Classical Cryptography

readme.md

This is classical cruyptography series with Octave, i hope this working on matlab too :)

classicalcryptography.m

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columnarTranspositionDecode.m

% This code running on octave :)
% author : hyhilman (hilman nihri)(hy.hilmann@gmail.com)

function plain = columnarTranspositionDecode(key, cipher)
  if(size(key)(2) != size(unique(key))(2))
    printf('Kunci yang digunakan tidak unique\n');
    result = '';
    return;
  else
    removedKeyFromOrderedColumnarMatrices = num2cell(reshape(cipher, [], size(key)(2)));
    removedKeyFromOrderedColumnarMatricesString = strjoin(removedKeyFromOrderedColumnarMatrices', '');
    size = size(removedKeyFromOrderedColumnarMatricesString)(2) / size(key)(2);
    orderedColumnarMatrices = stringToMatricesWithHeader(sort(key), removedKeyFromOrderedColumnarMatricesString);
    columnarMatrices = cell(size+1,[]);
    for i = key
      firstrow = cell2mat(orderedColumnarMatrices(1,:));
      c = orderedColumnarMatrices(:,firstrow==i);
      columnarMatrices = [columnarMatrices,c];
    end
    columnarMatrices([1],:) = [];
    plain = strjoin(columnarMatrices','');
    return;
  end
end

columnarTranspositionEncode.m

% This code running on octave :)
% author : hyhilman (hilman nihri)(hy.hilmann@gmail.com)

function cipher = columnarTranspositionEncode(key, plain)
  key = key(~isspace(key));
  plain = plain(~isspace(plain));
  if(sizeof(key) != sizeof(unique(key)))
    printf('Kunci yang digunakan tidak unique\n');
    result = '';
    return;
  else
    columnarMatrix = stringToMatricesWithHeader(key, plain);
    orderedColumnarMatrix = sortrows(columnarMatrix',1)';
    removedKeyFromOrderedColumnarMatrix = orderedColumnarMatrix;
    removedKeyFromOrderedColumnarMatrix([1],:) = [];
    cipher = strjoin(removedKeyFromOrderedColumnarMatrix,'');
    return;
  end
end

createArrayOfChar.m

% This code running on octave :)
% author : hyhilman (hilman nihri)(hy.hilmann@gmail.com)

function nChar = createArrayOfChar(row, col)
  char = cell(row, col);
  char(:) = {'x'};
  nChar = strjoin(char,'');
  return;
end

doubleColumnarTranpositionDecode.m

% This code running on octave :)
% author : hyhilman (hilman nihri)(hy.hilmann@gmail.com)

function plain = doubleColumnarTranpositionDecode(key1, key2, cipher)
  if(size(key1)(2) != size(unique(key1))(2) && size(key2)(2) != size(unique(key2))(2))
    printf('Kunci yang digunakan tidak unique\n');
    result = '';
    return;
  else
    cipherTextFirst = columnarTranspositionDecode(key2, cipher);
    plain = columnarTranspositionDecode(key1, cipherTextFirst);
    return;
  end
end

doubleColumnarTranpositionEncode.m

% This code running on octave :)
% author : hyhilman (hilman nihri)(hy.hilmann@gmail.com)

function cipher = doubleColumnarTranpositionEncode(key1, key2, plain)
  if(size(key1)(2) != size(unique(key1))(2) && size(key2)(2) != size(unique(key2))(2))
    printf('Kunci yang digunakan tidak unique\n');
    result = '';
    return;
  else
    cipherTextFirst = columnarTranspositionEncode(key1, plain);
    cipher = columnarTranspositionEncode(key2, cipherTextFirst);
    return;
  end
end

generatePolybiusMatrices.m

% This code running on octave :)
% author : hyhilman(hilman nihri)(hy.hilmann@gmail.com)

function matrices = generatePolybiusMatrices(key = '')
  stringOfMatrices = strcat(upper(key), upper('abcdefghiklmnopqrstuvwxyz'));
  [~,sortedUniqueStringOfMatrices] = unique(stringOfMatrices, 'first');
  polybiusText = stringOfMatrices(sort(sortedUniqueStringOfMatrices));
  matrices = reshape(polybiusText, 5, [])';
  return;
end

generateVigenereMatrices.m

% This code running on octave :)
% author : hyhilman (hilman nihri)(hy.hilmann@gmail.com)

