cipher_key_mappings_complete.rb

ciphertexts = [                                                                              
  "VGYURYPEDFNCEPGEWELLPVNWRDCNFGMGXQEPPRG-CBFIGLEMG",                                       
  "EQ’PMEIGQNVBAGBTFEGMSYNRKMNWEPBLWBYPSNWMQNFBDWEQVYNR-CBFIGLEMG"                           
]                                                                                            

cipher_keys  = "CBFIGLEMGQPRXWYNVDUATSK"                                                     
key_mappings = "MARCELINETSUXWYOHPGVFDK"                                                     

known_keys   = cipher_keys.chars                                                             
all_keys     = ("A".."Z").to_a                                                               
unknown_keys = (all_keys - known_keys)                                                       

ciphertexts.each do |ciphertext|                                                             
  ciphertext_before = ciphertext                                                             
  ciphertext_after  = ciphertext.tr(cipher_keys, key_mappings)                               
  ciphertext_known_keys = ciphertext.tr(unknown_keys.join, "_").tr(cipher_keys, key_mappings)

  puts "Ciphertext before:     #{ciphertext_before}"                                         
  puts "Ciphertext after:      #{ciphertext_after}"                                          
  puts "Ciphertext known keys: #{ciphertext_known_keys}"                                     
end