![]() ![]() Well, the original Caesar Cipher algorithm was not supposed to deal with anything other than the 26 letters of the alphabet – either in uppercase or lowercase. What about the numbers? What about the special characters and the punctuation? Now that we’ve seen how we can encode and decode capital letters of the English alphabet using Caesar Cipher, it begs an important question – What about the other characters? Let’s write the code for the above procedure: shift = 3 # defining the shift count Else, if the character is not capital, keep it unchanged.Replace the current encrypted letter by this new character (which will also be an uppercase letter).Perform the negative shift using the modulo operation.If the character is an uppercase letter:.Iterate over each character in the encrypted text:.Let us look at the step-by-step implementation of the decryption process, which will be more or less the reverse of the encryption: If any value becomes negative after subtraction, the modulo operator will take care of that, and it will wrap it around. The meaning of the notations remains the same as in the previous formula. Let’s now check out the same for the decryption process. Now that we’ve figured out the encryption for plain text capital letters using Ceaser Cipher let’s look at how we will decrypt the ciphertext into plain text.Įarlier, we looked at the mathematic formulation of the encryption process. # since character is not uppercase, leave it as it is # check if character is an uppercase letter Let us now look at the code: shift = 3 # defining the shift count Else, If the character is not upper-case, keep it with no change.Replace the current capital letter by this new character.Find the character at the new position.Perform the positive shift using the modulo operation.Calculate the position/index of the character in the 0-25 range.Iterate over each character of the plain text:.Define the shift value i.e., the number of positions we want to shift from each character.Print("Unicode 360 represents", character_360) Print("Unicode 100 represents", character_100) Print("Unicode 65 represents", character_65) Let’s first look at a few examples: character_65 = chr(65) The chr() method accepts a number representing the Unicode of a character and returns the actual character corresponding to the numeric code. ![]() Just like how we could convert a character into its numeric Unicode using ord() method, we do the inverse i.e., find the character represented by a number using chr() method. ![]() It accepts a single character and returns the number representing its Unicode. You can use the ord() method to convert a character to its numeric representation in Unicode. We’ll look at two built-in functions in Python that are used to find the Unicode representation of a character and vice-versa. are also represented in memory by their Unicode. Note that the special characters like space ” “, tabs “\t”, newlines “\n”, etc. That means ‘A’ will still be represented using the number 65 in Unicode. Similarly, lowercase characters’ representation begins with the number 97.Īs the need to incorporate more symbols and characters of other languages arose, the 8 bit was not sufficient, so a new standard – Unicode – was adopted, which represents all the characters used in the world using 16 bits.ĪSCII is a subset of Unicode, so the ASCII encoding of characters remains the same in Unicode. The computer doesn’t understand any of our English language’s alphabet or other characters by itself.Įach of these characters is represented in computer memory using a number called ASCII code (or its extension – the Unicode) of the character, which is an 8-bit number and encodes almost all the English language’s characters, digits, and punctuations.įor instance, the uppercase ‘A’ is represented by the number 65, ‘B’ by 66, and so on. It is important to realize that the alphabet as we know them, is stored differently in a computer’s memory. Before we dive into defining the functions for the encryption and decryption process of Caesar Cipher in Python, we’ll first look at two important functions that we’ll use extensively during the process – chr() and ord(). ![]()
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