Authentic Third-Party Data Publication

Abstract

Integrity critical databases, such as financial information, which are used in high-value decisions, are frequently published over the internet. Publishers of such data must satisfy the integrity, authenticity, and non-repudiation requirements of end clients. Providing this protection over public data networks is an expensive proposition. This is, in part, due to the difficulty of building and running secure systems. In practice, large systems can not be verified to be secure and are frequently penetrated. The negative consequences of a system intrusion at the publisher can be severe. The problem is further complicated by data and server replication to satisfy availability and scalability requirements.To our knowledge this work is the first of its kind to give general approaches for reduce the trust required of the publisher of large, infrequently updated databases. To do this, we separate the roles of owner and publisher. With a few digital signatures on the part of the owner and no trust required of the publisher, we give techniques based on Merkle hash trees, that publishers can use to provide authenticity and non-repudiation of the answer to a database query. This is done without requiring a key to be held in an on-line system, thereby reducing the impact due to the likely system penetration. By reducing the trust required of the publisher, our solution is a step towards the publication of large databases in a scalable manner.

Signature Bouquets: Immutability for Aggregated/Condensed Signatures

“…Multi-querier: a database is owned by a single client but multiple queriers are allowed to query the hosted database. This scenario is very similar to authentic third-party publication [10]. 3.…”

“…The querier can then easily construct legitimate and authentic query replies for un-posed queries, since she is free to manipulate individual record-level signatures. Furthermore, other methods, such as the constructs based on Merkle Hash Trees (MHTs) suggested by Devanbu, et al [10], are equally susceptible to mutability of authentic query replies. (In [10], a querier obtains a set of records matching a posed query along with a set of of non-leaf nodes of an MHT.…”

“…Furthermore, other methods, such as the constructs based on Merkle Hash Trees (MHTs) suggested by Devanbu, et al [10], are equally susceptible to mutability of authentic query replies. (In [10], a querier obtains a set of records matching a posed query along with a set of of non-leaf nodes of an MHT. The exact composition of this set depends on the type of a query.)…”

“…Other relevant prior work [10][15] examined integrity issues in outsourced databases and suggested some limited solutions 1 . Recently, more general techniques were investigated in [19] where two signature schemes were proposed for efficient integrity and authenticity support in querying outsourced databases.…”

“…Each scheme enables bandwidth-and computation-efficient integrity verification for any possible query reply. However, as shown below in more detail, the schemes in [19] (as well as those in [10]) are mutable, i.e., any entity in possession of multiple authentic query replies can derive other, equally authentic query replies.…”