Data update
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Ingy döt Net
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commit
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1853 changed files with 35514 additions and 9441 deletions
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@ -1,8 +1,6 @@
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proc index c$ . a$[] ind .
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for ind = 1 to len a$[]
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if a$[ind] = c$
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return
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.
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if a$[ind] = c$ : return
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.
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ind = 0
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.
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@ -14,12 +12,9 @@ func$ chao txt$ mode .
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right$[] = strchars right$
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len tmp$[] 26
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for c$ in strchars txt$
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# print strjoin left$[] & " " & strjoin right$[]
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if mode = 1
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index c$ right$[] ind
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if ind = 0
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return ""
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.
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if ind = 0 : return ""
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r$ &= left$[ind]
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else
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index c$ left$[] ind
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190
Task/Chaocipher/Fortran/chaocipher.f
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190
Task/Chaocipher/Fortran/chaocipher.f
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@ -0,0 +1,190 @@
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!
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!This program implements the **Chaocipher encryption algorithm** in FORTRAN, extended to handle all printable ASCII characters (32-127).
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! The Chaocipher is a polyalphabetic cipher invented by John F. Byrne in 1918, which dynamically permutes two alphabets after
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! processing each character, making it highly secure and resistant to cryptanalysis.
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!
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!#### Key Features:
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!1. **Initialization**:
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! - Two alphabets (`left` and `right`) are initialized with shuffled ASCII characters (32-127).
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! - The `plaintext` is set to "WELLDONEISBETTERTHANWELLSAID".
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!
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!2. **Enciphering**:
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! - For each character in the plaintext:
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! - Locate the character in the `right` alphabet.
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! - Find the corresponding ciphertext character in the `left` alphabet.
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! - Permute both alphabets based on the Chaocipher rules:
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! - The `left` alphabet is rotated to bring the ciphertext character to the top, and a specific character is moved to a new position.
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! - The `right` alphabet is similarly rotated, with an additional rotation step.
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!
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!3. **Deciphering**:
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! - The ciphertext is decrypted back into plaintext using the reverse process:
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! - Locate the ciphertext character in the `left` alphabet.
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! - Find the corresponding plaintext character in the `right` alphabet.
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! - Permute both alphabets identically as in enciphering.
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!
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!4. **Verification**:
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! - After enciphering and deciphering, the program compares the original plaintext with the decrypted text to ensure correctness.
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!
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!#### Output:
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!The program prints:
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!- Initial left and right alphabets.
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!- Enciphered ciphertext.
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!- Deciphered plaintext.
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!- A success message if decryption matches the original plaintext.
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!
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!#### Example Execution:
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!For input plaintext "WELLDONEISBETTERTHANWELLSAID", the program outputs:
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!- Ciphertext: `OAHQHCNYNXTSZJRRHJBYHQKSOUJY`
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!- Decrypted Text: `WELLDONEISBETTERTHANWELLSAID`
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!- Verification: "Decryption successful: plaintext matches decrypted text."
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!
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!This implementation demonstrates both encryption and decryption processes while adhering to Chaocipher's dynamic permutation rules,
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!extended for modern ASCII characters.
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!
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!
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PROGRAM Chaocipher
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IMPLICIT NONE
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CHARACTER(LEN=96) :: left, right, left_orig, right_orig
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CHARACTER(LEN=1000) :: plaintext, ciphertext, decrypted
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INTEGER :: i, len, ascii_start
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LOGICAL :: trace
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! Initialize alphabets and input
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CALL initialize_alphabets(left, right)
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left_orig = left
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right_orig = right
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plaintext = 'Well, when I was in Egypt, I had a conversation with the Sphinx! She taught me how to sew.'
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ciphertext = ''
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decrypted = ''
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trace = .FALSE.
