Private Information Retrieval - Wikidata

29 Jan 2022

Dear all,

I started using WikiData for Private Information Retrieval. This allows 
answering certain questions while maintaining a high degree of secrecy. 
Suppose you wanted to know when Einstein was born, but for some reason you 
must keep the fact that you want to know this a secret. In this case, we 
assume a threat model with perfect knowledge about the computer in use, not 
just that someone managed to log the Wikidata requests.

One solution would be to request a table of every human who ever won the 
Nobel Prize (this requires the common knowledge of Einstein being a winner 
of said) with the kind of Nobel Prize, date awarded, date of birth, date of 
death unless living, nationality etc. If we let this table scroll across 
the screen and read the required entry, there would be - as far as I can 
tell - no way to learn which entry (and how many of them) is of our 
interest.

I have written a simple PHP script that allows one to enter a SPARQL 
request and have it displayed as a scrolling table. Please be advised that 
this is in a very informal alpha state, and I am no professional Web 
Developer. It's a mere proof-of-concept, but feel free to try it out if the 
API quota lets you.

https://darius-runge.eu/otp/request.php

My question is, whether anyone of you might be interested in working with 
me on discussing practical implications of this method (how should requests 
be written to allow for the desired privacy?) or even making a better 
implementation of a tool that allows viewing the scrolling table of 
printing it out.

Feel free to reply to this mailing list entry or contact me privately with 
the postal or telecommunication data provided in the footer in case you 
don't want to discuss it in public.

Best,
Darius

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Darius Runge
Postfach 3
72669 Unterensingen
Germany

Tel +49 7022 5064970
Fax +49 7022 5064971
Vox +49 7022 5064998 (2 min)

All up-to-date contact data:
https://darius-runge.eu