DOCSLIB.ORG

7-Bit ASCII Code

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
7-Bit ASCII Code Appendix A 7-bit ASCII code 000 001 010 011 100 101 110 111 0000 nul soh stx etx eat enq ack bel 0001 bs ht nl vt np cr so si 0010 dIe del de2 dc3 dc4 nak syn etb VVll can em SUD esc LS gs rs us , 0100 space ! " # $ % & 0101 () * + , - / 0110 0 1 2 3 4 5 6 7 0111 8 9 : ; < = > ? 1000 @ A B C 0 E F G 1001 HI J KLM N 0 1010 P Q R S T U V W A - 1011 XYZ [ \ ] , -- 1100 a b c d e f g 1101 h i j k 1 ill n 0 1110 P q r s t u v w -- 1111 x y z { I ) del Row numbers represent the 4-bit prefix, and the column numbers represent the 3-bit suf­ fix. The first 32 ASCII codes and the last ASCII code are control codes, whIch are not displayable. Appendix B SMA-512 Constants (in hexadecimal) i Ki i Ki i Ki 0 428a2f98d728ae22 1 7137449123ef65cd 2 b5cOfbcfec4d3b2f ':l ,~Q1 o o--u-a-, A -v rv c v- _0C r-'~Qh~-'Q r:; ~Qf'11 f'1hhn~r1n1Q 6 923f82a4afl94f9b 7 ablc5ed5da6d8118 8 d807aa98a3030242 9 12835b0145706fbe 10 243185be4ee4b28c 11 550c7dc3d5ffb4e2 12 72be5d74f27b896f 13 80deblfe3b1696bl 14 9bdc06a725c71235 15 c19bfl74cf692694 16 e49b69c1gef14ad2 17 efbe4786384f25e3 18 Ofc19dc68b8cd5b5 19 240calcc77ac9c65 20 2de92c6f592b0275 21 4a7484aa6ea6e483 22 5cbOa9dcbd41fbd4 23 76f988da831153b5 24 983e5152ee66dfab 25 a831c66d2db43210 26 b00327c898fb213f 27 bf597fc7beefOee4 28 c6eOObf33da88fc2 29 d5a7914793 Oaa 725 30 06ca6351e003826f 31 142929670aOe6e70 32 27b70a8546d22ffc 33 2elb21385c26c926 34 4d2c6dfc5ac42aed 35 53380d139d95b3df 36 650a73548baf63de 37 766aOabb3c77b2a8 38 81c2c92e47edaee6 39 92 722c851482353b 40 a2bfe8a14cfl 0364 41 a81a664bbc423001 42 c24b8b70dOf89791 43 c76c5la30654be30 44 d192e819d6ef5218 45 d69906245565a910 46 f40e35855771202a 47 106aa07032bbdlb8 48 19a4cl16b8d2dOc8 49 le376c085141ab53 50 2748774cdf8eeb9 9 51 34bObcb5e19b48a8 52 391cOcb3c5c95a63 53 4ed8aa4ae3418acb 54 5b9cca4f7763e373 55 682e6ff3d6b2b8a3 56 748f82ee5defb2fc 57 78a5636f43172f60 58 84c87814alfOab72 59 8cc702081a643gec 60 90befffa23631e28 61 a4506cebde82bde9 62 bef9a3f7b2c67915 63 c67178f2e372532b 64 ca273eceea26619c 65 d186b8c721cOc207 66 eada7dd6cdeOeble 67 f57d4f7fee6ed178 68 06f067aa72176fba 69 Oa637dc5a2c898a6 70 113f9804bef90dae 71 Ib710b35131c471b 72 28db77f523047d84 73 32caab7b40c72493 74 3cgebeOa15c9bebc 75 431d67c49cl00d4c 76 4cc5d4becb3e42b6 77 597f299cfc657e2a 78 5fcb6fab3ad6faec 79 6c44198c4a475817 Appendix C Data Compression using ZIP ZIP is a simple matching algorithm using two sliding windows, called the base win­ dow and the look-ahead window. These two windows are placed side-by-side on the data file, where the look-ahead window goes ahead of the base window. ZIP scans the entIre file by slIdmg these two wmdows and encodmg data on the fly. In par­ tIcular, ZIP finds the longest prefix s of the data stnng contamed in the look-ahead window that also appears in the base window. This string in the look-ahead window (if found) is a copy of s in the base window, and so it can be uniquely identified by two attributes: (1) the distance between the location of the first character of s in the base wmdow and the locatIOn of the first character m the look-ahead wmdow and (2) the length of s. If the space needed to hold the values of these two attnbutes IS smaller than the space needed to hold s, we obtam a savmg of space. To implement this idea, we will need to distinguish the binary values of the two attributes from normal encodings of characters. Suppose the data file is encoded usmg the 8-blt ASCII code set. If the first bIt IS used as a panty bIt, then It could be eIther 0 or 1. The first bIt of the bmary strmg representmg the two attnbutes can also be eIther 0 or 1. Thus, to make a dlstmctIon, we add an extra bIt of 1 m front of each ASCII code to yield a 9-bit extended ASCII code and add an extra bit of 0 in front of the binary string representing the two attributes. This simple encoding uniquely identifies the original data file. In partIcular, let W1 denote the number of characters the base wmdow can hold, d d where 2 -1 < Wj < 2 for some d > 1. Let W2 denote the number of characters the 1 look-ahead window can hold, where 21- < W2 ::; 2/ for some l with 1 ::; l::; d. This produces a (d + l + 1)-bit binary encoding for s, where the first bit is 0 (used as an indicator), the next d bits represent the distance, and the