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Chronology of Cryptology 1MJ Sanada, 2MJ Segal, 1Kh © 2019 JETIR June 2019, Volume 6, Issue 6 www.jetir.org (ISSN-2349-5162) Chronology of Cryptology 1MJ Sanada, 2MJ Segal, 1Kh. Chanchanbi and 3Kh. Manglem Singh MIT Manipur1, MTU Manipur2, NIT Manipur3 Abstract This paper gives a brief overview of cryptology including cryptography, cryptanalysis and hashing function from the ancient era till present days. All the cryptography techniques and their corresponding cryptanalysis are described briefly. The latest cryptography techniques such as RSA algorithm and elliptic curve cryptography are also described. Keywords:- Cryptology, Cryptography, Cryptanalysis, Hashing function, RSA, ECC. 1. Introduction Cryptology consists of cryptography and cryptanalysis. Cryptography is the science of secret writing message by transforming in an unintelligible form such that it looks like a garbage to the undesired recipient and only legitimate one can read the object by transforming it back into the original form using the secret key she or he possesses. It is a reversible process that transforms the original message known as plaintext into another form known as ciphertext by using a process known as encryption algorithm with a secret key, which is known to the sender and recipient, and it is retransformed into original form by using the reverse process known as decryption algorithm and the key that is with the recipient. Cryptology Cryptography Cryptanalysis Classical Modern Asymmetric Symmetric Hash Substitution Transposition Cipher Cipher Function Monoalp Polyalp Block Stream ECC RSA MD5 SHA habetic habetict Cipherr Cipher ic AES DES RC4 A5 Figure 1 Chronology of Cryptology Cryptanalysis, on the other hand is the art and science of breaking cryptography. Chronology of cryptology can be based on different era of the development of the cryptography, such as ancient world, era between the ancient world and present days including World War I and World War II, and present days. Figure 1 shows the chronology of cryptology. JETIR1907107 Journal of Emerging Technologies and Innovative Research (JETIR) www.jetir.org 762 © 2019 JETIR June 2019, Volume 6, Issue 6 www.jetir.org (ISSN-2349-5162) 2. Ancient era 2.1 Ancient Greek Cryptography Scytale is an ancient form of encryption commonly used by ancient Greeks [1]. It is a form of transposition cipher where letters are re-arranged in the messages prior to being deciphered by the recipient. It was developed around 404 BC by Spartan generals so that generals could exchange message. Figure 2 shows the scytale. Figure 2 Scytale. Another Ancient Greek Cryptography is Polybius cryptography [2]. It is shown in Figure 3. 1 2 3 4 5 1 A B C D E 2 F G H I&J K 3 L M N O P 4 Q R S T U 5 V W X Y Z Figure 3 Polybius cryptography. For example Message T H I S I S E A S Y T O B R E A K Cipher 44 23 24 43 24 43 15 11 43 54 44 34 12 42 15 11 25 The ciphertext is represented by row number and column number in the square. It was intended for long distance signaling. To send the first letter T, one would hold 4 torches in the right hand and 4 in left hand. 2.2 Ancient Rome Cryptography Caesar cipher was used by the emperor, Julius Caesar during his reign from 49 BC to 44 BC. Each letter was replaced by the third letter to follow it alphabetically. Caesar was able to hide his objectives from regional enemies. It is shown in Figure 4. a b c d e f g h j j k l m n o p q r s t u v w x y z D E F G H J J K L M N O P Q R S T U V W X Y Z A B C Figure 4 Caesar cipher. For example Message becomes ET TU BRUTE? Cipher HW WX EUXWH? If there is a sufficiently large ciphertext, it can be decrypted by comparing the frequency of letters in the cipher text against the frequency of letters in standard English. If the frequency of the letter in the cipher text is same as the frequency of letters, the algorithm might have been based on substitution cipher such as Caesar cipher for which there are 26 possible shifts. One technique may try 26 possible shifts and check which of these resulted in readable English text. JETIR1907107 Journal of Emerging Technologies and Innovative Research (JETIR) www.jetir.org 763 © 2019 JETIR June 2019, Volume 6, Issue 6 www.jetir.org (ISSN-2349-5162) 2.3 Ancient Egypt Cryptography It started around 2000 BC in Egypt. It was mainly hieroglyphic substitution, changing one symbol by less known one. Most of the pictures can stand for the object they represent. Hieroglyphics can be pictures of living creatures, objects used in daily life or symbols. Some are easy to identify, some confusing and some impossible! If you look at the alphabet chart in Figure 5 [3], you can easily spot the foot, the hand, the lion and the owl. These are not thought to be serious attempts as secret communication, however, but rather to have been attempts at mystery, intrigue, or even amusement for literate onlookers. Figure 5 Hieroglyphic substitution. Figure 6 Cuneiform. 