Broadcast a private wireless network from Mac to iPhone via ethernet Situation: I use my mac's ethernet for internet, because my apartment doesn't have a working router. However, I need wifi for my iPhone. Wifi is available from other apartments in the same building, however it's a weak/slow network speed. 

Question: Can I setup a wifi hotspot coming from my Mac, that is connected to the internet via ethernet? This hotspot would require a password, so only my iPhone can connect to it.

Models: mid-2012 Macbook Pro Retina. Updated to Yosemite 10.10.2. iPhone 5s, updated to current software available, I don't remember the number.

Research: I have researched this topic. Majority are out of date, or are about iPhone TO mac hotspot, rather than Mac TO iPhone. Or they discuss from wifi to wifi. Seems no one uses ethernet anymore. (Ethernet OP btw).

Thank you! Hope I provided enough information.
On the Mac, go to System Preferences > Sharing. In the list on the left-hand side, check the box for Internet Sharing, then ensure your current connection (probably listed as Ethernet) is selected in the combobox. In the checklist below that, check the box for Wi-Fi.

(In the screenshot, Internet Sharing on the left is not checked, but it must be for this to work.)

The Wi-Fi Options button allows you to set the network name (SSID) and password.