last l bits represent the length. For convenience, we will call this (d + l + 1)-bit code a location code. A locatIOn code IS easIly dlstmgUlshable from any 9-blt extended ASCII code because a locatIOn code has a fixed length and an mdlcator 0 dIfferent from the indicator in a 9-bit extended ASCII code. In other words, given a compressed file using this encoding method, it can be uniquely and easily "uncompressed" back to its original ASCII format. The proof is left to the reader (see the Exercise). Thus, as long as d +l+ 1 < 8k, where k = lsi, ZIP may save space. ZIP then shifts both of the 354 C Data Compression using ZIP base window and the look-ahead window to the right max{I,k} times and repeats the same procedure until the look-ahead window is shifted out of the data file. For example, let WI = 18 and Wz = 7. Then d = 5 and I = 3. Let us consider the following text string: "a loop containing a loop is a nested loop" Denote by nb, the binary representation of positive integer n. Running ZIP on this character string produces the following output (see Fig. C.l ): where each letter and space in the output string is encoded by a 9-bit extended ASCII code. For clarity, we do not spell out the location code in binary. The length of the "compressed" string in binary is therefore equal to 18 x 9 + 9 + 11 x 9 + 9 = 279 bIts, and the length of the ongmal character stnng encoded m the 8-blt ASCII code set IS equal to 41 x 8 = 328 bIts. Thus, ZIP has compressed the ongmal data stnng to a shorter bmary string, base window look-ahead input a loop containing a loop is a nested loop 7 11 basewindQw a loop containing a loop is a nested 16 output a loop containing 017b7b is a nested 016b5" Fig. C.I A demonstration of a ZIP process To decode a compressed file, ZIP scans It from the begmnIng, removes the lead­ mg 1 from each 9-blt extended code, and replaces each 9-blt code WIth leadmg 0 by the correspondmg character substrmg using the dIstance and length attnbutes. Exercise Show why the IO-bit code defined in Section C is easily distinguishable from the extended 9-bit ASCII code. That is, given a compressed file using this encoding method, show it can be uniquely and easily "uncompressed" back to its original ASCII format AppendixD Base64 Encoding Base64 encoding represents a 6-bit binary string using a printable character (see Table D.l), where a 6-bit value of 0 to 25 represents a upper-case letter A to Z correspondingly; a 6-bit value of 26 to 51 represents a lower-case letter a to z cor­ respondingly; a 6-bit value of 52 to 61 represents a digit 0 to 9 correspondingly; and the last two 6-bit values of 62 and 63 represent H+" and HI" respectively. Trans­ mitted in ASCII format, this means that every 6-bit string is replaced with an 8-bit string. Table D.I Base64 encoding 6-bitvalue 0 I 2 3 4 5 6 7 8 9 10 II 12 13 14 15 16 17 18 19 character encoding ABC DEFGHI J KLMN 0 P Q RST 6-bit value 20 21 22 23 24 25 26 27 28 29 31 31 32 33 34 35 36 37 38 39 character encoding U V W Z Y Z abc d e f g h i j k I ill n 6-bit value 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 character encoding 0 p q r stu v w z y z 0 I 2 3 4 5 6 7 6-bit value 60 61 62 63 character encoding 8 9 + / In addition, Base64 encoding uses character "-" as a special indicator. Using Base64 encoding, a binary string is converted to a character string as follows: Case I: The binary data consists of only one byte. Pad it at the end with 16 O's to extend it to a 24-bit string. This 24-bit string is then converted to a Base64 string of four characters, wIth "==" beIng the last two characters. ThIS IndIcates that only the first two characters are to be decoded, and the suffix 0000 IS dIscarded. Case 2: The binary data consists of only two bytes. Pad it at the end with eight O's to extend it to a 24-bit string. This 24-bit string is then converted to a Base64 string of four characters, with "=" being the last character. This indicates that only the first three characters are to be decoded, and the suffix 00 IS dIscarded. Case 3: The bInary data consists of at least three bytes. Place the first three bytes of the binary data into a 24-bit buffer, where the first byte is placed in the most significant eight bits of the buffer, the second byte is placed in the middle, and the 356 D Base64 Encoding third byte in the least significant eight bits.
