On the Subject of Odd One Out
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Super Duper Semaphore Or, As We Like to Call It
Super Duper Semaphore Or, as we like to call it ... Flag Texting! Hello Lieutenants ... You can have a whole lot of fun with just a couple of hand flags. Even if you don’t have actual flags, you can make your own using items found around your home, like tea towels, or even two smelly old socks tied to some sticks! As long as you’re having fun ... be inventive. What’s it all about? Well, believe it or not, a great way for ships near (in range of) each other or ships wanting to communicate to the land is to use ‘Flag Semaphore’. It’s a bit like sending a text message ... but with your arms. It has been used for hundreds of years on both land and sea (from the sea, red and yellow flags are used). The word semaphore is Greek for ‘Sign-bearer’ Here’s how it works… Each letter of the alphabet has its own arm position (plus a few extras that we will cover in later ranks). Once you can remember these, you can send loads of hidden messages to your friends and family. Check these out ... ABCDEFG HIJKLM NOPQR STUVWX YZ How cool is that? To send a message the ‘sender’ gets the attention of the ‘receiver’ by waving their arms (and flags) by their side in an up and down motion (imagine flapping your arms like a bird). Don’t worry if you make mistakes or the receiver translates your signals into silly words - we’ve had lots of fun practicing this, and it will take time to become a Super Signaller! Are you ready to send your message? One letter at a time? Remember to pause between each letter and a bit longer between words to accurately get your message through. -
CS 241 Data Organization Ciphers
CS 241 Data Organization Ciphers March 22, 2018 Cipher • In cryptography, a cipher (or cypher) is an algorithm for performing encryption or decryption. • When using a cipher, the original information is known as plaintext, and the encrypted form as ciphertext. • The encrypting procedure of the cipher usually depends on a piece of auxiliary information, called a key. • A key must be selected before using a cipher to encrypt a message. • Without knowledge of the key, it should be difficult, if not nearly impossible, to decrypt the resulting ciphertext into readable plaintext. Substitution Cipher • In cryptography, a substitution cipher is a method of encryption by which units of plaintext are replaced with ciphertext according to a regular system. • Example: case insensitive substitution cipher using a shifted alphabet with keyword "zebras": • Plaintext alphabet: ABCDEFGHIJKLMNOPQRSTUVWXYZ • Ciphertext alphabet: ZEBRASCDFGHIJKLMNOPQTUVWXY flee at once. we are discovered! Enciphers to SIAA ZQ LKBA. VA ZOA RFPBLUAOAR! Other substitution ciphers Caesar cipher Shift alphabet by fixed amount. (Caesar apparently used 3.) ROT13 Replace letters with those 13 away. Used to hide spoilers on newsgroups. pigpen cipher Replace letters with symbols. Substitution Cipher: Encipher Example OENp(ENTE#X@EN#zNp(ENCL]pEnN7p-pE;8N]LN} dnEdNp#Nz#duN-Nu#dENXEdzE9pNCL]#L8NE;p-b @];(N0G;p]9E8N]L;GdENn#uE;p]9Nld-L/G]@]p _8NXd#|]nENz#dNp(EN9#uu#LNnEzEL;E8NXd#u# pENp(ENQELEd-@NOE@z-dE8N-LnN;E9GdENp(EN^ @E;;]LQ;N#zN<]bEdp_Np#N#Gd;E@|E;N-LnN#Gd NT#;pEd]p_8Nn#N#dn-]LN-LnNE;p-b@];(Np(]; N5#L;p]pGp]#LNz#dNp(ENCL]pEnN7p-pE;N#zN) uEd]9-D Breaking a Substitution Cipher In English, • The most common character is the space: \ ". -
Tap Code 1 2 3 4 5 1 a B C D E 2 F G H I J 3 L M N O P 4 Q R S T U 5
