Robert Primmer

Robert Primmer

In this paper we look at the growth of distributed object stores (DOS) and examine the underlying mechanisms that guide their use and development. Our focus is on the fundamental principles of operation that define this class of system, how it has evolved, and where it is heading as new markets expand beyond the use originally presented. We conclude by speculating about how object stores as a class must evolve to meet the more demanding requirements of future applications.

Robert Primmer, Carl D'Halluin

Centera uses cryptographic hash functions as a means of addressing stored objects, thus creating a new class of data storage referred to as CAS (content addressed storage). Such hashing serves the useful function of providing a means of uniquely identifying data and providing a global handle to that data, referred to as the Content Address or CA. However, such a model begs the question: how certain can one be that a given CA is indeed unique? In this paper we describe fundamental concepts of cryptographic hash functions, such as collision resistance, pre-image resistance, and second-preimage resistance. We then map these properties to the MD5 and SHA-256 hash algorithms, which are used to generate the Centera content address. Finally, we present a proof of the collision resistance of the Centera Content Address.