Load more

Recommended publications
  • A Quantitative Study of Advanced Encryption Standard Performance
    United States Military Academy USMA Digital Commons West Point ETD 12-2018 A Quantitative Study of Advanced Encryption Standard Performance as it Relates to Cryptographic Attack Feasibility Daniel Hawthorne United States Military Academy, [email protected] Follow this and additional works at: https://digitalcommons.usmalibrary.org/faculty_etd Part of the Information Security Commons Recommended Citation Hawthorne, Daniel, "A Quantitative Study of Advanced Encryption Standard Performance as it Relates to Cryptographic Attack Feasibility" (2018). West Point ETD. 9. https://digitalcommons.usmalibrary.org/faculty_etd/9 This Doctoral Dissertation is brought to you for free and open access by USMA Digital Commons. It has been accepted for inclusion in West Point ETD by an authorized administrator of USMA Digital Commons. For more information, please contact [email protected]. A QUANTITATIVE STUDY OF ADVANCED ENCRYPTION STANDARD PERFORMANCE AS IT RELATES TO CRYPTOGRAPHIC ATTACK FEASIBILITY A Dissertation Presented in Partial Fulfillment of the Requirements for the Degree of Doctor of Computer Science By Daniel Stephen Hawthorne Colorado Technical University December, 2018 Committee Dr. Richard Livingood, Ph.D., Chair Dr. Kelly Hughes, DCS, Committee Member Dr. James O. Webb, Ph.D., Committee Member December 17, 2018 © Daniel Stephen Hawthorne, 2018 1 Abstract The advanced encryption standard (AES) is the premier symmetric key cryptosystem in use today. Given its prevalence, the security provided by AES is of utmost importance. Technology is advancing at an incredible rate, in both capability and popularity, much faster than its rate of advancement in the late 1990s when AES was selected as the replacement standard for DES. Although the literature surrounding AES is robust, most studies fall into either theoretical or practical yet infeasible.
    [Show full text]
  • Base64 Character Encoding and Decoding Modeling
    Base64 Character Encoding and Decoding Modeling Isnar Sumartono1, Andysah Putera Utama Siahaan2, Arpan3 Faculty of Computer Science,Universitas Pembangunan Panca Budi Jl. Jend. Gatot Subroto Km. 4,5 Sei Sikambing, 20122, Medan, Sumatera Utara, Indonesia Abstract: Security is crucial to maintaining the confidentiality of the information. Secure information is the information should not be known to the unreliable person, especially information concerning the state and the government. This information is often transmitted using a public network. If the data is not secured in advance, would be easily intercepted and the contents of the information known by the people who stole it. The method used to secure data is to use a cryptographic system by changing plaintext into ciphertext. Base64 algorithm is one of the encryption processes that is ideal for use in data transmission. Ciphertext obtained is the arrangement of the characters that have been tabulated. These tables have been designed to facilitate the delivery of data during transmission. By applying this algorithm, errors would be avoided, and security would also be ensured. Keywords: Base64, Security, Cryptography, Encoding I. INTRODUCTION Security and confidentiality is one important aspect of an information system [9][10]. The information sent is expected to be well received only by those who have the right. Information will be useless if at the time of transmission intercepted or hijacked by an unauthorized person [7]. The public network is one that is prone to be intercepted or hijacked [1][2]. From time to time the data transmission technology has developed so rapidly. Security is necessary for an organization or company as to maintain the integrity of the data and information on the company.
