Encryption - D-Link DSM-750 - MediaLounge High-Definition Draft N Media Player User Manual

Section  - Configuration
Select your wireless network from the list of networks that appear.
Note: If you do not see your wireless network, refer to the "Wireless
Installation Considerations and Troubleshooting" section starting on page
109 for information as to why this may have happened.

Encryption

If your wireless home network is using wireless encryption, you will need to
provide the DSM-750 with the network security passphrase. By using the On
Screen Keyboard, you may enter the network security passphrase.
D-Link DSM-750 User Manual