system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] If Luke's identity was to be protected from Vader, why did he retain his Skywalker surname?
gpt
Two main reasons:

1. Everyone was told that Padme died and her child died with her. Thus Vader and the Emperor *weren't even looking* for Luke and Leia.

2. Obi-Wan took him back to Tatooine - not only is this planet outside of the Empire's jurisdiction, it's a reminder of *Anakin Skywalker*'s past - a past that Vader does his best to avoid.