C# Encrypt Text Output

Question

I have created a few little programs that export data to a text file using StreamWriter and then I read them back in using StreamReader. This works great and does what I nee

Answer 1

You should call ProtectedData.Protect to encrypt the data using a per-user key.

Note that it wouldn't be very hard for a skilled user to decrypt and modify the data.
Anything that your program does on the user's machine can be done by the user too.