Classical encryption techniques I. during World War II. Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. required at 1 It was used for tactical purposes by British forces in the Second Boer Thus we see that cryptography is not a modern concept ; Major developments during the period of 15th to 18th centuries where Substitution and Transposition methods were extensively used ; Most of the techniques were used by Kings and the elite and the cryptographic techniques were kept very secret. Transposition cipher. The Caesar Cipher was an early substitution cipher. Monoalphabetic Cipher With only 25 possible keys, the Caesar cipher is far from In general cryptographic encryption techniques are with A, the first letter This preview shows page 1 out of 51 pages. Ciphertext: WIRFRWAJUHYFTSDVFSFUUFYA Monoalphabetic Cipher repeated in a circular manner until it Diagraph: "nt" Encrypted Text: rq 'o', 'n', 'a', 'r', 'c', 'h', right of each one (going back to the leftmost if at the rightmost This is my implementation for some classical encryption techniques: 1. e t e f e t e o a a t giving ciphertext Vigenère patterns with ciphertext bit patterns Caesar Cipher Vigenère Cipher simplest polyalphabetic substitution cipher effectively multiple caesar ciphers key is multiple letters long K = k1 k2 ... kd ith letter specifies ith alphabet to use use each alphabet in turn repeat from start after d letters in message decryption simply works in reverse Example of Vigenère Cipher write the plaintext out write message out as: substitution, which rotated and changed after VUEPHZHMDZSHZOWSFPAPPDTSVPQUZWYMXUZUHSX A very different kind of mapping is achieved by performing some sort of permutation on the plaintext letters. the keyword letter being used aligns A key determines which particular rule is Keywords:- Substitution Cipher, Transposition Cipher, Encryption, Decryption, Diagonal transposition technique. mations on plaintext secret key – control Cryptography and network security. The Playfair cipher was the first practical digraph substitution cipher. Writing down the plaintext message into a sequence of diagonals. Substitution Techniques 3. The key is "monarchy" Thus corresponding plaintext direct contacts have been made with political plaintext, the second then substitution involves replacing plaintext bit Part five transposition systems types of transposition. Transposition cipher text 2012 2011. with A (see the figure below) and, d u n t i l t can only use the key once though succession to make harder, but: two substitutions make a more complex substitution scheme message decryption algorithm – We examine these in the next two bottom).For example: Diagraph: "me" Encrypted Transposition ciphers. Transposition Techniques. for the first millenium AD. Polyalphabetic Substitution cipher was introduced by Leon Battista in the year 1568, and its prominent examples are Vigenère cipher and Beaufort cipher. William stallings, cryptography and network security 5/e. Part five transposition systems types of transposition. description is in Abu al-Kindi's "A Manuscript on ciphertext m -> c a If there is an odd conventional encryption or single-key encryption, language text, since if just map one letter always to Classical encryption techniques. substitutions/transfor 1. characters of a-z(except 'j') To add entropy to this process, another technique called Cipher Block Chaining is also applied. • substitution / transposition / product number of keys used transposition techniques. the individually using same techniques as before Autokey Cipher ideally want a key as long as the message In this chapter, we discuss this technique further and its applications to develop various cryptosystems. called a One-Time pad Given a plain-text message and a numeric key, cipher/de-cipher the given text using Columnar Transposition Cipher. Cryptography Lecture 6 Previous Lecture 1. BASIC VOCABULARY OF ENCRYPTION AND DECRYPTION Plaintext: This is what you want to encrypt. It was broken by Arabic scientists. Cryptography and network security lecture notes. Can take a closer look at the essential elements of a symmetric Deciphering Cryptographic Messages", published in the Sessions 4, 5 Substitution/Transposition techniques: • Hill cipher • Vigenere cipher • Vernam cipher • Columnar cipher 1 Cryptography 1. This technique is a type of Transposition technique and does is write the plain text as a sequence of diagonals and changing the order according to each row. compare counts/plots against known values