Solution to Kryptos 2: Challenge 1 The audio files indicate that the prisoners are communicating with each other by “tapping”. There are two distinct tapping sounds which indicate the two prisoners are exchanging some sort of information back and forth. Furthermore, unlike Morse Code, each audio file is made up of pairs of taps which leads one to believe that each pair of taps corresponds to a word or letter. The longest tapping sequence is five, so if one assumes that each tap-pair corresponds to a pair of integers between 1 and 5, then this code could encipher 25 items – most likely letters. At this point, one could try a frequency analysis to help identify which pairs of integers correspond to which letters. Alternatively, a little research might yield the “tap code” (see e.g. Wikipedia) which has been used by prisoners of war in various conflicts throughout history, most recently Vietnam. It is based on the Polybius square, some of which have slightly different arrangements of the 26 letters placed into 25 cells. Challenge 1 was based on the following key found on Wikipedia: Tap code 1 2 3 4 5 1 A B C D E 2 F G H I J 3 L M N O P 4 Q R S T U 5 V W X Y Z The tap code table This has all letters except “K”, so “C” is used instead. The letter “X” is used to separate sentences. The first audio file begins with the following tap-pairs: (2,4), (4,3), (1,3), (3,4), (5,1), (1,5), (4,2),… which yields the following plaintext: i, s, c, o, v, e, r, … By adding in the likely punctuation, the complete conversation can be decoded: PLAINTEXT Prisoner 1: Is cover intact? Prisoner 2: Yes. -
Eie312 Communications Principles
EIE312 COMMUNICATIONS PRINCIPLES Outline: Principles of communications: 1. An elementary account of the types of transmission (Analogue signal transmission and digital signal transmission). Block diagram of a communication system. 2. Brief Historical development on communications: a. Telegraph b. Telephony c. Radio d. Satellite e. Data f. Optical and mobile communications g. Facsimile 3. The frequency Spectrum 4. Signals and vectors, orthogonal functions. 5. Fourier series, Fourier integral, signal spectrum, convolution, power and energy correlation. 6. Modulation, reasons for modulation, types of modulation. 7. Amplitude modulation systems: a. Comparison of amplitude modulation systems. b. Methods of generating and detecting AM, DBS and SSB signals. c. Vestigial sideband d. Frequency mixing and multiplexing, frequency division multiplexing e. Applications of AM systems. 8. Frequency modulation systems: 1 a. Instantaneous frequency, frequency deviation, modulation index, Bessel coefficients, significant sideband criteria b. Bandwidth of a sinusoidally modulated FM signal, power of an FM signal, direct and indirect FM generation, c. Various methods of FM demodulation, discriminator, phase-lock loop, limiter, pre- emphasis and de-emphasis, Stereophonic FM broadcasting 9. Noise waveforms and characteristics. Thermal noise, shot noise, noise figure and noise temperature. Cascade network, experimental determination of noise figure. Effects of noise on AM and FM systems. 10. Block diagram of a superheterodyne AM radio receiver, AM broadcast mixer, local oscillator design, intermodulation interference, adjacent channel interference, ganging, tracking error, intermediate frequency, automatic gain control (AGC), delay AGC, diode detector, volume control. 11. FM broadcast band and specification, Image frequency, block diagram of a FM radio receiver, limiter and ratio detectors, automatic frequency control, squelch circuit, FM mono and FM stereo receivers. -
Grade 7/8 Math Circles Cryptography What Is Cryptography? Caesar Cipher
Faculty of Mathematics Centre for Education in Waterloo, Ontario N2L 3G1 Mathematics and Computing Grade 7/8 Math Circles Winter 2015 - March 24/25 Cryptography What is Cryptography? Cryptography is the study of protecting, coding, storing and transmitting information and messages so that only those who are intended to may read it. In other words, it is the study of secret messages and codes. Encryption is the conversion of messages to the secret code, called ciphertext. In order to read the information normally, one must decrypt the ciphertext, converting it back into plaintext. Today, we will look at some different types of cryptography that are used. Caesar Cipher The first ciphertext that we will look at is Caesar Cipher. This ciphertext was used by Julius Caesar so that his messages could not be read by his enemies if intercepted. The cipher is used by shifting the alphabet. We use a number which will be the amount we shift the alphabet to get the ciphertext. The following is an example of a shift of 5: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z V W X Y Z A B C D E F G H I J K L M N O P Q R S T U Notice how each letter in the ciphertext is moved over 5 letters from the plaintext. So, the word \MATHEMATICS" in ciphertext would appear as \HVOCZHVODXN". Decrypt the message \NUWJ HKRAO YDKYKHWPA" using Caesar Cipher with a shift of 4. -
