Find the integral part (that is, the part of the number before the decimal point) of the result of Step 3, and append it to the end of List A.Take the sum from Step 2 and divide it by 1 more than the number of cards in Pile C.Take the number in List M that you are currently focussed on, and add that to the product from Step 1.Multiply the last number in List A by 27.Now, focus on the last number in List M and do the following:
Take your key deck, face down, and deal the first 7 cards into a new pile (which we will call Pile C). Elsewhere on your paper, start another list of numbers (which we will call List A) containing just the number 0. Convert the message to a list of 47 numbers (space=0, A=1, B=2, etc.). If your message is shorter than 47 characters, then fill it out with spaces or random padding letters so that it is exactly 47 characters long.
If we use an alphabet of 27 distinct characters (26 letters, plus a space), then we can, in theory, encode in the arrangement of the deck a message of up to 49 characters, since 27 49<54!<27 50.
Here is a C++ program is given to encode a message using Playfair Cipher.If we include the two jokers, there are 54 ! ways to arrange a deck of playing cards. Receiver has the same key and can create the same key table, and then decrypt any messages made using that key. Using these rules, the result of the encryption of ‘hide money’ with the key of ‘tutorials’ would be − QC EF NU MF ZVĭecrypting the Playfair cipher is as simple as doing the same process in reverse. If neither of the preceding two rules are true, form a rectangle with the two letters and take the letters on the horizontal opposite corner of the rectangle.If both letters are in the same row, take the letter to the right of each one (going back to the left if at the farthest right)‘D’ and ‘E’ are in same row, hence take letter to the right of them to replace.If both the letters are in the same column, take the letter below each one (going back to the top if at the bottom)‘H’ and ‘I’ are in same column, hence take letter below them to replace.Let us consider that, we want to encrypt the message “hide money”. If there is an odd number of letters, a Z is added to the last letter. The key table works out to be −įirst, a plaintext message is split into pairs of two letters (digraphs). The rest of the table will be filled with the remaining letters of the alphabet, in natural order. In a key table, the first characters (going left to right) in the table is the phrase, excluding the duplicate letters. The sender and the receiver deicide on a particular key, say ‘tutorials’. If the plaintext contains J, then it is replaced by I. Each of the 25 alphabets must be unique and one letter of the alphabet (usually J) is omitted from the table as we need only 25 alphabets instead of 26. The key table is a 5×5 grid of alphabets that acts as the key for encrypting the plaintext. In playfair cipher, initially a key table is created. In this scheme, pairs of letters are encrypted, instead of single letters as in the case of simple substitution cipher.