    [Show full text]
  • Unicode and Code Page Support
    Natural for Mainframes Unicode and Code Page Support Version 4.2.6 for Mainframes October 2009 This document applies to Natural Version 4.2.6 for Mainframes and to all subsequent releases. Specifications contained herein are subject to change and these changes will be reported in subsequent release notes or new editions. Copyright © Software AG 1979-2009. All rights reserved. The name Software AG, webMethods and all Software AG product names are either trademarks or registered trademarks of Software AG and/or Software AG USA, Inc. Other company and product names mentioned herein may be trademarks of their respective owners. Table of Contents 1 Unicode and Code Page Support .................................................................................... 1 2 Introduction ..................................................................................................................... 3 About Code Pages and Unicode ................................................................................ 4 About Unicode and Code Page Support in Natural .................................................. 5 ICU on Mainframe Platforms ..................................................................................... 6 3 Unicode and Code Page Support in the Natural Programming Language .................... 7 Natural Data Format U for Unicode-Based Data ....................................................... 8 Statements .................................................................................................................. 9 Logical
    [Show full text]
  • SAS 9.3 UTF-8 Encoding Support and Related Issue Troubleshooting
    SAS 9.3 UTF-8 Encoding Support and Related Issue Troubleshooting Jason (Jianduan) Liang SAS certified: Platform Administrator, Advanced Programmer for SAS 9 Agenda Introduction UTF-8 and other encodings SAS options for encoding and configuration Other Considerations for UTF-8 data Encoding issues troubleshooting techniques (tips) Introduction What is UTF-8? . A character encoding capable of encoding all possible characters Why UTF-8? . Dominant encoding of the www (86.5%) SAS system options for encoding . Encoding – instructs SAS how to read, process and store data . Locale - instructs SAS how to present or display currency, date and time, set timezone values UTF-8 and other Encodings ASSCII (American Standard Code for Information Interchange) . 7-bit . 128 - character set . Examples (code point-char-hex): 32-Space-20; 63-?-3F; 64-@-40; 65-A-41 UTF-8 and other Encodings ISO 8859-1 (Latin-1) for Western European languages Windows-1252 (Latin-1) for Western European languages . 8-bit (1 byte, 256 character set) . Identical to asscii for the first 128 chars . Extended ascii chars examples: . 155-£-A3; 161- ©-A9 . SAS option encoding value: wlatin1 (latin1) UTF-8 and other Encodings UTF-8 and other Encodings Problems . Only covers English and Western Europe languages, ISO-8859-2, …15 . Multiple encoding is required to support national languages . Same character encoded differently, same code point represents different chars Unicode . Unicode – assign a unique code/number to every possible character of all languages . Examples of unicode points: o U+0020 – Space U+0041 – A o U+00A9 - © U+C3BF - ÿ UTF-8 and other Encodings UTF-8 .
    [Show full text]
  • JS Character Encodings
    JS � Character Encodings Anna Henningsen · @addaleax · she/her 1 It’s good to be back! 2 ??? https://travis-ci.org/node-ffi-napi/get-symbol-from-current-process-h/jobs/641550176 3 So … what’s a character encoding? People are good with text, computers are good with numbers Text List of characters “Encoding” List of bytes List of integers 4 So … what’s a character encoding? People are good with text, computers are good with numbers Hello [‘H’,’e’,’l’,’l’,’o’] 68 65 6c 6c 6f [72, 101, 108, 108, 111] 5 So … what’s a character encoding? People are good with text, computers are good with numbers 你好! [‘你’,’好’] ??? ??? 6 ASCII 0 0x00 <NUL> … … … 65 0x41 A 66 0x42 B 67 0x43 C … … … 97 0x61 a 98 0x62 b … … … 127 0x7F <DEL> 7 ASCII ● 7-bit ● Covers most English-language use cases ● … and that’s pretty much it 8 ISO-8859-*, Windows code pages ● Idea: Usually, transmission has 8 bit per byte available, so create ASCII-extending charsets for more languages ISO-8859-1 (Western) ISO-8859-5 (Cyrillic) Windows-1251 (Cyrillic) (aka Latin-1) … … … … 0xD0 Ð а Р 0xD1 Ñ б С 0xD2 Ò в Т … … … … 9 GBK ● Idea: Also extend ASCII, but use 2-byte for Chinese characters … … 0x41 A 0x42 B … … 0xC4 0xE3 你 0xC4 0xE4 匿 … … 10 https://xkcd.com/927/ 11 Unicode: Multiple encodings! 4d c3 bc 6c 6c (UTF-8) U+004D M “Müll” U+00FC ü 4d 00 fc 00 6c 00 6c 00 (UTF-16LE) U+006C l U+006C l 00 4d 00 fc 00 6c 00 6c (UTF-16BE) 12 Unicode ● New idea: Don’t create a gazillion charsets, and drop 1-byte/2-byte restriction ● Shared character set for multiple encodings: U+XXXX with 4 hex digits, e.g.
