Generating a 30-32-bit PRP I want to generate a small 30 or 32 bit PRP. I am going to use that PRP in an open web service and anyone will be able to get any number of plaintext-cyphertext pairs.

I've found an algorithm called FastPRP and the problem statement fits my requirements perfectly. However the performance seems quite low for 30-32 bit range.
I need a high-performant point evaluations for both PRP and an inverse PRP. 

Are there any 32-bit PRP algorithms (less secure probably) that allow a faster point evaluations?
If you need a 32 bit PRP, might I suggest the Speck cipher?  It isn't greatly secure (with a 32 bit block size, the only option is a 64 bit key, which isn't great), however it's extremely fast.