1. Beaufort Cipher encoder
Text : ABCD efghi
Key : bcd
Alphabet : abcdefghijklmnopqrstuvwxyz
Mode : Key-TextSolution:The Beaufort cipher is a polyalphabetic substitution cipher, where the plaintext is subtracted from the keyword to encrypt a message
Alphabet = abcdefghijklmnopqrstuvwxyz
| Letter | a | b | c | d | e | f | g | h | i | j | k | l | m | n | o | p | q | r | s | t | u | v | w | x | y | z |
| Number | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 |
| Plaintext | A | B | C | D | | e | f | g | h | i |
Plaintext Value
(2) | 0 | 1 | 2 | 3 | | 4 | 5 | 6 | 7 | 8 |
| Key | b | c | d | b | | c | d | b | c | d |
Key Value
(4) | 1 | 2 | 3 | 1 | | 2 | 3 | 1 | 2 | 3 |
Key Value - Plaintext Value
(4) - (2) Mod 26 | 1 | 1 | 1 | -2+26
=24 | | -2+26
=24 | -2+26
=24 | -5+26
=21 | -5+26
=21 | -5+26
=21 |
| Ciphertext | B | B | B | Y | | y | y | v | v | v |
| Plaintext | : ABCD efghi |
| Key | : bcd |
| Ciphertext | : BBBY yyvvv |
2. Beaufort Cipher encoder
Text : hello world
Key : bcd
Alphabet : abcdefghijklmnopqrstuvwxyz
Mode : Key-TextSolution:The Beaufort cipher is a polyalphabetic substitution cipher, where the plaintext is subtracted from the keyword to encrypt a message
Alphabet = abcdefghijklmnopqrstuvwxyz
| Letter | a | b | c | d | e | f | g | h | i | j | k | l | m | n | o | p | q | r | s | t | u | v | w | x | y | z |
| Number | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 |
| Plaintext | h | e | l | l | o | | w | o | r | l | d |
Plaintext Value
(2) | 7 | 4 | 11 | 11 | 14 | | 22 | 14 | 17 | 11 | 3 |
| Key | b | c | d | b | c | | d | b | c | d | b |
Key Value
(4) | 1 | 2 | 3 | 1 | 2 | | 3 | 1 | 2 | 3 | 1 |
Key Value - Plaintext Value
(4) - (2) Mod 26 | -6+26
=20 | -2+26
=24 | -8+26
=18 | -10+26
=16 | -12+26
=14 | | -19+26
=7 | -13+26
=13 | -15+26
=11 | -8+26
=18 | -2+26
=24 |
| Ciphertext | u | y | s | q | o | | h | n | l | s | y |
| Plaintext | : hello world |
| Key | : bcd |
| Ciphertext | : uysqo hnlsy |
This material is intended as a summary. Use your textbook for detail explanation.
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