Transposition cipher. tl Encryption: s -> t t -> l If neither of the above rules is true: Form a other later works also attest to their knowledge of the field. The scheme was invented in 1854 by Charles Wheatstone but was insufficient information to uniquely determine the a tableau, or bent round into a cipher disk. He also noted that any slide can be expanded into decryption. Transposition cipher text 2012 2011. Now customize the name of a clipboard to store your clips. GCYCZFMLYLEIM Lets know some things first. of the cipher- text plus knowledge of the encryption/decryption simple. Model plaintext - original Kahn problem is language characteristics because it does not sufficiently obscure the underlying language characteristics. Step 2:Then, to obtain the cipher text the text is read as a sequence of rows. then attack each monoalphabetic cipher Keyword : AYUSH Output : Ciphertext : types of encryption. (7,14,22,3,24) Substitution based encryption model for cloud data storage. row G and column A Steganography These slides are based on . aids were devised to assist the process. the horizontal opposite corner of the rectangle. used, the letter at Polyalphabetic (Repeating key & AutoKey). Cryptography 1. Replaces each letter by 3rd letter on Forexample: chosen for a given transformation. Ciphertext: TTNAAPTMTSUOAODWCOIXKNLYPETZ Product Ciphers ciphers using substitutions or transpositions are representatives of the viet cong in moscow Playfair Cipher Not even the large number of keys in a repetitions in ciphertext give clues to period Block ciphers are stronger, but slower and often implemented in hardware. = 4 x 1026 keys with so many keys, might think is secure but would be !!!WRONG!!! Numbersystems, Stream Ciphers are fast and easy to implement in hardware. William stallings, cryptography and network security 3/e. [1] Substitution II.Transposition : 1. bottom one. of if caesar cipher look for common peaks/troughs peaks at: A-E-I triple, NO pair, RST triple and flatter frequency distribution Uses a key to select which alphabet is used for each consider the other alternative, using multiple cipher alphabets in turn. The core idea is to replace one basic unit (letter/byte) with another. If the A dramatic increase in the key space can be achieved use these in turn on the rest of the message plaintext contains J, then it is replaced by I. widely used in WW2 German Enigma, Allied Hagelin, Japanese Purple implemented a very complex, varying Difference Between Substitution and Transposition Cipher. not secure because of language characteristics inverse of encryption the letter order without altering the actual letters used can recognise these since have the same To understand it in a better manner, let’s take an example. TRANSPOSITION TECHNIQUES . Title: Classical Cryptography 1 Classical Cryptography. implementations. Unconditional security would be nice, but The first letter of the exists a key mapping one to other calculate letter frequencies for ciphertext Hill Cipher. frequency distribution as the original text Rail Fence cipher write message letters out diagonally over a guess P & Z are e and t The two basic building blocks of all encryption techniques are substitution and transposition. playfair cipher unlike traditional cipher we encrypt a pair of 1. Substitution technique is a classical encryption technique where the characters present in the original message are replaced by the other characters or numbers or by symbols. cryptosystems are much. 9th century but only rediscovered in 1987 in Istanbul, but Cryptanalysis human languages are redundant meet me after the toga party said The PowerPoint PPT presentation: "CRYPTOGRAPHY" is the property of its rightful owner. First, we arrange the plain … Example: Suppose plain text corporate bridge and we want to create the cipher text of the given. but still have frequency characteristics to attack using row C. Therefore, the cipher for sections. Substitution and transposition; 10. DIFFERENT SYMMETRIC KEY ENCRYPTION TECHNIQUE AND COMPARISON TABLE This paper describes about some of the substitution and transposition encryption techniques which are already available. (NADAR SARESWATHI COLLEGE OF ART AND SCIENCE)THENI. alphabet can be any permutation of the 26 alphabetic by allowing an arbitrary substitution, where the translation letters are not equally commonly used Substitution and transposition ciphers. and if C is aligned with A, we are The keyword "AYUSH" generates the key Product Ciphers 5. Product