function vigenereMatrix = generateVigenereMatrices()
  aToZ = [1:1:26];
  vigenereMatrixOfAscii = mod((aToZ + aToZ') - 2, 26) + 65;
  vigenereMatrix = char(vigenereMatrixOfAscii);
  return;
end

nihilistDecode.m

% This code running on octave :)
% author : hyhilman (hilman nihri)(hy.hilmann@gmail.com)

function plain = nihilistDecode(key, cipher)
  cipherOfKey = polybiusEncode(key, key);
  charOfKey = 0;
  cipher1 = [];
  for i = cipher
    charOfKey = mod(charOfKey, size(key))(2) + 1;
    cipher1 = [cipher1, i - cipherOfKey(charOfKey)];
  end
  plain = polybiusDecode(cipher1, key);
  return;
end

nihilistEncode.m

% This code running on octave :)
% author : hyhilman (hilman nihri)(hy.hilmann@gmail.com)

function cipher = nihilistEncode(key, plain)
  cipherTextFirst = polybiusEncode(plain, key);
  cipherOfKey = polybiusEncode(key, key);
  charOfKey = 0;
  cipher = [];
  for i = cipherTextFirst
    charOfKey = mod(charOfKey, size(key))(2) + 1;
    cipher = [cipher, i + cipherOfKey(charOfKey)];
  end
  return;
end

polybiusDecode.m

% This code running on octave :)
% author : hyhilman (hilman nihri)(hy.hilmann@gmail.com)

function plain = polybiusDecode(cipher, key='')
  polybiusMatrices = generatePolybiusMatrices(key);
  plain = [];
  for i = cipher
    strOfIndex = num2str(i);
    row = strOfIndex(1);
    col = strOfIndex(2);
    c = polybiusMatrices(str2num(row),str2num(col));
    plain = [plain, c];
  end
  return;
end

polybiusEncode.m

% This code running on octave :)
% author : hyhilman(hilman nihri)(hy.hilmann@gmail.com)

function cipher = polybiusEncode(plain, key = '')
  plainWithoutSpace = upper(plain(~isspace(plain)));
  polybiusMatrices = generatePolybiusMatrices(key);
  cipher = [];
  for i = plainWithoutSpace
    if(i=='j') 
      i = 'i';
    end
    [row, col] = find(polybiusMatrices==i);
    c = [num2str(row), num2str(col)];
    cipher = [cipher, str2num(c)];
  end
  return;
end

stringToMatricesWithHeader.m

% This code running on octave :)
% author : hyhilman (hilman nihri)(hy.hilmann@gmail.com)

function matrixWithHeader = stringToMatricesWithHeader(firstrow, plain)
  col = size(firstrow)(2);
  extraColToPlain = col - mod(size(plain)(2), col);
  if(extraColToPlain != col) 
    plain = strcat(plain,createArrayOfChar(1,extraColToPlain));
  end
  charArray = num2cell(strcat(firstrow, plain));
  matrixWithHeader = reshape(charArray, size(firstrow)(2), [])';
  return;
end

vigenereDecode.m

% This code running on octave :)
% author : hyhilman (hilman nihri)(hy.hilmann@gmail.com)

function plain = vigenereDecode(key, cipher)
  length = size(key);
  key = upper(key);
  vigenereMatrix = generateVigenereMatrices();
  indexOfVigenereMatrix = [1:1:26];
  indexOfKey = 0;
  plain = [];
  for c = cipher
    indexOfKey = mod(indexOfKey, length(2)) + 1;
    row = double(indexOfVigenereMatrix+ 64) == key(indexOfKey);
    cipherRow = vigenereMatrix(row,:);
    col = indexOfVigenereMatrix(cipherRow == c);
    plain = [plain, char(col+64)];
  end
  return;
end

vigenereEncode.m

% This code running on octave :)
% author : hyhilman (hilman nihri)(hy.hilmann@gmail.com)

function cipher = vigenereEncode(key, plain)
  key = upper(key);
  plain = upper(plain);
  length = size(key);
  vigenereMatrix = generateVigenereMatrices();
  indexOfVigenereMatrix = [1:1:26];
  indexOfKey = 0;
  cipher = [];
  for c = plain
    indexOfKey = mod(indexOfKey, length(2)) + 1;
    row = double(indexOfVigenereMatrix+ 64) == key(indexOfKey);
    col = double(indexOfVigenereMatrix+ 64) == c;
    cipher = [cipher, vigenereMatrix(row, col)];
  end
  return;
end