Chloé Quenum + Adrian Dan: Minimally Invasive 26.02 --- 26.3.2015
Chloé Quenum + Adrian Dan: Minimally Invasive 26.02 --- 26.3.2015 opening / february 26, 2015 / 19:00h Galeria Nicodim Bucharest Cantacuzino Palace Nr. 141, Victoria Street 010 071 Bucharest, Sector 1 Romania The drudgery of creative professionalism. A mix---up in the wash. Your best black shirt now looks like the skin of an old bronze statue, weepy with corrosion. There’s that jacket that makes you look interesting. Some tchotchkes on the desk. The obsolete deftness with which you made emoticons, now quaint as shorthand, or flag semaphore. Hopping from capital---to---capital, the same sleek wooden angles backed by a different iconic skyline at the best hotel in . Thumbing through pictures of an old crush on your phone, some old notes from a previous “project” tucked away until they are of use again. Maybe it’s time for a new shelf, one that angles just so.... Of all the shelves being built in the world, surely there is one that is just right. Surely someone has thought of you. There’s always time to rearrange the furniture; the fettered sticks that make up letters and words; the rows of images that don’t make a story. Adrian Dan (born 1985 in Constanta, Romania) works and lives in Paris. Adrian graduated as MA (honors) in 2011 at Ecole Nationale Superieure des Beaux Arts (ENSBA) in Paris. He had solo exhibitions in Paris and Bucharest, participated in group exhibitions in Brussels, Bucharest and Paris and is currently one of six researchers in residence at Marfa, Texas. Chloe Quenum (born 1983 in Paris, France) works and lives in Paris. -
Grade 6 Math Circles Cryptography Solutions Atbash Cipher Caesar Cipher
Faculty of Mathematics Centre for Education in Waterloo, Ontario N2L 3G1 Mathematics and Computing Grade 6 Math Circles November 5/6 2019 Cryptography Solutions Hello World Khoor Zruog Hello Zruog Khoor Khoor Zruog World 1. Person A encrypts plaintext 2. Person B receives ciphertext 3. Person B decrypts ciphertext back into ciphertext into plaintext Atbash Cipher Examples 1. Encrypt \Math Circles" using the Atbash cipher. Nzgs Xrixovh 2. Decrypt \ORLM PRMT" using the Atbash cipher. LION KING Caesar Cipher Examples: Encrypt or decrypt the following messages using the shift number given in parentheses: a) Welcome to Math Circles! (5) Bjqhtrj yt Rfym Hnwhqjx! plaintext A B C D E F G H I J K L M N O P Q R S T U V W X Y Z ciphertext F G H I J K L M N O P Q R S T U V W X Y Z A B C D E 1 b) Ljw hxd anjm cqrb? (9) Can you read this? plaintext A B C D E F G H I J K L M N O P Q R S T U V W X Y Z ciphertext J K L M N O P Q R S T U V W X Y Z A B C D E F G H I c) What if I did a Caesar Shift of 26 units on \Welcome to Math Circles!"? A Caesar shift of 26 would be shifting by the length of the alphabet. For example I would be shifting A 26 letters to the right. -
Flags and Banners
