These two products can help you protect sensitive application settings, such as database connection strings, passwords, and encryption keys. Both run on Windows® operating systems and require a .NET Framework. Both are simple to use. One is free, the other is not.

CipherSafe.NET (commercial)

CipherSafe.NET manages sensitive application settings of various types of Windows® applications, including ASP/ASP.NET, Web services, executable files, dynamic-link libraries, directories, scripts, and more. CipherSafe.NET offers the most secure and easy to use solution for protecting sensitive application settings currently available on the market.

CipherLite.NET (freeware)

CipherLite.NET is a simple utility that allows you to encrypt and decrypt data. It comes with a GUI tool and a helper library. You can use the provided GUI to encrypt data using DPAPI or a Rijndael (AES) symmetric key and save the encrypted value in the application configuration file or Windows® registry. CipherLite.NET can also be used to hash data.