I have no personal experience with Curtin but can assure you that it is a completely legitimate institution. It is a public university in Western Australia.
Several years ago, I exchanged emails with a professor at Curtin with the intent to enter one of their doctoral programs. I was very impressed with the professor and the program, but chose to enter Touro and pursue a business administration Ph.D. One of my professors at Touro earned a masters degree at Curtin. The university is well-respected in Australia but not well known in North America. You didn't mention any specific information, so I hope this is of use to you. Dave