Changed access modifier for Cryptor constructor.
Extracted magic constants.
More magic constants.
Joined variable declaration.
Changed catch-clause to specific Exception.
Refactored method names.
Extracted file encoding to constant.
Changed to use StringBuilder instead of concatenating strings.
Changed multiple close-statements to use try-with-resources.
Moved methods for better clarity.
Renamed variables and methods for better clarity.
Extracted encryption algorithm to Encryptor.
Created CryptorUtils.
Created Decryptor.
Extracted encryptCharacters to Encryptor.