Authenticated Hash Tables Based on Cryptographic Accumulators

Abstract

Suppose a client stores n elements in a hash table that is outsourced to an untrusted server. We address the problem of authenticating the hash table operations, where the goal is to design protocols capable of verifying the correctness of queries and updates performed by the server, thus ensuring the integrity of the remotely stored data across its entire update history. Solutions to this authentication problem allow the client to gain trust in the operations performed by a faulty or even malicious server that lies outside the administrative control of the client. We present two novel schemes that implement an authenticated hash table. An authenticated hash table exports the basic hash-table functionality for maintaining a dynamic set of elements, A preliminary version of this paper [44] was presented at the 15th 123 Algorithmica coupled with the ability to provide short cryptographic proofs that a given element is a member or not of the current set. By employing efficient algorithmic constructs and cryptographic accumulators as the core security primitive, our schemes provide constant proof size, constant verification time and sublinear query or update time, strictly improving upon previous approaches. Specifically, in our first scheme which is based on the RSA accumulator, the server is able to construct a (non-)membership proof in constant time and perform updates in O (n log n) time for any fixed constant 0 < < 1. A variation of this scheme achieves a different trade-off, offering constant update time and O(n ) query time. Our second scheme uses an accumulator based on bilinear pairings to achieve O(n ) update time at the server while keeping all other complexities constant. A variation of this scheme achieves O(n log n) time for queries and constant update time. An experimental evaluation of both solutions shows their practicality.

New models for efficient authenticated dictionaries

“…However, in 2008Papamanthou et al (2008 propose a cryptographic construction based on RSA accumulators which exploits the efficiency of hash tables. In 2009, the same authors (in Papamanthou et al, 2015Papamanthou et al, , published in 2015 proposed to combine the RSA accumulator with a pairing one in a nested way over a tree of constant depth. Asymptotically the client can optimally authenticate operations on hash tables c o m p u t e r s & s e c u r i t y x x x ( 2 0 1 5 ) 1 e1 2 with constant time and communication complexities.…”

Developing IntegrityCatalog, a software system for managing integrity‐related metadata in digital repositories

“…Another approach is proposed by Papamanthou et al, where an efficient authenticated hash table is introduced, allowing the repository to outsource storage and search computation costs to a third party, while still verifying answers to membership queries are correct. However, this would require network communication to obtain the integrity metadata before verifying any object, severely hindering performance of object verification.…”

Efficient Verifiable Range and Closest Point Queries in Zero-Knowledge

“…We note that range query is not to be confused with range proof [8] where the goal is to prove that the committed value lies in a specified integer range without revealing it. Authenticated data structures (ADS) [14,21,35,36,38,42] are often set in the three party model with a trusted owner, a trusted client and a malicious server; the owner outsources the data to the server and later the client interacts with the server to run queries on the data. The security requirement of such constructions is data authenticity for the client against the server.…”