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Arabic Letter Frequency
The frequency of letters in text has often been studied for use in cryptanalysis, and frequency analysis in particular. No language has an exact letter frequency distribution, as all writers write slightly differently. As a rule texts in different languages using the Arabic script (e.g. Arabic, Ottoman Turkish, Persian and Urdu) will have different letter frequencies, most obviously in the case of letters which are only used in some languages (e.g. the Persian letters پ, چ, گ, which are not used to write in Arabic). Methods encoding the most frequent letters with the shortest symbols were pioneered by telegraph codes, and are used in modern data-compression techniques such as Huffman coding. Arabic letters The Arabic alphabet consists of 28 primary letters, these are letters 1 to 28 in Table 1. The eight modified letters listed in positions 29 to 36 in the same table are used just the same. If these 8 modified forms are folded into the primary list based on shape or pho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptanalysis
Cryptanalysis (from the Greek ''kryptós'', "hidden", and ''analýein'', "to analyze") refers to the process of analyzing information systems in order to understand hidden aspects of the systems. Cryptanalysis is used to breach cryptographic security systems and gain access to the contents of encrypted messages, even if the cryptographic key is unknown. In addition to mathematical analysis of cryptographic algorithms, cryptanalysis includes the study of side-channel attacks that do not target weaknesses in the cryptographic algorithms themselves, but instead exploit weaknesses in their implementation. Even though the goal has been the same, the methods and techniques of cryptanalysis have changed drastically through the history of cryptography, adapting to increasing cryptographic complexity, ranging from the pen-and-paper methods of the past, through machines like the British Bombes and Colossus computers at Bletchley Park in World War II, to the mathematically advanced comput ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Sealed Nectar
''Ar-Raheeq Al-Makhtum'' ( ar, الرحيق المختوم; ), is a seerah book, or biography of the Prophet, which was written by Safiur Rahman Mubarakpuri. This book was awarded first prize by the Muslim World League in a worldwide competition on the biography of the Prophet held in Mecca in 1979. History Following in the year 1396 AH, Rabita organized a book writing competition on Islamic Seerat-Un-Nabi. Many writers from different countries participated in this global competition with interest. Out of 171 manuscripts, the book Ar-Raheeq Al-Makhtum''' won the first prize. In writing the book, the author has given a series of historical events and in describing them he has arranged the titles of different chapters in chronological order. In cases where there are differences of opinion in different texts, the author reviews everything and mentions what he thinks is correct. In cases where the author does not find the information of dissenters to be correct, he gives an indica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ibn Kathir
Abū al-Fiḍā’ ‘Imād ad-Dīn Ismā‘īl ibn ‘Umar ibn Kathīr al-Qurashī al-Damishqī (Arabic: إسماعيل بن عمر بن كثير القرشي الدمشقي أبو الفداء عماد; – 1373), known as Ibn Kathīr (, was a highly influential Arab historian, exegete and scholar during the Mamluk era in Syria. An expert on ''tafsir'' (Quranic exegesis) and ''fiqh'' (jurisprudence), he wrote several books, including a fourteen-volume universal history titled Al-Bidaya wa'l-Nihaya.Ludwig W. Adamec (2009), ''Historical Dictionary of Islam'', p.138. Scarecrow Press. . His ''tafsir'' is recognized for its critical approach to ''Israʼiliyyat'', especially among Western Muslims and Wahhabi scholars. His methodology largely derives from his teacher Ibn Taymiyyah, and differs from that of other earlier renowned exegetes such as Tabari. For that reason, he is mostly considered an Athari, despite being a Shafi'i jurist. Biography His full name was () and had the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unicode
Unicode, formally The Unicode Standard,The formal version reference is is an information technology Technical standard, standard for the consistent character encoding, encoding, representation, and handling of Character (computing), text expressed in most of the world's writing systems. The standard, which is maintained by the Unicode Consortium, defines as of the current version (15.0) 149,186 characters covering 161 modern and historic script (Unicode), scripts, as well as symbols, emoji (including in colors), and non-visual control and formatting codes. Unicode's success at unifying character sets has led to its widespread and predominant use in the internationalization and localization of computer software. The standard has been implemented in many recent technologies, including modern operating systems, XML, and most modern programming languages. The Unicode character repertoire is synchronized with Universal Coded Character Set, ISO/IEC 10646, each being code-for-code id ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency Analysis
In cryptanalysis, frequency analysis (also known as counting letters) is the study of the frequency of letters or groups of letters in a ciphertext. The method is used as an aid to breaking classical ciphers. Frequency analysis is based on the fact that, in any given stretch of written language, certain letters and combinations of letters occur with varying frequencies. Moreover, there is a characteristic distribution of letters that is roughly the same for almost all samples of that language. For instance, given a section of English language, , , and are the most common, while , , and are rare. Likewise, , , , and are the most common pairs of letters (termed ''bigrams'' or ''digraphs''), and , , , and are the most common repeats. The nonsense phrase " ETAOIN SHRDLU" represents the 12 most frequent letters in typical English language text. In some ciphers, such properties of the natural language plaintext are preserved in the ciphertext, and these patterns have the pote ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Huffman Coding
In computer science and information theory, a Huffman code is a particular type of optimal prefix code that is commonly used for lossless data compression. The process of finding or using such a code proceeds by means of Huffman coding, an algorithm developed by David A. Huffman while he was a Sc.D. student at MIT, and published in the 1952 paper "A Method for the Construction of Minimum-Redundancy Codes". The output from Huffman's algorithm can be viewed as a variable-length code table for encoding a source symbol (such as a character in a file). The algorithm derives this table from the estimated probability or frequency of occurrence (''weight'') for each possible value of the source symbol. As in other entropy encoding methods, more common symbols are generally represented using fewer bits than less common symbols. Huffman's method can be efficiently implemented, finding a code in time linear to the number of input weights if these weights are sorted. However, although opt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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