[waffle_ss]

I wrote a Ruby gem to address this problem of hiding sequential primary keys that uses a Feistel network to effectively shuffle int64 IDs: https://github.com/abevoelker/gfc64

So instead of

    /customers/1
    
    /customers/2

You'll get something like

    /customers/4552956331295818987
    
    /customers/3833777695217202560

Kinda similar idea to this library but you're encoding from an integer to another integer (i.e. it's format-preserving encryption). I like keeping the IDs as integers without having to reach for e.g. UUIDs

[wslh]

I recommend to review my comment where I also use a Feistel cipher [1] but the difference is that it is not limited to int64 but I can even use 8 bits. Obviously loosing security properties but working as an obfuscation method. If you use a random source with relatively few bits you should check if there are duplicates while with the Feistel cipher you are sure there isn't.

[1] https://news.ycombinator.com/item?id=38418198