Quite often people use X509Certificate2 object to instantiate a RSACryptoServiceProvider object: var rsaObj = new X509Certificate2("some-cert.p12", "password", X509KeyStorageFlags.Exportable | X509KeyStorageFlags.MachineKeySet).PrivateKey as RSACryptoServiceProvider; I want to generate the RSACryptoServiceProvider object using private and public keys defined as strings, without going through X509Certificate. Please help!