Encrypting with X 509 Certificates

// Encrypt the message body with the credit card details using the
// Accounts Department Certificate
X509SecurityToken x509Cert = GetFabrikamAccountsDepartmentCertificate();
paymentServiceProxy.RequestSoapContext.Security.Tokens.Add( x509Cert );
paymentServiceProxy.RequestSoapContext.Security.Elements.Add( new EncryptedData( x509Cert ) );