I am implementing a password/login dialog and I want to use the definitions in the header file wincrypt.h . I have included the functions for encrypting and decrypting the password in the same class as the dialog (CDialog) but even though I included the wincrypt.h file, the compiler won't understand these definitions:

HCRYPTPROV hProv;
HCRYPTKEY hKey;

What kind of class do I have to use in order to work with the definitions in wincrypt.h?.
What am I doing wrong?.
Please help me.

Thanks in advance.