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What is the Science of Cryptology? - SCARIO - 07-20-2023
Cryptology is the science of ciphers. It deals with the encryption of various messages and texts according to a certain system, the transmission of these messages to the recipient in a secure environment and the deciphering of the transmitted message.
The science or study of secret writings, coded documents.
Cryptology is a mathematical science, usually based on number theory. It is divided into two different branches. Cryptography is used to encrypt any message, while cryptanalysis is used to decrypt or analyze ciphers.
Cryptology is used in military institutions, in communications between individuals or between private state institutions and in many other fields.
History of Cryptology
Cryptography is derived from the Greek words kriptos, meaning secret, and graphi, meaning writing.
The first cryptologist was an Egyptian scribe who lived 4000 years ago. He created encrypted hieroglyphs to describe the life of his master.
In China, the most prominent civilization of the period, cryptography never developed because it was very difficult to write without a cipher.
Later (5th-6th century BC), cryptography entered the military field due to the need for secrecy in military intelligence. The first military cryptographers were the Spartans.
Some Encryption Techniques
Caesar Encryption
Affine Encryption
Hill Cipher Encryption
Public Key Encryption
Caesar Encryption
Caesar Cipher is created by replacing the letters in a text with the letters that follow it. For example, in a Caesar Cipher with 3 letter skips, ghrhph is written instead of try.
Affine Encryption
With symmetric encryption, 27 different transformations could be made on the text. If we consider the English alphabet, we need to talk about 26-1=25 transformations. This shows that symmetric encryption is not reliable. With the affine method, the symmetric encryption method is slightly more generalized and the security is slightly stronger than the symmetric encryption method. Of course, since this is an example of paper and pencil cryptology, if we think of it in today's terms. It's a very, very weak method. But it is a good example for us to understand the basic logic of cryptology.
For example:
y : (ax+b)MODm
x : Numeric equivalent of letters in plain text m
m: The number of characters of the alphabet used in the plain text
a,b: Our hidden numbers
A-0,B-1 Y-24,Z-25
For example: M O N E Y (according to a=11, b=4 technique)
12 14 13 4 24
If we use the function y=(11x+4)MOD26.
M: y =(11*12+4)MOD26=6 G
O: y =(11*14+4)MOD26=2 C
N: y=(11*13+4)MOD26=17 R
E: y=(11*4+4)MOD26=22 W
Y: y=(11*24+4)MOD26=8 - I
Decryption: For decryption, let's change the function y as follows. X=inverse(a)(y-b)MODm is our decryption function a=11 and b=4, so we can get x=inverse(11)(y-4)MOD26. Inverse(11)MOD26=19 and this is our decryption function;
x=19(y-4)MOD26.
Let's find the numeric value for each character in our ciphertext GCRWI from our table. 6,2,17,22,8.
G : x=19*(6-4)MOD26=12-M
C : x=19*(2-4)MOD26=14 - O
R : x=19*(17-4)MOD26= 13 N
W : x=19*(22-4)MOD26= 4 - E
I : x=19*(8-4)MOD26=24 - Y
In this way we reach our plain text"MONEY"
Hill Cipher Encryption
The Hill encryption method is an example of block cipher. Block cipher can be expressed as follows. Dividing plaintext into contiguous blocks of the same length, encrypting each block into ciphertext blocks, and grouping these ciphertext blocks into ciphertext output. The Hill cipher was invented by Lester Hill and published in 1929.
Public Key Encryption
Public-key encryption is an encryption system that uses different keys for encryption and decryption. Because of this feature of the system, it is also called asymmetric encryption. Each of the communicating parties has a pair of keys. One of the keys that make up these key pairs is the secret key and the other is the public (non-secret) key.
The public key can only be generated by the owner of the secret key and is accessible to everyone. With the public key, information can be encrypted in a way that can only be decrypted by the owner of the secret key, or the authenticity of the numerical signature and identity of the owner of the secret key can be checked.
Working Principle
Cryptology algorithms consist entirely of mathematical functions. For example; in the Caesar cipher, D is used instead of the letter A, E is used instead of the letter B and so on. This means that the algorithm creates the encrypted (cipher) text by replacing each letter it sees with the letter three letters ahead of the corresponding letter in the alphabet. In the early days, for the security of ciphertexts, the encryption and decryption algorithms were kept secret and a secret key was kept
But if we talk about the security of cryptology today, even if the algorithm is known, the text (ciphertext) should not be decrypted. This is where public-key cryptographic algorithms come in. These are a Public Key, which is a key that everyone can see. Secret Key, which is the key that can only be used to obtain the decrypted version of the text.
ripto Machines
Enigma
Russian Fialka (M-125)
U.S. M-209
Swiss NEMA
HC 9
Enigma
It is a cipher machine used by Nazi Germany during World War II to encrypt and decrypt secret messages.
Operating System : Like other Rotor machines, Enigma is an Electro-Mechanical system. Basically, it is a mechanism that generates probability thanks to the rotor mechanism. Similar to a typewriter keyboard, when each keyboard key is pressed, the rotors rotate. The gear mechanism of the rotor was disassembled and reassembled in a different position before each algorithm was programmed. In addition, before each message, the operator arranged the electrical sockets in the lower section differently, making it more difficult to decipher the cipher. Rotor: Used to describe the rotating parts of machines.
Russian Fialka (M-125)
Fielka, codenamed M-125, was a cipher machine developed by the Soviet Union during the Cold War, shortly after World War II.
Like Enigma, it resembles a typewriter keyboard, with rotors spinning each time a key is pressed.
It is used as a message transmitter or duplicator.
It supports Latin and Russian alphabets.
U.S. M-209
It was first designed by the US military for use in World War II and later in the Korean War.
Swiss NEMA
It was produced by the Swiss army during World War II as a replacement for the Enigma machine. It was produced during World War II.
HC 9
Manufactured in 1970 by the Swedish company AB Transvertex.
Quantum Cryptography
The basic principle of quantum cryptography is the use of a single-use key cryptography technique.
Quantum cryptography is less concerned with the transmission of the message than with the reliable exchange between the transmitter and receiver of the key used to encrypt the message and decrypt the encrypted message.
In quantum cryptography, data transmission is not done in classical ways. Data transmission is done with photons instead of electrical signals. Therefore, a fiber optic network is required for the communication channel. . This shows that the quantum cryptography technique cannot actually be used in civilian life. In fact, this technique is currently only used for military purposes on a very limited scale.
Cryptology in Everyday Life
Cryptology is actually everywhere in our daily lives; in the chip bank card, in the car key, in the banking transactions we make over the internet, in wireless networks, in our cell phones, in the copy protection of DVDs, in short, wherever there is valuable information.
Cryptology has become an indispensable part of military communication, command and control and complex weapon systems.
The signatures we sign with a ballpoint pen have been replaced by digital signatures as information shifted from paper to digital media.
With the development of technology, cryptography has started to be seen on store shelves with the use of electronic labels instead of paper labels on products.
Sources:
Enigma machine - Wikipedia
Cryptology - Wikipedia
Bob Lord's Home Page | ilord.com
Fialka - Wikipedia, the free encyclopedia
HC-9 - Wikipedia, the free encyclopedia
RE: What is the Science of Cryptology? - eariel - 11-29-2023
very cool! ty! id love to try this someday saving for later!