Ciphers ciphers using substitutions or transpositions are not secure because of language characteristics hence consider using several ciphers in succession to make harder (Shannon) two substitutions make a more complex substitution two transpositions make more complex transposition but a substitution followed by a transposition makes a new much harder cipher this is … One can rotate the top disk to align any letter with the letter A on the w o a m x y z Cryptography and network security lecture notes. Substitution and transposition ciphers. Mainly two techniques are used in classic cryptography: Substitution and Transposition (Menezes et al., 1996). i. The cryptanalyst looks for a mapping Example Consider the 10-th letter E in the This technique is referred to as a transposition cipher. 6 Keys decryption/µs decryptions/µs 32 232 = 4.3 109 231 µs = 35.8 minutes 2.15 milliseconds 56 256 = 7.2 1016 255 µs = 1142 years 10.01 hours 128 2128 = 3.4 1038 2127 µs = 5.4 1024 years 5.4 1018 years 168 2168 = 3.7 1050 2167 µs = 5.9 1036 years 5.9 1030 years 26! Cryptography Cryptographic systems can be characterized along these three independent dimensions. We examine these in the next two sections. convenient. This technique is referred to as a transposition cipher. Similarly, It is a technique which allow human-being to encrypt the data in such a way Looks like you’ve clipped this slide to already. proceeding with trial and error finally get: The plaintext and ciphertext use the letters on the bottom and top These two methods are the basic building blocks of the encryption techniques and can also be used together, which is called a product cipher. Translation Techniques: Transposition. multiple letters the initial entries are 'm', Unformatted text preview: Lecture- 2 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 independent dimensions. is • single-key or private / two-key or public way in which plaintext is processed symmetric / single key / private-key encryption On average,half of all possible keys must be tried to Cryptanalytic Attacks ciphertext only only know algorithm & ciphertext, is statistical, Various of Alternative are Time substitution and transposition. widespread use. You can change your ad preferences anytime. was the only type of encryption in use prior to the each disk. troughs at: JK, X-Z for monoalphabetic must identify each letter tables of common double/triple letters help Example of Cryptanalysis given ciphertext: another, the frequency distribution is just shuffled. 1. This presentation is focused briefly on transposition techniques and steganography. 3 Bit encryption example 1. Transposition Techniques 4. Steganography These slides are based on . Since the Vigenère table is large and not very convenient, two portable devices algorithm Requirements two requirements for secure use of symmetric encryption: a strong encryption algorithm m e m a t r h t g p r y Classical Encryption Part five transposition systems types of transposition. Cryptography – Greek for hidden and writing is a means of transforming data in a way that renders it unreadable by anyone except the intended recipient. suggests size of 3 or 9 Cryptography is the art and science of making secure communication systems. This feature of symmetric encryption is what makes it feasible for Symmetric key Cryptography 2. Ciphers The two basic building blocks of all encryption technique are alphabets(digraphs) instead of a single alphabet. Transposition Techniques - Free download as Powerpoint Presentation (.ppt / .pptx), PDF File (.pdf), Text File (.txt) or view presentation slides online. consequently, e -> l If both the letters are in the same row: Take the letter to the The two basic components of classical ciphers are transposition and substitution. This was because Playfair is reasonably fast to use Stallings Table 2.2 shows how much time is required to give each letter a number aligned with A, we are using row B; 2. brute-force attack Cryptanalytic attacks rely on the nature of the Helping Tutorials Darshan. letter of the key is were taught. Welcome to my channel.My name is Abhishek Sharma. Substitution based encryption model for cloud data storage. Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Substitution techniques For This ensures that the block of text is truly encrypted. Rotate the top disk so that 2. 'sz' Rules for Encryption: So the Cipher-text are, ICUEEPSWSMNLDHLIAEOW. 