    [Show full text]
  • San José, October 2, 2000 Feel Free to Distribute This Text
    San José, October 2, 2000 Feel free to distribute this text (version 1.2) including the author’s email address ([email protected]) and to contact him for corrections and additions. Please do not take this text as a literal translation, but as a help to understand the standard GB 18030-2000. Insertions in brackets [] are used throughout the text to indicate corresponding sections of the published Chinese standard. Thanks to Markus Scherer (IBM) and Ken Lunde (Adobe Systems) for initial critical reviews of the text. SUMMARY, EXPLANATIONS, AND REMARKS: CHINESE NATIONAL STANDARD GB 18030-2000: INFORMATION TECHNOLOGY – CHINESE IDEOGRAMS CODED CHARACTER SET FOR INFORMATION INTERCHANGE – EXTENSION FOR THE BASIC SET (信息技术－信息交换用汉字编码字符集 Xinxi Jishu – Xinxi Jiaohuan Yong Hanzi Bianma Zifuji – Jibenji De Kuochong) March 17, 2000, was the publishing date of the Chinese national standard (国家标准 guojia biaozhun) GB 18030-2000 (hereafter: GBK2K). This standard tries to resolve issues resulting from the advent of Unicode, version 3.0. More specific, it attempts the combination of Uni- code's extended character repertoire, namely the Unihan Extension A, with the character cov- erage of earlier Chinese national standards. HISTORY The People’s Republic of China had already expressed her fundamental consent to support the combined efforts of the ISO/IEC and the Unicode Consortium through publishing a Chinese National Standard that was code- and character-compatible with ISO 10646-1/ Unicode 2.1. This standard was named GB 13000.1. Whenever the ISO and the Unicode Consortium changed or revised their “common” standard, GB 13000.1 adopted these changes subsequently. In order to remain compatible with GB 2312, however, which at the time of publishing Unicode/GB 13000.1 was an already existing national standard widely used to represent the Chinese “simplified” characters, the “specification” GBK was created.
    [Show full text]
  • Adaptive Distributed Firewall Using Intrusion Detection Lars Strand
    UNIVERSITY OF OSLO Department of Informatics Adaptive distributed firewall using intrusion detection Lars Strand UniK University Graduate Center University of Oslo lars (at) unik no 1. November 2004 ABSTRACT Conventional firewalls rely on a strict outside/inside topology where the gateway(s) enforce some sort of traffic filtering. Some claims that with the evolving connectivity of the Internet, the tradi- tional firewall has been obsolete. High speed links, dynamic topology, end-to-end encryption, threat from internal users are all issues that must be addressed. Steven M. Bellovin was the first to propose a “distributed firewall” that addresses these shortcomings. In this master thesis, the design and implementation of a “distributed firewall” with an intrusion detection mechanism is presented using Python and a scriptable firewall (IPTables, IPFW, netsh). PREFACE This thesis is written as a part of my master degree in Computer Science at the University of Oslo, Department of Informatics. The thesis is written at the Norwegian Defence Research Establishment (FFI). Scripting has been one of my favourite activities since I first learned it. Combined with the art of Computer Security, which I find fascinating and non-exhaustive, it had to be an explosive combina- tion. My problem next was to find someone to supervise me. This is where Professor Hans Petter Langtangen at Simula Research Laboratory and Geir Hallingstad, researcher at FFI, stepped in. Hans Petter Langtangen is a masterful scripting guru and truly deserves the title “Hacker”. Geir Hallingstad is expert in the field of computer/network security and gave valuable input and support when designing this prototype.
