Require obfuscated server connection
Require obfuscated server connection makes sure that only obfuscated traffic to servers is send and received.
This has at the time of creation the big advantage that no connections to fake/ad servers are made since they do not support obfuscation. The protocol how to make obfuscated connections to a server is open source and documented, so in the future bad server might also appear. But for now you can freeley accept servers form server since fake server are filtered out.
A side effect of obfuscated connection is that no-one can spy on your traffic on change it simple. But remember that obfuscation does not make eMule a anonymous application.
To make a obfuscated connection to server first a encryption (obfuscation is done by encryption) key has to be exchanged. This can be done by a udp "cryptping" package, or by making a not obfuscated connection. if udp fails or no previous connection has been made then the obfuscation will fail and the connection will not be made. As of morph 9.6 there is no gui indication if a valid encyption key is available.
The "required obfuscated server connection" option is independent of of the security settings. SO most of your cleint connections can still be not obfuscated. Only if you disable obfuscation in the security settings completely this otpion will also be disabled.
obfuscation also makes that ip adress of servers can not be faked in udp traffic.
Note that official has a "require obfuscated" option, but that still allows unencrypted connections to servers that do not support it. Also "require obfuscated" is not recommended since you cannot connect to other clients that do not support it, limiting the number of sources you can reach by a lot.
Note that by default on official obfuscation is supported, but not enabled. This means that obfuscated connections are accepted, but not initiated by the client.