[PDF] Top 20 Yes, There is an Oblivious RAM Lower Bound!

... an oblivious RAM lower bound?”, there are two caveats with the lower bound of Goldreich and Ostrovsky: (1) it only applies to “balls in bins” algorithms, ...linear lower ... See full document

... an Oblivious RAM (ORAM) with constant worst-case bandwidth blowup that leverages poly-logarithmic server computation to circumvent the logarithmic lower bound on ORAM bandwidth ... See full document

... Network RAM analog of the Oblivious Parallel RAM (OPRAM) model by Boyle et ...ORAM lower bound (in the sequential execution model) directly implies the following lower ... See full document

... their lower bound is restricted to schemes that treat the contents of each memory word as “indivisible” (see Boyle and Naor [7]) and make no cryptographic ...the lower bound, but unfortunately ... See full document

... ) lower bound, several works have looked at different refinements of the classical ORAM notion in the client server ...Verifiable Oblivious Storage, which generalizes the notion of ORAM by allowing ... See full document

... and oblivious transfer protocols, among others. Oblivious transfer (OT) is a fundamental primitive since it is complete for secure multi- party computation, and the OT capacity characterizes how efficiently ... See full document

... Henceforth in this paper, we consider ORAMs to be a special case of OPRAMs, i.e., when both the original PRAM and the OPRAM have only one CPU. To characterize an OPRAM scheme’s overhead, we will use the standard ... See full document

... a lower bound on the amortized communication complex- ity required to maintain ...a lower bound result of O(log C N ) blocks of bandwidth overhead for any ORAM construction for a database of ... See full document

... leaves that can store all the N items. I.e. a total storage of only O(N ) items at the server. This also improves the complexity: instead of traversing a log N height tree and going over O(log N ) items in each level ... See full document

... Given that pruning an entire level at once is very inefficient, we now investigate how pruning can be done in a more gradual way. For every α elements we delete, we will prune two children and merge their contents into ... See full document

... We now exploit that fact that typically there will be many more blocks free than just one. We set k such that in expectation we will have one (or slightly more than one) free blocks, e.g., by setting k to only 4. The ... See full document

... logarithmic lower bound on ORAM bandwidth blowup shown by Goldreich and Ostrovsky [18, 19, 32], it is now well-understood that this lower bound can be circumvented by leveraging server-side ... See full document

... Theorem 1.1 (OPRAM – Informally stated). There exists an OPRAM compiler with O(log(m) log 3 (n)) worst-case overhead in total and parallel computation, and f(n) memory overhead for any f ∈ ω(1), where n is the memory ... See full document

... 4. Removing duplicates takes place via three sub-steps. First, the duplicate items are identi- fied (and replaced by −∞ symbols) by a one-pass over the data. In order to remove them obliviously (since their location is ... See full document

... a lower bound of Ω (log n) on the ORAM overhead, where n denotes the number of memory blocks in the logical ...this bound [SvDS + 13, WCS15], at least if the block size is set to a sufficiently large ... See full document

... efficient oblivious RAM (ORAM) protocol providing oblivious access (read and write) of a memory index y in exactly two rounds: The client prepares an encrypted query encapsulating y and sends it to ... See full document

... We evaluate our design in terms of performance and area. Performance is measured as the latency (in FPGA cycles or real time) between when an FPGA user design requests a block and Tiny ORAM returns that block. Area is ... See full document

... garbled RAM program, using a sequence of garbled circuits, one would expect that the simulation of garbled circuits would be done from the first CPU step to the last CPU ... See full document

... Finally, an interesting application comes from the release of Intel’s new SGX- enabled processors. SGX enables a trusted enclave to run protected code which cannot be examined from the outside, even by the operating ... See full document

... Scope. Our main security goal is to guarantee oblivious- ness i.e., hide read access patterns of users from the cloud provider. Although we consider a compromised server, we do not defend against a cloud provider ... See full document