nSignMode
Flag that indicates the type of message authentication code to be used. Possible values are:
| Value | Meaning | 
| DICOM_ISCL_MAC_NONE | [0x00000000]No message authentication code will be used. | 
| DICOM_ISCL_MAC_MD5 | [0x00001441]A 128 bit MD5 message authentication code is transmitted with the message. | 
| DICOM_ISCL_MAC_DESMAC | [0x00004001]A 64 bit DESMAC authentication code is transmitted with the message. | 
If a wrong value is passed, the message authentication code will be of type DICOM_ISCL_MAC_MD5.