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Questions tagged [oblivious-ram]

Oblivious RAM (O-RAM) is a useful primitive that allows a client to hide its data access patterns from an untrusted server in storage outsourcing applications.

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Computationally secure ORAMs with O(lg n)-bit words: shouldn't they fail with $n^{-O(1)}$ probability?

Virtually all "hierarchical" Oblivious RAMs use "cryptographically secure" hash functions to determine the position of an item at a given level; and implicitly assume (as can be evinced from the cost ...
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Path ORAM asymptotics for arbitrary block sizes

The Path-ORAM construction assumes that the data outsourced into the ORAM scheme is split into blocks of size $\Omega(\log^2{n})$. With respect to this assumption the authors state that their storage ...
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How is the re-encryption done in Path ORAM?

Path ORAM block headers store nonce that is used to re-encrypt the data on access. Every time a block is accessed, the nonce is ...
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Why is on-chip data considered to be secure in secure processor setting?

I was taking a look into the paper PHANTOM: Practical Oblivious Computation in a Secure Processor. The introduction says, Confidentiality of data is a major concern for enterprises and ...
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Efficiency of oblivious algorithms vs non-oblivious algorithms?

Recently, plenty of researchers are looking at designing efficient data-oblivious algorithms. Roughly speaking, an algorithm is said to be data-oblivious if its data access patterns are independednt ...
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Are any of the practical implementations of ORAM being used in a real world system?

The concept of Oblivious RAM (ORAM) was first introduced by Oded Goldreich and Rafail Ostrovsky in 1996. However, in the past 5-10 years there has been a surge in the amount of research that looks ...
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ORAM over Third Party DB

Oblivious Ram (ORAM) is a cryptographic technique that is used for secure DB querying without leakage on the access patterns. There are several schemes for ORAM, amongst the most popular ones, there ...
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About ORAM initalization and running out of space

I have two questions about ORAM Since at the beginning,the server allocates unused storage for ORAM cient,there are no user's data in the storage.if now client access the storage the server will know ...
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PathORAM with read path eviction

I am currently trying to implement the pathORAM algorithm as describe in this paper: https://eprint.iacr.org/2013/280.pdf The paper states that with high probability, the stash size will be bounded ...
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Optimal bandwidth cost for Oblivious RAM

Goldreich and Ostrovsky show that any ORAM algorithm must have bandwidth cost $\Omega(logN)$, where $N$ is the total number of blocks outsourced. This is in Theorem C of this paper. But they didn't ...
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Which concrete applications benefit from Oblivious RAM constructions?

The main motivation for Oblivious RAM (ORAM) is that, for instance, in the "cloud" setting a client outsources his data to a server in the form of encrypted blocks. Later on, he wants to perform read ...