Auth library

[eluser]pmoroom[/eluser]
Hello folks,

I've spent the last several months trying various frameworks to find out which one would best suit my needs. After trying dozens with magic I am leaning back towards CI. One think that is very important to me is user auth. I've seen the various auth libraries available for CI, but not exactly sure which one I should land on (I have not actually tried any within the code, just read about them.) so I'm reaching out to you all to get your take on the best one. My requirements are below:

#1 - solid security (tested and test cases)
#2 - hashing of passwords (salt)
#3 - ACL (not a deal breaker, but would be nice)

What would you guys/girls recommend as a starting point here?