Can I extract computed result on server side?

Other, random and misc
1

Hi guys! I am new in the HE topic and try understand can I extract computed result on server side without reveal real inputs from client and can I implement it on TFHE-rs or concrete-python?

I have read several similar papers and one proposes validate value after client decrypts it and send back to server, but while I didn’t got it this technics.

Thanks for help!

2

Hi @Boris_Glebov,

It’s not possible to decrypt on the server, as it doesn’t have secret keys :slight_smile:

Could you tell us a bit more about your use case? Maybe with some examples so we can discuss alternatives.

Thanks!

3

Hello! Thank you for responding!

I attempted to create a Proof of Concept (PoC) for a Delivery Service Provider. In this scenario, we have a Customer and multiple Couriers, and we want to share their coordinates with the Service Provider (SP). However, the SP needs to match the Customer with the nearest Couriers. I’m unsure about how to select Couriers who are close to the Customer and send order for their.

I came across a similar paper (https://www.usenix.org/system/files/conference/usenixsecurity17/sec17-pham.pdf), where they calculate the distances of all drivers in a specific region and send them to the Customer for decryption.

4

It is possible to compute the distance in two cases:

  • between two encrypted vectors
  • between one encrypted vector and one clear vector

I’m not sure which one you would need but both are pretty easy to do in Concrete-Python

5

I correct understand, that we can calculate distance between two encrypted location, but distance will be encrypted too and on server side I cant check that its’ less or equal some constant?