Zevvle with friends and contact privacy

Hello hello hello,

We’ve made a couple of changes to our referral program and the app. Firstly, anyone you refer will also get a share — it felt weird before that they didn’t. We’ve backdated this as well!

Secondly, we’ve added a new tab for contacts, and for anyone you know on Zevvle, there’s a new screen with their call history*:

More on that and how we keep your contacts private:

Have a great weekend :blush:


You won’t be able to see if they’re on Zevvle unless they’ve enabled access to their contacts as well, and if you don’t yet know anyone who’s joined, my phone number is somewhere in the blog — do add & message me! :sunglasses:


I don’t understand, why does it matter whether whether the other person is on Zevvle? Can’t all of these stats be derived from the CDR data, regardless of which carrier the other person is with?

They can! We may show those stats in the future, but have decided not to for now.

Any reason? I don’t understand why someone being on Zevvle or not makes a difference here.

There wasn’t, but we’ll change it! :blush:


Never thought I’d see k-anonymity here. Definitely the right way to go, I’m very impressed! :slightly_smiling_face: It shows you’ve really thought this through.


Looking at the process in more detail, I’m not sure K-Anonymity would work here. Phone numbers are a finite resource, and fast enough machine should be able to precompute all the possible hashes and possibly even keep them all in RAM for fast retrieval.

That should still be okay provided there are enough other phone numbers that there are similar hashes (as the full hash is never sent).