How to Encrypt Messages with an Alphabetic One Time Pad

Step-by-Step Guide

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   Step 1: Create and maintain a one-time pad.

   Your message cannot be longer than the length of the one-time pad.
   
   You may want to establish abbreviations and other shorthand with your partner to ensure you can communicate effectively. , Use the method on which your pad is based. ,,,,, A=0, B=1, C=2, and continues through Z=25.
   
   The letter I would be 8 and D would be
   3.
   
   It is traditional to subtract the numbers when encrypting and add the numbers when decrypting.
   
   You must agree upon which convention to use with your partner.
   
   In this case, we will use the traditional method; we would be subtracting 8 from 3, which would be
   5. , This is known has modular arithmetic. ,,, To prevent an eavesdropper attempting to figure out the message using word length, it is often stylized into groups: ,
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   Step 2: Write your message.

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   Step 3: Create the cipher text.

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   Step 4: Assume that your message is I LOVE LIFEGUIDE

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   Step 5: For ease

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   Step 6: you can use a Vigenere square or you can do the encryption by hand.

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   Step 7: Assume our one-time pad key is: FLZYZ DLHSK LMKLI TNDXN HOEPV BNCJW

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   Step 8: The first set of characters (FLZYZ) are used to start your message so that the receiver can verify that you are both using the same key.

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   Step 9: To do the encryption by hand

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    Step 10: take the clear-text letter (in this case

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    Step 11: the letter I) and figure out it's numerical value.

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    Step 12: If the result is negative

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    Step 13: add 26.

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    Step 14: Here is the overall result:

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    Step 15: The unused portions of the key are left out of the encoded message.

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    Step 16: Send the resulting message.

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    Step 17: FLZYZ FAHDU LAAYZ VR

Detailed Guide

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