Flags and Banners A Wikipedia Compilation by Michael A. Linton Contents 1 Flag 1 1.1 History ................................................. 2 1.2 National flags ............................................. 4 1.2.1 Civil flags ........................................... 8 1.2.2 War flags ........................................... 8 1.2.3 International flags ....................................... 8 1.3 At sea ................................................. 8 1.4 Shapes and designs .......................................... 9 1.4.1 Vertical flags ......................................... 12 1.5 Religious flags ............................................. 13 1.6 Linguistic flags ............................................. 13 1.7 In sports ................................................ 16 1.8 Diplomatic flags ............................................ 18 1.9 In politics ............................................... 18 1.10 Vehicle flags .............................................. 18 1.11 Swimming flags ............................................ 19 1.12 Railway flags .............................................. 20 1.13 Flagpoles ............................................... 21 1.13.1 Record heights ........................................ 21 1.13.2 Design ............................................. 21 1.14 Hoisting the flag ............................................ 21 1.15 Flags and communication ....................................... 21 1.16 Flapping ................................................ 23 1.17 See also ............................................... -
Index of Linguistic Items
Cambridge University Press 978-1-108-42359-5 — The Cambridge Encyclopedia of the English Language 3rd Edition David Crystal Index More Information VI INDEX OF LINGUISTIC ITEMS A auto 322, 330, 493 classist 189 -eau(x) 213 auto- 138 c’mon 79 -ectomy 210 a indefinite article 234–5, 350 aye 346 co- 138 -ed form 208, 210, 216, 223, 224, 237, short vs long 327, 345, 371 cockroach 149 346, 350 verb particle 367 B colour 179 -ed vs t (verb ending) 216, 331, 493 a- 138, 335 contra- 138 -ee 210, 220 -a noun singular 212 /b-/, /-b/ (sound symbolism) 263 could 224 -een 358 noun plural 212 B/b 271, 280 counter- 138 -eer 210, 220 -a- (linking vowel) 139 babbling 483 cowboy 148 eh 319 A/a 271, 280 back of 331 crime 176 eh? 230, 362 AA (abbreviations) 131 bad 211 curate’s egg 437 elder/eldest 211 -able 210, 223 barely 230 cyber- 452 elfstedentocht 383 ableism 189 bastard 263 Elizabeth 158 -acea 210 be 224, 233, 237, 243, 367 D -elle 160 a crapella 498 inflected 21, 363 ’em 287 -ae (plural) 213 regional variation 342 /d-/, /-d/ (sound symbolism) 263 en- 138 after (aspectual) 358, 363 be- 138 D/d 271, 280–1 encyclop(a)edia 497 -age 210, 220 be about to 236 da 367 encyclopediathon 143 ageist 189 been 367 danfo 495 -ene 160 agri- 139 be going to 96, 236 dare 224 -en form 21, 210, 212, -aholic 139 Berks 97 data 213 346, 461 -aid 143, 191 best 211 daviely 352 Englexit 124 ain’t 319, 498 be to 236 De- 160 -er adjective base ending 211 aitch 359 better 211 de- 138 familiarity marker 141, 210 -al 210, 220, 223 between you and I 206, 215 demi- 138 noun ending -
Loads of Codes – Cryptography Activities for the Classroom
Loads of Codes – Cryptography Activities for the Classroom Paul Kelley Anoka High School Anoka, Minnesota In the next 90 minutes, we’ll look at cryptosystems: Caesar cipher St. Cyr cipher Tie-ins with algebra Frequency distribution Vigenere cipher Cryptosystem – an algorithm (or series of algorithms) needed to implement encryption and decryption. For our purposes, the words encrypt and encipher will be used interchangeably, as will decrypt and decipher. The idea behind all this is that you want some message to get somewhere in a secure fashion, without being intercepted by “the bad guys.” Code – a substitution at the level of words or phrases Cipher – a substitution at the level of letters or symbols However, I think “Loads of Codes” sounds much cooler than “Loads of Ciphers.” Blackmail = King = Today = Capture = Prince = Tonight = Protect = Minister = Tomorrow = Capture King Tomorrow Plaintext: the letter before encryption Ciphertext: the letter after encryption Rail Fence Cipher – an example of a “transposition cipher,” one which doesn’t change any letters when enciphered. Example: Encipher “DO NOT DELAY IN ESCAPING,” using a rail fence cipher. You would send: DNTEAIECPN OODLYNSAIG Null cipher – not the entire message is meaningful. My aunt is not supposed to read every epistle tonight. BXMT SSESSBW POE ILTWQS RIA QBTNMAAD OPMNIKQT RMI MNDLJ ALNN BRIGH PIG ORHD LLTYQ BXMT SSESSBW POE ILTWQS RIA QBTNMAAD OPMNIKQT RMI MNDLJ ALNN BRIGH PIG ORHD LLTYQ Anagram – use the letters of one word, phrase or sentence to form a different one. Example: “Meet behind the castle” becomes “These belched a mitten.” Substitution cipher – one in which the letters change during encryption. -
