most populous city in the U.S.
- 10 ft (3 m)
- None (Independent city)
- 23450-23467, 23471, 23479
- Virginia
Piedmont region of Virginia. Coordinates: 38°24′28.9″N 77°43′6.5″W. The Piedmont region of Virginia is a part of the greater Piedmont physiographic region which stretches from the falls of the Potomac, Rappahannock, and James Rivers to the Blue Ridge Mountains. The region runs across the middle of the state from north to south ...
Virginia, officially the Commonwealth of Virginia, is a state in the Southeastern and Mid-Atlantic regions of the United States between the Atlantic Coast and the Appalachian Mountains.The state's capital is Richmond and its most populous city is Virginia Beach, though its most populous subdivision is Fairfax County, part of Northern Virginia, where slightly over a third of Virginia's ...
- 42,774.2 sq mi (110,785.67 km²)
- Virginia Beach
- Colony of Virginia
- 6 Democrats, 5 Republicans (list)
Virginia Falls (Slave: Nailicho[1]) is a waterfall in Nahanni National Park Reserve, Northwest Territories, Canada. It is on the South Nahanni River, at an elevation of 500 m (1,600 ft).[2] It is located 120 km (75 mi) from the Yukon border.[3] An American adventurer and businessman from Long Island, New York, named Fenley Hunter, under the ...
- History
- Description
- Algebraic Description
- Cryptanalysis
- Variants
- References
The very first well-documented description of a polyalphabetic cipher was by Leon Battista Alberti around 1467 and used a metal cipher disk to switch between cipher alphabets. Alberti's system only switched alphabets after several words, and switches were indicated by writing the letter of the corresponding alphabet in the ciphertext. Later, Johann...
In a Caesar cipher, each letter of the alphabet is shifted along some number of places. For example, in a Caesar cipher of shift 3, a would become D, b would become E, y would become Band so on. The Vigenère cipher has several Caesar ciphers in sequence with different shift values. To encrypt, a table of alphabets can be used, termed a tabula recta...
Vigenère can also be described algebraically. If the letters A–Z are taken to be the numbers 0–25 (A = ^ 0 {\displaystyle A\,{\widehat {=}}\,0} , B = ^ 1 {\displaystyle B\,{\widehat {=}}\,1} , etc.), and addition is performed modulo 26, Vigenère encryption E {\displaystyle E} using the key K {\displaystyle K} can be written as 1. C i = E K ( M i ) ...
The idea behind the Vigenère cipher, like all other polyalphabetic ciphers, is to disguise the plaintext letter frequency to interfere with a straightforward application of frequency analysis. For instance, if P is the most frequent letter in a ciphertext whose plaintext is in English, one might suspect that P corresponds to e since e is the most f...
Running key
The running keyvariant of the Vigenère cipher was also considered unbreakable at one time. For the key, this version uses a block of text as long as the plaintext. Since the key is as long as the message, the Friedman and Kasiski tests no longer work, as the key is not repeated. If multiple keys are used, the effective key length is the least common multiple of the lengths of the individual keys. For example, using the two keys GO and CAT, whose lengths are 2 and 3, one obtains an effective k...
Variant Beaufort
A simple variant is to encrypt by using the Vigenère decryption method and to decrypt by using Vigenère encryption. That method is sometimes referred to as "Variant Beaufort". It is different from the Beaufort cipher, created by Francis Beaufort, which is similar to Vigenère but uses a slightly modified enciphering mechanism and tableau. The Beaufort cipher is a reciprocal cipher.
Gronsfeld cipher
Despite the Vigenère cipher's apparent strength, it never became widely used throughout Europe. The Gronsfeld cipher is a variant created by Count Gronsfeld (Josse Maximilaan van Gronsveldné van Bronckhorst); it is identical to the Vigenère cipher except that it uses just 10 different cipher alphabets, corresponding to the digits 0 to 9). A Gronsfeld key of 0123 is the same as a Vigenere key of ABCD. The Gronsfeld cipher is strengthened because its key is not a word, but it is weakened becaus...
Sources
1. Beutelspacher, Albrecht (1994). "Chapter 2". Cryptology. translation from German by J. Chris Fisher. Washington, DC: Mathematical Association of America. pp. 27–41. ISBN 0-883-85504-6. 2. Singh, Simon (1999). "Chapter 2: Le Chiffre Indéchiffrable". The Code Book. Anchor Book, Random House. ISBN 0-385-49532-3. 3. Helen F. Gaines (18 November 2014). Cryptanalysis: A Study of Ciphers and Their Solution. Courier Corporation. p. 117. ISBN 978-0-486-80059-2. 4. Mendelsohn, Charles J (1940). "Bla...
- LXFOPVEFRNHR
- attackatdawn
- LEMONLEMONLE
Denali (/ d ə ˈ n ɑː l i /; also known as Mount McKinley, its former official name) is the highest mountain peak in North America, with a summit elevation of 20,310 feet (6,190 m) above sea level.It is the tallest mountain in the world from base-to-peak on land, measuring 18,000 ft (5,500 m), and Earth's highest mountain north of 43 N.
University of Virginia. / 38.03556°N 78.50333°W / 38.03556; -78.50333. The University of Virginia ( UVA) is a public research university in Charlottesville, Virginia, United States. It was founded in 1819 by Thomas Jefferson and contains his Academical Village, a UNESCO World Heritage Site.