2.4 Ancient Mesopotamia Cryptography Cryptography of ancient Mesopotamia used Cuneiform tablets that contains the formula for making pottery glazes even during 4000 BC [4]. In cuneiform, a carefully cut writing implement known as a stylus was pressed into soft clay to produce wedge-like impressions that represent word-signs (pictographs) and, later, phonograms or `word-concepts' (closer to a modern-day understanding of a `word'). Figure 6 shows cuneiform. 2.5 Ancient China Cryptography China did not develop any meaningful cryptography. However most messages were memorized and sent in person to be delivered orally. Their techniques include written message on paper concealed with wax or concealed elsewhere on the body or swallowed. For example, the ancient Chinese wrote messages on fine silk, which then was scrunched into a tiny ball and covered in wax and swallowed by a messenger. 2.6 Ancient Indian Cryptography Kama-sutra, a text written in the 4 AD by the Brahmin scholar Vatsyayana used substitution cipher [5]. The kamasutra generated list of alphabet with no duplicate as shown in Figure 7. Then divide by 2 row. Find for each letter of message text in table and choose the opposite of the letter. JETIR1907107 Journal of Emerging Technologies and Innovative Research (JETIR) www.jetir.org 764 © 2019 JETIR June 2019, Volume 6, Issue 6 www.jetir.org (ISSN-2349-5162) Key = G H A J R I O B E S Q C L F V Z T Y K M X W N U D P G H A J R I O B E S Q C L – 1st row F V Z T Y K M X W N U D P – 2nd row Figure 7 Ancient India cryptography. For example Message – NIT Manipur Cipher - skj ozsklqy 2.7 Ancient Hebrew Cryptography In the Bible, a Hebrew ciphering method is used in 600 BC [6]. The last letter is replaced by the first letter and vice versa. Figure 8 shows the algorithm. a b c d e f g h j j k l m n o p q r s t u v w x y z Z Y X W V U T S R Q P O N M L K J I H G F E D C B A Figure 8 Ancient Hebrew cryptography. For example Message – HELLO Cipher - SVOOL 2.8 Ancient Arab Cryptography The Arabs were the first people to understand cryptanalysis [7]. They realised the rarest letters in Arabic and the most common letters: the letters 'a' and 'l' are the most common in Arabic, whereas the letter 'j' appears only a tenth as frequency. This leads to the first great breakthrough in cryptanalysis, namely frequency analysis. The earliest known description comes from the 9 AD scientist Abū-Yūsuf Ya’qūb ibn Ishāq al- Kindī. Letters and corresponding relative frequencies are shown in Table 1 for English alphabet. The technique is to write down all ciphertext letters and find the frequencies of all letters. 3. Era between the ancient and present days 3.1 Substitution Cipher 3.1.1 Affine Cipher Affine cipher is the generalization of Caesar cipher. Its form is 퐶 = 푎푀 + 푏 (푚표푑 26), for letter M, where (푎, 푏) is key 퐾, and 퐾 = (0, 푏) is not allowed. 퐾 = (1,3) gives a Caesar cipher [8]. If two letters in the message and their corresponding ciphertext letters are known, the key can be found easily and affine cipher can be broken. Table 1 Sample English Statistics Letter Relative frequency (%) Letter Relative frequency (%) A 8.2 N 6.7 B 1.5 O 7.5 C 2.8 P 1.9 D 4.3 Q 0.1 E 12.7 R 6.0 F 2.2 S 6.3 G 2.0 T 9.0 H 6.1 U 2.8 I 7.0 V 1.0 J 0.2 W 2.4 K 0.8 X 0.2 L 4.0 Y 2.0 M 2.4 Z 0.1 JETIR1907107 Journal of Emerging Technologies and Innovative Research (JETIR) www.jetir.org 765 © 2019 JETIR June 2019, Volume 6, Issue 6 www.jetir.org (ISSN-2349-5162) 3.1.2 Alberti Cipher Leon Battista Alberti (1404 - 1472) invented Alberti cipher in 1467 that consists of two metal disks as shown in Figure 9 [9]. Inner disk contains alphabets that may be rotated with respect to the outer disk to form substitution ciphertext.
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