Who said I was going to announce the hashing algorithm used?

Yes, that is right, I'm talking about security through obscurity!

I was going to obscure the hashing algorithm used just like Fletch proposes obscuring the "not-public salt". But I considered that too obvious to mention since using a known hash on something as tiny as an IP address would be silly to the point of being stupid, no?

Thanks for mentioning that, Fletch. That interpretation would have likely never occurred to me. :)