CODE SCHOOL: TOP SECRET COMMUNICATIONS DURING WWII Codes and Ciphers a Code Is a Word Or Message That Is Replaced with an Agreed Code Word Or Symbol
CODE SCHOOL: TOP SECRET COMMUNICATIONS DURING WWII Codes and Ciphers A code is a word or message that is replaced with an agreed code word or symbol. A cipher is when each letter in an alphabet is replaced with another letter, number, picture, or other symbol. Ciphers always have key that is shared among those sending and receiving the message. A coded message would be like saying, “The eagle has landed!”, while a cipher may look like this: 8-5-12-12-15. In the cipher, each letter of the alphabet has been replaced by its corresponding number (A = 1). Do you know the message? Communications during Wartime Navajo Code Talkers Humans figured out how to send secret One incredible example of transmitting secret messages a long time ago. The Greeks used messages was through the US’s use of the something we now call the Caesar cipher (the Navajo language. More than 400 Navajo alphabet is shifted so each letter is replaced by Indians served as code talkers, communicating a different one), while Spartans used a device secret messages for the U.S. Marines. These called a scytale (where a message was written Navajo servicemen were specially trained to on a piece of paper and would be read using a use their own language to communicate during special rod). battles throughout the Pacific campaign. The Navajo code used their own Navajo words to stand for English words. For example, the English word “air” was translated into the Navajo word for air. If an English word did not exist in the Navajo language, they would use Navajo words to symbolize the English word— Skytale submarine became besh-lo, meaning iron fish. -
Grade 7 and 8 Math Circles Cryptography Introduction
Faculty of Mathematics Centre for Education in Waterloo, Ontario N2L 3G1 Mathematics and Computing Grade 7 and 8 Math Circles March 19th/20th/21st Cryptography Introduction Before we begin, it's important to look at some terminology that is important to what we will be learning about. Plaintext: The message or information a sender wishes to share with a specific person. It is very easy to read and must be somehow hidden from those that are not intended to see it. Encryption: The process of the plaintext in such a way that only authorized parties can clearly read it. Ciphertext: The text created by plaintext. It looks like gibberish and is very hard to read. Cipher: A of transforming a message to conceal its meaning. Decryption: The opposite of . It is the process of turning ciphertext back into the readable plaintext. Substitution Cipher The earliest evidence of cryptography have been found in Mesopotamian, Egyptian, Chinese, and Indian writings, but it was the Hebrew scholars of 600 to 500 BCE that began to use simple substitution ciphers. In a substitution cipher the alphabet is rewritten in some other order to represent the the substitution. Caesar Ciphers The Caesar cipher is the simplest and most famous substitution cipher. It was first used by the famous Roman general Julius Caesar, who developed it to protect important military messages. 1 To produce a Caesar cipher simply shift the alphabet some units to the right. Julius Caesar's original cipher was created by shifting the alphabet three units to the right, as shown below. plaintext A B C D E F G H I J K L M ciphertext X Y Z A B C D E F G H I J plaintext N O P Q R S T U V W X Y Z ciphertext K L M N O P Q R S T U V W When encrypting a message, match every letter in the plaintext with the corresponding ciphertext letter beneath it.