Data update

Task/Bifid-cipher/Ruby/bifid-cipher.rb

@@ -0,0 +1,65 @@
+def cleanMsg(msg, square)
+  msg.upcase!
+  msg.delete!(' ')
+  msg.delete!('J') if square.index('J') == nil
+end
+
+def encrypt(msg, square)
+  cleanMsg msg, square
+  sq_size = (square.length ** 0.5).to_i
+  rows = [0] * msg.length
+  cols = [0] * msg.length
+  (0...msg.length).each do |i|
+    p = square.index(msg[i])
+    rows[i], cols[i] = p / sq_size, p % sq_size
+  end
+  result = ""
+  rows.concat(cols).each_slice(2) do |coord|
+    result += square[coord[0]*sq_size + coord[1]]
+  end
+  return result
+end
+
+def decrypt(msg, square)
+  msg.upcase!; square.upcase!
+  sq_size = (square.length ** 0.5).to_i
+  coords = []
+  result = ""
+  (0...msg.length).each do |i|
+    p = square.index(msg[i])
+    coords << p / sq_size
+    coords << p % sq_size
+  end
+  for i in (0...coords.length/2) do
+    row, col = coords[i], coords[i+coords.length/2]
+    result += square[row*sq_size + col]
+  end
+  return result
+end
+
+def printSquare(square)
+  sq_size = (square.length ** 0.5).to_i
+  (0..square.length).step(sq_size).each do |i|
+    print square[i...(i+sq_size)], "\n"
+  end
+end
+
+tests = [["ATTACKATDAWN" , "ABCDEFGHIKLMNOPQRSTUVWXYZ"],
+         ["FLEEATONCE"   , "BGWKZQPNDSIOAXEFCLUMTHYVR"],
+         ["ATTACKATDAWN" , "ABCDEFGHIKLMNOPQRSTUVWXYZ"],
+         ["the invasion will start on the first of january", "BGWKZQPNDSIOAXEFCLUMTHYVR"],
+         ["THIS MESSAGE HAS NUMBERS 2023", "ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890"],
+]
+
+for test in tests
+  message = test[0]; square = test[1];
+  encrypted = encrypt(message, square)
+  decrypted = decrypt(encrypted, square)
+
+  puts "using the polybius:"
+  printSquare(square)
+  puts "the plain message:", message
+  puts "encrypted:", encrypted
+  puts "decrypted:", decrypted
+  puts "===================================================="
+end