    [Show full text]
  • New Comparative Study Between DES, 3DES and AES Within Nine Factors
    JOURNAL OF COMPUTING, VOLUME 2, ISSUE 3, MARCH 2010, ISSN 2151-9617 152 HTTPS://SITES.GOOGLE.COM/SITE/JOURNALOFCOMPUTING/ New Comparative Study Between DES, 3DES and AES within Nine Factors Hamdan.O.Alanazi, B.B.Zaidan, A.A.Zaidan, Hamid A.Jalab, M.Shabbir and Y. Al-Nabhani ABSTRACT---With the rapid development of various multimedia technologies, more and more multimedia data are generated and transmitted in the medical, also the internet allows for wide distribution of digital media data. It becomes much easier to edit, modify and duplicate digital information .Besides that, digital documents are also easy to copy and distribute, therefore it will be faced by many threats. It is a big security and privacy issue, it become necessary to find appropriate protection because of the significance, accuracy and sensitivity of the information. , which may include some sensitive information which should not be accessed by or can only be partially exposed to the general users. Therefore, security and privacy has become an important. Another problem with digital document and video is that undetectable modifications can be made with very simple and widely available equipment, which put the digital material for evidential purposes under question. Cryptography considers one of the techniques which used to protect the important information. In this paper a three algorithm of multimedia encryption schemes have been proposed in the literature and description. The New Comparative Study between DES, 3DES and AES within Nine Factors achieving an efficiency, flexibility and security, which is a challenge of researchers. Index Terms—Data Encryption Standared, Triple Data Encryption Standared, Advance Encryption Standared.
    [Show full text]
  • The Aes Project Any Lessons For
    THE AES PROJECT: Any Lessons for NC3? THOMAS A. BERSON, ANAGRAM LABORATORIES Technology for Global Security | June 23, 2020 THE AES PROJECT: ANY LESSONS FOR NC3? THOMAS A. BERSON JUNE 23, 2020 I. INTRODUCTION In this report, Tom Berson details how lessons from the Advanced Encryption Standard Competition can aid the development of international NC3 components and even be mirrored in the creation of a CATALINK1 community. Tom Berson is a cryptologist and founder of Anagram Laboratories. Contact: [email protected] This paper was prepared for the Antidotes for Emerging NC3 Technical Vulnerabilities, A Scenarios-Based Workshop held October 21-22, 2019 and convened by The Nautilus Institute for Security and Sustainability, Technology for Global Security, The Stanley Center for Peace and Security, and hosted by The Center for International Security and Cooperation (CISAC) Stanford University. A podcast with Tom Berson and Philip Reiner can be found here. It is published simultaneously here by Technology for Global Security and here by Nautilus Institute and is published under a 4.0 International Creative Commons License the terms of which are found here. Acknowledgments: The workshop was funded by the John D. and Catherine T. MacArthur Foundation. Maureen Jerrett provided copy editing services. Banner image is by Lauren Hostetter of Heyhoss Design II. TECH4GS SPECIAL REPORT BY TOM BERSON THE AES PROJECT: ANY LESSONS FOR NC3? JUNE 23, 2020 1. THE AES PROJECT From 1997 through 2001, the National Institute for Standards and Technology (US) (NIST) ran an open, transparent, international competition to design and select a standard block cipher called the Advanced Encryption Standard (AES)2.
