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Home > College Algebra > Ciphers > Running Key Cipher (encoder / decoder) example
21. Running Key Cipher (encoder / decoder) example ( Enter your problem )
( Enter your problem )
  1. Examples
 		Other related methods
  1. A1Z26 Cipher (Letter to number Cipher)
  2. ADFGVX Cipher
  3. ADFGX Cipher
  4. Affine Cipher
  5. Atbash Cipher
  6. Autokey Cipher / Autoclave Cipher
  7. Bacon Cipher
  8. Beaufort Cipher
  9. Bifid Cipher
  10. Caesar Cipher
  11. Chaocipher
  12. Columnar transposition Cipher
  13. Nihilist Cipher
  14. Polybius Square Cipher
  15. Rail fence Cipher
  16. ROT-5 Cipher
  17. ROT-13 Cipher
  18. ROT-18 Cipher
  19. ROT-47 Cipher
  20. ROT-N Cipher
  21. Running Key Cipher
  22. Substitution Cipher
  23. Tap code Cipher
  24. Trifid Cipher
  25. Trithemius Cipher
  26. Vigenere Cipher
20. ROT-N Cipher
(Previous method)		22. Substitution Cipher
(Next method)

1. Examples


1. Running Key Cipher encoder

Text : ABCD efghi
Key : bcdefghijklm
Alphabet : abcdefghijklmnopqrstuvwxyz

Solution:
The Running key cipher is a polyalphabetic substitution cipher that encrypts a message using a long non-repeating keyword

Alphabet = abcdefghijklmnopqrstuvwxyz

Letterabcdefghijklmnopqrstuvwxyz
Number012345678910111213141516171819202122232425

Each letter is shifted down based on the key letter
PlaintextABCD efghi
Text Value
(2)		012345678
Keybcde fghij
Key Value
(4)		123456789
Addition
(2) + (4) Mod 26		1357911131517
CiphertextBDFH jlnpr

Plaintext : ABCD efghi
Key : bcdefghijklm
Ciphertext : BDFH jlnpr
2. Running Key Cipher encoder

Text : hello world
Key : bcdefghijklm
Alphabet : abcdefghijklmnopqrstuvwxyz

Solution:
The Running key cipher is a polyalphabetic substitution cipher that encrypts a message using a long non-repeating keyword

Alphabet = abcdefghijklmnopqrstuvwxyz

Letterabcdefghijklmnopqrstuvwxyz
Number012345678910111213141516171819202122232425

Each letter is shifted down based on the key letter
Plaintexthello world
Text Value
(2)		74111114221417113
Keybcdef ghijk
Key Value
(4)		12345678910
Addition
(2) + (4) Mod 26		8614151928=221252013
Ciphertextigopt cvzun

Plaintext : hello world
Key : bcdefghijklm
Ciphertext : igopt cvzun



This material is intended as a summary. Use your textbook for detail explanation.
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20. ROT-N Cipher
(Previous method)		22. Substitution Cipher
(Next method)


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