I’ve been interested in reading about cryptocurrency and want to learn cryptography but it’s too complicated for me to learn the cryptography especially the algorithms and the other terms that is unfamiliar for me, so I started in the beginning of cryptography which is the ancient times and it’s very interesting and very easy to understand, so I just want to share the things that I discover and it might interest the newbies and other members to read and learn about cryptography.
Cryptography
- The word cryptography is comes from two Greek words, “kryptos” which means hidden and “graphien” which means writing.
- During ancient times cryptography is commonly associated with the word encryption or a method of protecting information through the use of codes or ciphers, or it is a process of converting a normal letters, texts, or numbers into an unintelligible text, figures, images and something that only the writer and receiver should understand, which is commonly used in communications in war during ancient times.
- The process where an ordinary plain text is converted to cipher text is known as encryption while the process of conversion of cipher text to plain text this is known as decryption.
There are many primitive and other techniques that had been used by different civilizations.
1. The Caesar Shift Cipher- This cipher was named in honor of Julius Caesar, this method was effective during the times of war not only because the text was encrypted but the enemies of Rome are also illiterate, and only after the fall of Rome it is decrypted through the analysis of Al-Kindi.
- The concept is the simplest and most widely-known encryption techniques which uses monoalphabetic substitution. It is a substitution cipher with a shift of 3 either to left or right in the alphabet.
Plain: ABCDEFGHIJKLMNOPQRSTUVWXYZ
Cipher using right rotation: DEFGHIJkLMNOPQRSTUVWXYZABC
Cipher using left rotation: XYZABCDEFGHIJKLMNOPQRSTUVW
Example: (With a shift of +3)Plain Text: We're no strangers to love
You know the rules and so do I
Cipher Text:Tb'ob kl pqoxkdbop ql ilsb
Vlr hklt qeb oribp xka pl al F
- There is also another version of it the Augustus Cipher, that is made by his nephew Augustus but with a shift of 1 only.
Example: (With a shift of -1)Plain Text:A full commitment's what I'm thinking of
You wouldn't get this from any other guy
Cipher Text: Z etkk bnllhsldms'r vgzs H'l sghmjhmf ne
Xnt vntkcm's fds sghr eqnl zmx nsgdq ftx
2. Alberti-Vigenere Cipher - This one is also interesting , using a polyalphabetic substitution which the alphabets is embedded within a 2 movable concentric disk that is attached by a pin. The large one is called Stabilis which is fixed or stationary and the Mobilis which is the smaller one and the movable disk. (the characters in mobilis may vary)
Stabilis: ABCDEFGILMNOPQRSTVXZ1234
Mobilis: (random characters)
- Each disk consists of 24 equal cells he Stabilis consist of uppercase letter and 4 numbers while the Mobilis consists of lowercase letters and a special character.
Example:(with Stabilis: ABCDEFGILMNOPQRSTVXZ1234 & Mobilis: c&bmdgpfznjyutoskerlhaiw)Plain Text:I just wanna tell you how Im feeling
Gotta make you understand
Cipher Text:1 munp ufbhs petu ccg fzk Ia cpmunmi
Gzpbf hzjj yzg &laduztsbe
3. Scytale- The scytale was first used in Ancient Greece by the Spartans for secret communication between the war commanders, it is consisted of a stretched leather which has characters written on It seemed like a meaningless sequence of characters but when the stretch of leather is winded around a piece of wood with the correct diameter, an encoded message can be read.
- may consist of: ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz
Example: (7 turns)Plain Text:Never gonna give you up
Never gonna let you down
Cipher Text:Nnyva denoe lova ure we
gugtn ripoy gvN noo eenu
Rendered:| N | e | v | e | r | g | o |
| n | n | a | g | i | v | e |
| y | o | u | u | p | N | e |
| v | e | r | g | o | n | n |
| a | l | e | t | y | o | u |
| d | o | w | n | | | |
4.The Polybius Square- The Polybius Square is an ancient Greek invention, discovered by a scholar named Polybius. For the Greek alphabet of 24 letters, it consisted of a 5 by 5 grid where each square of the grid was filled by a single letter. In the English Alphabet of 26 letters, we have one too many letters. To get round this we combine two letters, traditionally "i" and "j".
- It is also possible to combine other pairs, such as "v" and "u". Another alternative to the Polybius Square for english is to include the digits 0-9, so we have 36 characters. It is also possible to just remove one of the letter such as J,VW,Q and Z or make a mixed square.
- It's either you will use the common 5x5 grid with the 25 Alphabets or you can increase the grid and used mixed square, This is also very simple let's use the figure on the right and let's encrypt the word "Bitcointalk" you just gonna follow the number grid so it should be 2142443143423344111352
[b]Example (Let's use the figure above but without the J)[/b]Plain Text:Never gonna run around and desert you
Never gonna make you cry
Cipher Text:3315511542 2234333311 424533 114234453314 113314 1415431542 44543445
3315511542 2234333311 32112515 543445 134254
5. Pigpen Cipher- The Pigpen Cipher is another example of a substitution cipher, but rather than replacing each letter with another letter, the letters are replaced by symbols.It used mainly by the mason but the origins of the characters that is used is unknown. Most notoriously, it was the cipher of choice for use by the Freemasons, a secret society in the 18th Century. In fact, they used it so much, that it is often referred to as the Freemasons Cipher. However, it was not exclusively used by them, with Union prisoners in Confederate camps using it to communicate in the American Civil War.
Example: (Standard)Plain Text:Never gonna say goodbye
Never gonna tell a lie and hurt you
Cipher Text:
https://economictimes.indiatimes.com/definition/cryptography
https://usa.kaspersky.com/resource-center/definitions/what-is-cryptography
https://www.geeksforgeeks.org/cryptography-and-its-types/
https://www.cs.mcgill.ca/~rwest/wikispeedia/wpcd/wp/c/Caesar_cipher.htm#:~:text=The%20Caesar%20cipher%20is%20named%20after%20Julius%20Caesar%2C%20who%2C%20according,word%20could%20be%20made%20out.
http://www.icits2015.net/ancient-cryptography-history/#:~:text=The%20word%20cryptography%20is%20comes,from%20one%20place%20to%20another.
https://en.wikipedia.org/wiki/Alberti_cipher_disk
https://www.cryptool.org/en/cto-ciphers/scytale
https://www.dcode.fr/scytale-cipher
http://cryptogramma.com/cryptogramma/How_it_works.html
https://interestingengineering.com/11-cryptographic-methods-that-marked-history-from-the-caesar-cipher-to-enigma-code-and-beyond
https://crypto.interactive-maths.com/polybius-square.html