    [Show full text]
  • Data Encryption Standard
    Data Encryption Standard The Data Encryption Standard (DES /ˌdiːˌiːˈɛs, dɛz/) is a Data Encryption Standard symmetric-key algorithm for the encryption of electronic data. Although insecure, it was highly influential in the advancement of modern cryptography. Developed in the early 1970s atIBM and based on an earlier design by Horst Feistel, the algorithm was submitted to the National Bureau of Standards (NBS) following the agency's invitation to propose a candidate for the protection of sensitive, unclassified electronic government data. In 1976, after consultation with theNational Security Agency (NSA), the NBS eventually selected a slightly modified version (strengthened against differential cryptanalysis, but weakened against brute-force attacks), which was published as an official Federal Information Processing Standard (FIPS) for the United States in 1977. The publication of an NSA-approved encryption standard simultaneously resulted in its quick international adoption and widespread academic scrutiny. Controversies arose out of classified The Feistel function (F function) of DES design elements, a relatively short key length of the symmetric-key General block cipher design, and the involvement of the NSA, nourishing Designers IBM suspicions about a backdoor. Today it is known that the S-boxes that had raised those suspicions were in fact designed by the NSA to First 1975 (Federal Register) actually remove a backdoor they secretly knew (differential published (standardized in January 1977) cryptanalysis). However, the NSA also ensured that the key size was Derived Lucifer drastically reduced such that they could break it by brute force from [2] attack. The intense academic scrutiny the algorithm received over Successors Triple DES, G-DES, DES-X, time led to the modern understanding of block ciphers and their LOKI89, ICE cryptanalysis.
    [Show full text]
  • Plain Text & Character Encoding
    Journal of eScience Librarianship Volume 10 Issue 3 Data Curation in Practice Article 12 2021-08-11 Plain Text & Character Encoding: A Primer for Data Curators Seth Erickson Pennsylvania State University Let us know how access to this document benefits ou.y Follow this and additional works at: https://escholarship.umassmed.edu/jeslib Part of the Scholarly Communication Commons, and the Scholarly Publishing Commons Repository Citation Erickson S. Plain Text & Character Encoding: A Primer for Data Curators. Journal of eScience Librarianship 2021;10(3): e1211. https://doi.org/10.7191/jeslib.2021.1211. Retrieved from https://escholarship.umassmed.edu/jeslib/vol10/iss3/12 Creative Commons License This work is licensed under a Creative Commons Attribution 4.0 License. This material is brought to you by eScholarship@UMMS. It has been accepted for inclusion in Journal of eScience Librarianship by an authorized administrator of eScholarship@UMMS. For more information, please contact [email protected]. ISSN 2161-3974 JeSLIB 2021; 10(3): e1211 https://doi.org/10.7191/jeslib.2021.1211 Full-Length Paper Plain Text & Character Encoding: A Primer for Data Curators Seth Erickson The Pennsylvania State University, University Park, PA, USA Abstract Plain text data consists of a sequence of encoded characters or “code points” from a given standard such as the Unicode Standard. Some of the most common file formats for digital data used in eScience (CSV, XML, and JSON, for example) are built atop plain text standards. Plain text representations of digital data are often preferred because plain text formats are relatively stable, and they facilitate reuse and interoperability.
    [Show full text]
  • JFP Reference Manual 5 : Standards, Environments, and Macros
    JFP Reference Manual 5 : Standards, Environments, and Macros Sun Microsystems, Inc. 4150 Network Circle Santa Clara, CA 95054 U.S.A. Part No: 817–0648–10 December 2002 Copyright 2002 Sun Microsystems, Inc. 4150 Network Circle, Santa Clara, CA 95054 U.S.A. All rights reserved. This product or document is protected by copyright and distributed under licenses restricting its use, copying, distribution, and decompilation. No part of this product or document may be reproduced in any form by any means without prior written authorization of Sun and its licensors, if any. Third-party software, including font technology, is copyrighted and licensed from Sun suppliers. Parts of the product may be derived from Berkeley BSD systems, licensed from the University of California. UNIX is a registered trademark in the U.S. and other countries, exclusively licensed through X/Open Company, Ltd. Sun, Sun Microsystems, the Sun logo, docs.sun.com, AnswerBook, AnswerBook2, and Solaris are trademarks, registered trademarks, or service marks of Sun Microsystems, Inc. in the U.S. and other countries. All SPARC trademarks are used under license and are trademarks or registered trademarks of SPARC International, Inc. in the U.S. and other countries. Products bearing SPARC trademarks are based upon an architecture developed by Sun Microsystems, Inc. The OPEN LOOK and Sun™ Graphical User Interface was developed by Sun Microsystems, Inc. for its users and licensees. Sun acknowledges the pioneering efforts of Xerox in researching and developing the concept of visual or graphical user interfaces for the computer industry. Sun holds a non-exclusive license from Xerox to the Xerox Graphical User Interface, which license also covers Sun’s licensees who implement OPEN LOOK GUIs and otherwise comply with Sun’s written license agreements.
    [Show full text]