Authentic Third-party Data Publication

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.