inssoli.blogg.se - Playfair cipher

PLAYFAIR CIPHER FULL
PLAYFAIR CIPHER SOFTWARE
PLAYFAIR CIPHER FREE

Web development, programming languages, Software testing & others 1.

PLAYFAIR CIPHER FREE

#print (len(letters_added), letters_added)Ĭode to separate same letters.Start Your Free Software Development Course If chr(letter) not in letters_added: # Do not add repeated letters If letter=74: # I/J are in the same position #Add the rest of the alphabet to the matrix

PLAYFAIR CIPHER FULL

See below the full python code for the Playfair cipher.Ĭreating the matrix. So, if we encrypt the message “my secret message” using the key “secret” and the Playfair cipher, we get the ciphertext “LZECRTCSITCVAHBT”. It is encrypted as ‘BT’ following rule 4. It is encrypted as ‘AH’ by following rule 3. It is encrypted as ‘IT’ following rule 4 (same as ‘MY’). Notice that in this case ‘T’ is the last letter in the row, so the next is the first letter in the same row, ‘S’ in this case.

So, ‘S’ is substituted for the next one in the row ‘E’, and ‘E’ is substituted by the next one in the row ‘C’. ‘Y’ is substituted by ‘Z’, because ‘Z’ is in the same row as ‘Y’ and in the same column as ‘M’ (the other letter from the pair). ‘M’ is substituted by ‘L’, because ‘L’ is in the same row as M and in the same column as ‘Y’ (the other letter from the pair). Not in the same column and not in the same row. 5×5 Playfair matrix using the key “secret” So, for easy reference, I’ll repeat the picture of the matrix in this section. Encryption processįirst, we need to have the matrix. Now we are ready to start the encryption. Here, we use a “filler” to separate the two ‘S’.

Let’s divide our plain text into a sequence of pairs of letters.Īs you can see, we have the same letter together in a pair. As per the second rule, we encrypt two letters at a time. Let’s assume we want to encrypt this message (plain text): “my secret message”. Notice after the ‘R’, we add the ‘T’ because the ‘E’ was previously added.įrom there, we complete the matrix with the alphabet, without repeating letters and using ‘I’ and ‘J’ as the same character. 5×5 Playfair matrix using the key “secret”Īs you can see in the picture above, we first add each letter from the secret key (without repeating a letter). If the secret key is “secret”, the matrix should look as in the picture below. Let’s start with an example of how the matrix should look like. Keep reading for you to see examples of each step and rule, and the full Python code for the cipher.

If the two letters are not in the same row and column, then you substitute each letter by the letter in the same row and the column of the second letter.

The next letter of the last in a column is the first letter in that column.

If the two letters fall in the same column of the matrix, you substitute them with the next letter in the column (going down).

The next letter of the last in a row is the first letter in that row.

If the two letters fall in the same row of the matrix, you substitute them with the next letter in the row.

When you get two letters, if they are the same letter, you add a “filler” in the middle.

We encrypt the message using two letters each time.

Letters are placed only once in the matrix. you start filling the matrix with the key, then you use the alphabet. In this matrix, I and J are in the same cell.

Create a 5×5 matrix using the secrete key.

The steps to implement it are as follows: The Playfair cipher is a multiple letter encryption cipher that uses a substitution technique.