1. Progressive Key Cipher encoder
Text : ABCD efghi jklmn
Substitution Cipher Method : vigenere
Key : start
Progressive Key (Shift By) : 1
Alphabet : abcdefghijklmnopqrstuvwxyzSolution:The Progressive Key cipher is a Periodic substitution cipher that uses a keyword which is shift progressively (+1) with each next group, making it more secure. It can be used with any of the Periodic Substitution Cipher: Vigenere, Beaufort, Variant Beaufort, Porta Cipher.
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 |
Each letter is shifted down based on the key letter
| Plaintext | A | B | C | D | | e | f | g | h | i | | j | k | l | m | n |
Text Value
(2) | 0 | 1 | 2 | 3 | | 4 | 5 | 6 | 7 | 8 | | 9 | 10 | 11 | 12 | 13 |
| Key | s | t | a | r | | t | s | t | a | r | | t | s | t | a | r |
Key Value
(4) | 18 | 19 | 0 | 17 | | 19 | 18 | 19 | 0 | 17 | | 19 | 18 | 19 | 0 | 17 |
Progressive Key Shift
(5) | 0 | 0 | 0 | 0 | | 0 | 1 | 1 | 1 | 1 | | 1 | 2 | 2 | 2 | 2 |
Addition
(2) + (4) + (5) Mod 26 | 18 | 20 | 2 | 20 | | 23 | 24 | 26=0 | 8 | 26=0 | | 29=3 | 30=4 | 32=6 | 14 | 32=6 |
| Ciphertext | S | U | C | U | | x | y | a | i | a | | d | e | g | o | g |
So finally
| Plaintext | : ABCD efghi jklmn |
| Key | : start |
| Ciphertext | : SUCU xyaia degog |
2. Progressive Key Cipher encoder
Text : hello world, how are you
Substitution Cipher Method : vigenere
Key : start
Progressive Key (Shift By) : 1
Alphabet : abcdefghijklmnopqrstuvwxyzSolution:The Progressive Key cipher is a Periodic substitution cipher that uses a keyword which is shift progressively (+1) with each next group, making it more secure. It can be used with any of the Periodic Substitution Cipher: Vigenere, Beaufort, Variant Beaufort, Porta Cipher.
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 |
Each letter is shifted down based on the key letter
| Plaintext | h | e | l | l | o | | w | o | r | l | d | , | | h | o | w | | a | r | e | | y | o | u |
Text Value
(2) | 7 | 4 | 11 | 11 | 14 | | 22 | 14 | 17 | 11 | 3 | | | 7 | 14 | 22 | | 0 | 17 | 4 | | 24 | 14 | 20 |
| Key | s | t | a | r | t | | s | t | a | r | t | | | s | t | a | | r | t | s | | t | a | r |
Key Value
(4) | 18 | 19 | 0 | 17 | 19 | | 18 | 19 | 0 | 17 | 19 | | | 18 | 19 | 0 | | 17 | 19 | 18 | | 19 | 0 | 17 |
Progressive Key Shift
(5) | 0 | 0 | 0 | 0 | 0 | | 1 | 1 | 1 | 1 | 1 | | | 2 | 2 | 2 | | 2 | 2 | 3 | | 3 | 3 | 3 |
Addition
(2) + (4) + (5) Mod 26 | 25 | 23 | 11 | 28=2 | 33=7 | | 41=15 | 34=8 | 18 | 29=3 | 23 | | | 27=1 | 35=9 | 24 | | 19 | 38=12 | 25 | | 46=20 | 17 | 40=14 |
| Ciphertext | z | x | l | c | h | | p | i | s | d | x | , | | b | j | y | | t | m | z | | u | r | o |
So finally
| Plaintext | : hello world, how are you |
| Key | : start |
| Ciphertext | : zxlch pisdx, bjy tmz uro |
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