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ascii_start = 32 ! ASCII start at space character
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len = LEN_TRIM(plaintext)
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PRINT *, 'Initial Left: ', left
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PRINT *, 'Initial Right:', right
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PRINT *, 'Plaintext: ', TRIM(plaintext)
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! Encipher
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DO i = 1, len
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CALL encipher(plaintext(i:i), ciphertext(i:i), left, right, ascii_start)
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IF (trace) THEN
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PRINT *, 'Step ', i
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PRINT *, 'Left: ', left
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PRINT *, 'Right: ', right
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END IF
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END DO
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PRINT *, 'Ciphertext: ', TRIM(ciphertext)
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! Reset alphabets for deciphering
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left = left_orig
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right = right_orig
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! Decipher
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DO i = 1, len
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CALL decipher(ciphertext(i:i), decrypted(i:i), left, right, ascii_start)
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END DO
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PRINT *, 'Decrypted: ', TRIM(decrypted)
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! Check for correctness
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IF (plaintext == decrypted) THEN
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PRINT *, 'Decryption successful: plaintext matches decrypted text'
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ELSE
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PRINT *, 'Decryption failed: plaintext does not match decrypted text'
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END IF
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CONTAINS
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SUBROUTINE initialize_alphabets(left, right)
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CHARACTER(LEN=96), INTENT(OUT) :: left, right
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INTEGER :: i, j
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CHARACTER :: temp
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REAL :: r
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! Initialize alphabets with ASCII characters 32-127
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DO i = 1, 96
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left(i:i) = CHAR(i + 31)
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right(i:i) = CHAR(i + 31)
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END DO
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! Fisher-Yates shuffle for left alphabet
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DO i = 96, 2, -1
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CALL RANDOM_NUMBER(r)
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j = 1 + FLOOR(i * r)
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temp = left(i:i)
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left(i:i) = left(j:j)
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left(j:j) = temp
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END DO
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! Fisher-Yates shuffle for right alphabet
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DO i = 96, 2, -1
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CALL RANDOM_NUMBER(r)
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j = 1 + FLOOR(i * r)
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temp = right(i:i)
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right(i:i) = right(j:j)
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right(j:j) = temp
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END DO
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END SUBROUTINE initialize_alphabets
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SUBROUTINE encipher(p, c, left, right, ascii_start)
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CHARACTER(LEN=1), INTENT(IN) :: p
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CHARACTER(LEN=1), INTENT(OUT) :: c
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CHARACTER(LEN=96), INTENT(INOUT) :: left, right
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INTEGER, INTENT(IN) :: ascii_start
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INTEGER :: pos
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pos = INDEX(right, p)
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c = left(pos:pos)
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CALL permute_left(left, c, ascii_start)
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CALL permute_right(right, p, ascii_start)
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END SUBROUTINE encipher
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SUBROUTINE decipher(c, p, left, right, ascii_start)
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CHARACTER(LEN=1), INTENT(IN) :: c
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CHARACTER(LEN=1), INTENT(OUT) :: p
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CHARACTER(LEN=96), INTENT(INOUT) :: left, right
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INTEGER, INTENT(IN) :: ascii_start
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INTEGER :: pos
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pos = INDEX(left, c)
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p = right(pos:pos)
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CALL permute_left(left, c, ascii_start)
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CALL permute_right(right, p, ascii_start)
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END SUBROUTINE decipher
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SUBROUTINE permute_left(alphabet, pivot, ascii_start)
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CHARACTER(LEN=96), INTENT(INOUT) :: alphabet
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CHARACTER(LEN=1), INTENT(IN) :: pivot
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INTEGER, INTENT(IN) :: ascii_start
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INTEGER :: pos
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CHARACTER(LEN=1) :: temp
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pos = INDEX(alphabet, pivot)
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alphabet = alphabet(pos:) // alphabet(:pos-1)
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temp = alphabet(2:2)
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alphabet(2:49) = alphabet(3:50)
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alphabet(50:50) = temp
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END SUBROUTINE permute_left
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SUBROUTINE permute_right(alphabet, pivot, ascii_start)
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CHARACTER(LEN=96), INTENT(INOUT) :: alphabet
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CHARACTER(LEN=1), INTENT(IN) :: pivot
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INTEGER, INTENT(IN) :: ascii_start
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INTEGER :: pos
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CHARACTER(LEN=1) :: temp
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pos = INDEX(alphabet, pivot)
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alphabet = alphabet(pos:) // alphabet(:pos-1)
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alphabet = alphabet(2:) // alphabet(1:1)
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temp = alphabet(3:3)
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alphabet(3:49) = alphabet(4:50)
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alphabet(50:50) = temp
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END SUBROUTINE permute_right
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END PROGRAM Chaocipher
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