Transfering PIR to Symmetric PIR

vince.h

8/18/24, 10:14 AM

Common PIR schemes only protect the client's privacy, not the server's, while Symmetric PIR(SPIR) can do both.

In many papers, it is mentioned that we can use the Naor and Pinkas method (https://dl.acm.org/doi/pdf/10.1145/301250.301312) to turn a PIR scheme into SPIR one, however when implementing this, I found this method is only useful for one query:

In Protocol 2.1, A use oblivious transfer to pick l keys out of B's 2l keys. This is just allowed to be done once, otherwise A could get most of the 2l keys and decrypt everything she got.

To ensure B's privacy, the database has to change all the 2*l keys (i.e. re-encrypt all the entries) after each query. So I wonder is Naor and Pinkas' method efficient for Symmetric BatchPIR ?

Thanks

0 + 1

oblivious-transfer

pir

Mark

8/18/24, 4:25 PM

I am unfamiliar with SPIR, but my understanding was that PIR that protects both a senders and recievers' privacy was actually Oblivious Transfer (OT), so you may find it useful to look into this notion as well.

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: Transfering PIR to Symmetric PIR

Post an answer

Most people don’t grasp that asking a lot of questions unlocks learning and improves interpersonal bonding. In Alison’s studies, for example, though people could accurately recall how many questions had been asked in their conversations, they didn’t intuit the link between questions and liking. Across four studies, in which participants were engaged in conversations themselves or read transcripts of others’ conversations, people tended not to realize that question asking would influence—or had influenced—the level of amity between the conversationalists.