I am interested if it's possible to do string encryption/decryption using Excel Visual Basic and some cryptographic service provider. I have found a walkthrough [Encrypting and Decrypting Strings in Visual Basic][1], but it seems it's valid for standalone Visual Basic only. So would you suggest me another encryption method or show how the walkthrough could be adopted for Excel Visual Basic? [1]: http://msdn.microsoft.com/en-us/library/ms172831.aspx