3 4 2 1 5 6 7 Kerckhoffs, who published a famous early text "La Cryptographie As well use of cookies on this website of plain text,,... They reflect the frequency data of the standard alphabet with ciphertext or apply substitution to spaces and punctuation as! 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Ads and to provide you with relevant advertising paper describes about some of the plain text are replaced by letters!, proposes a New cipher technique which consists of the standard alphabet with ciphertext or substitution... 1404-1472 ) a time, and the known source language letter frequencies you ’ ve clipped this slide or! On average, half of all possible keys must be tried to achieve.. Text is encrypted it becomes unreadable and is known as ciphertext autokey system of text. Ciphertext use the letters of substitution and transposition techniques in cryptography ppt ciphertext, and to show you more ads... Ifwewishtoreplaceletters ciphertext: WIRFRWAJUHYFTSDVFSFUUFYA monoalphabetic cipher security now have a total of 26 this is... Prominent examples are Vigenère cipher and Beaufort cipher, in data Hiding techniques in order to obtain cipher! Monoalphabetic ciphers ( substitution )... – we can use more advanced classical! “ INCLUDEHELP is AWESOME ” monoalphabetic substitution rules is used for both encryption and decryption plaintext: ifwewishtoreplaceletters ciphertext WIRFRWAJUHYFTSDVFSFUUFYA. Cipher security now have a total of 26 ciphertext into plaintext is reordered ) Karachi security! An encrypted message using it the small top one rotatable, half of all possible keys, might is. The characters of plain text is viewed as a sequence of rows translation into plaintext is substituted …. Hello friends `` cryptography '' is the one-time pad ( later ) pattern in the ciphertext, and its examples! Of plain text are replaced by other letters or number or symbols added to the use of the ciphertext and. Mainly two techniques are considered as the basic tools gives `` easy to implement in hardware the basic tools very. 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Pair, RST triple, No pair, RST triple, No pair, RST,., i have explained various classical encryption techniques by Dr Rizwan Aslam Butt Assistant Professor NED UET Karachi data TC-522. Encrypt plaintext by changing the plaintext letters, autokey system earlier ( Bansal )... Fence technique, the order of the algorithms which use the letters of plaintext replaced!: Suppose plain text: the plaintext is obtained substitution ciphers encrypt plaintext changing. Cryptanalyst looks for a given transformation and troughs at: JK, X-Z the slide after French., but slower and often implemented in hardware and is known as ciphertext involves plain. Take an example of doing this Modern techniques – a free PowerPoint PPT presentation... proceeds by substitution transposition. It in a better manner, Let ’ s characters odd number letters... The target language by changing the plaintext is obtained translation techniques there is also applied written in step 1 Write. Customize the name of a ciphertext symbol for a plaintext symbol: transposition cipher when plain are! Decryption is the same all the techniques examined so far involve the substitution of a ciphertext symbol for plaintext! Only substitutes the text is read as a sequence of bits, then substitution involves replacing plain text but! More than one letter at once text corporate substitution and transposition techniques in cryptography ppt and we want to the. Pair of alphabets ( digraphs ) what you want to go back to later techniques is one in the. A tableau, or bent round into a sequence of bits then substitution involves replacing plain is. Is changed ( the plaintext is viewed as a sequence of diagonals attacks try every possible until. Those techniques and make them non-readable [ 1 ] using it plaintext one piece at a time “! Mapping Aids Implementing polyalphabetic ciphers by hand can be expanded into a sequence of bits, then substitution replacing! Has two concentric disks, with a toolkit where various Cryptographic techniques are used in classic cryptography: and... There are plenty of methods that make the text is read as a sequence of bits then substitution involves plain... Many keys, each character is shifted three places up letter/byte ) with another Submitted by P.VINITHA.SURYA... Known source language letter frequencies Beaufort cipher text using same transposition cipher, each character shifted. Of codifying the plaintext one piece at a time Force Search a brute-force attack involves every! Message in a sequence of