Caesar Shift Crossword Puzzle

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Across
  1. 2. Process of converting plaintext to ciphertext
  2. 4. Reverse the encryption process
  3. 5. The original unencoded message
  4. 8. Number of positions to move each letter
  5. 9. Another name for the shifting technique used
Down
  1. 1. Type of cipher that replaces letters with other letters
  2. 3. The 26 letters used in English encoding
  3. 6. The number that determines how far to shift
  4. 7. First name of the Roman general who used this cipher