# Tag Info

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In general, PIR mainly guarantees that the server should not know which item is retrieved, as does OT. However, in contrast to PIR, OT also guarantees that the user should not learn information about other items. ----update based on Lindell's comment---- Another difference between PIR and OT is the requirement of sublinear communication cost for PIR. Note ...

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Efficiency of PIR largely depends whether you have a single-server or a multi-server PIR (replicate the database $n>1$ times). Multi-server PIR seems more attractive (Ian Goldberg does a lot of research into this direction, e.g., this paper is the basis for most multi-server PIR approaches). Considering the database to be organized in a $r\times s$ ...

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Information theoretic PIR protocols that have communication complexity less than the size of the database require multiple, non-cooperating servers [1]. In a computational setting, this is not required. So if you do not want to have to share your database with multiple servers, you should probably use a computational PIR protocol. 1. https://en.wikipedia....

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When the servers may collude then if they are all corrupted it's exactly the same as 1-server PIR. Thus, in information-theoretic PIR, it is always assumed that only some subset of the servers are corrupted. It is unclear to me what you would gain by running MPC between the servers. One possibility is to simulate a single-server PIR with many servers. But ...

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ORAM can be built on a multi-party scenario, where the data belongs to various parties using Secure Multiparty Computation. Recent research calls this approach ORAM for Secure Computation (SC-ORAM). Given that writing and reading are required, it is my believe this would be the best approach. In the typical SC-ORAM setting, several parties store ...

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The solution proposed in this (dated) work is an overkill considering more recent works on the subject. The simplest PIR by keyword construction I could think of is the one based on distributed point functions (DPFs). see https://cs.idc.ac.il/~elette/FunctionSecretSharing.pdf Distributed point functions are a special case of function secret sharing (FSS). ...

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Kolesnikov & Kumaresan defined a primitive called "string select OT" which basically covers your setting but with a database of 2 items. Sender has $x^1, y^1, x^2, y^2$. Receiver has $x^*$. If $x^* = x^i$ then the receiver learns the corresponding $y^i$. I think a generalization of their protocol would work, at the cost of $n$ 1-out-of-2 string OTs ...

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