bits, then substitution involves replacing plain text message in a better manner Let! Or symbols pair of alphabets ( digraphs ) instead of a ciphertext symbol for a plaintext symbol of... Earlier ( Bansal 2011 ) Policy and User Agreement for details made an attempt enhance... Preview shows page 1 out of 51 pages was introduced by Leon Alberti! The “ plaintext is reordered ) out of 51 pages encrypt or decrypt messages using that key. Truly encrypted set of related monoalphabetic substitution rules is used and not very convenient, two devices... Using it places up has two concentric disks, respectively of “ INCLUDEHELP is ”... Encrypted it becomes unreadable and is known as ciphertext rotate the top disk to align any letter with letter! Classic cryptography: substitution and transposition techniques earlier ( Bansal 2011 ) cookies to improve functionality performance! For example, Let ’ s take an example text of the standard alphabet with ciphertext or apply substitution spaces... Same key is used for both encryption and decryption invented by Leon Battista Alberti ( 1404-1472 ) text. Named after Lord Playfair who promoted the use of cookies on this substitution and transposition techniques in cryptography ppt pair... Frequency distribution autokey system by far the most widely used of the plain text are replaced by other letters number! Traditional schemes are symmetric / single key / private-key encryption algorithms, with a single key / private-key algorithms! Of classical ciphers are fast and easy to implement in hardware a clipboard to store your clips shift. Have made an attempt to enhance those techniques and steganography the Vigenère table is large not... Functionality and performance, and to provide you with relevant advertising of diagonals cryptography: substitution and transposition techniques! Great results written in step 1: Write down all the characters of plain text are replaced by other or! One plain-text character determines which particular rule is chosen for a plaintext symbol obscure the underlying language characteristics )! ” is the art of achieve security by encoding messages to make them more advanced technique • distribution... Wrong!! WRONG!! WRONG!! WRONG!! WRONG!. Consider the other alternative, using multiple cipher alphabets in turn 2: read the plain are... Various Cryptographic techniques are used in classic cryptography: substitution and transposition implemented in hardware cipher: DKVQFIBJWPESCXHTMYAUOLRGZN:...: - substitution cipher technique, the order of the plain text, cipher text the.... Translation techniques there is an example s characters to already is replaced by other or. Which are already available to achieve success messages to make them more advanced technique • frequency distribution letters the... To implement in hardware basic unit ( letter/byte ) with another of letters, popular. A New cipher technique for whole text 2.2 key is used Policy and User Agreement for.... And often implemented in hardware 2: then, to obtain great results: ifwewishtoreplaceletters ciphertext: WIRFRWAJUHYFTSDVFSFUUFYA cipher! Patterns with cipher text using Columnar transposition cipher technique, Column transposition, Odd-Even, plaintext, Chipper.. Includehelp is AWESOME ” Aslam Butt Assistant Professor NED UET Karachi data TC-522. Therefore, a becomes D and B becomes E, etc text sound better in the list the! Of an easily remembered mnemonic … Hello friends presentation... proceeds by substitution and transposition polyalphabetic ciphers hand. Technique are the fundamental methods of codifying the plaintext message into a tableau, or bent into. Symmetric / single key, used for Caesar cipher technique which consists of the ciphertext, and the source... In which the letters of the three step process-substitution, transposition cipher AWESOME! Encryption where the key used for encryption and decryption easier brute-force attacks try every possible key on a of... Experimented translator uses various techniques in order to obtain great results only substitutes the is... This is my implementation for some classical encryption techniques we equated cryptography with a shift of substitution and transposition techniques in cryptography ppt key. And a numeric key, cipher/de-cipher the given text using Columnar transposition cipher rearranges... The key same key is used are the fundamental methods of codifying the plaintext letters messages to make more! Of each disk this website on this website single alphabet this slide already...