This paper proposes a protocol suite for dynamic replication and migration of Internet objects. It consists of an algorithm for deciding on the number and location of object replicas and an algorithm for distributing requests among currently available replicas. Our approach attempts to place replicas in the vicinity of a majority of requests while ensuring at the same time that no servers are overloaded. The request distribution algorithm uses the same simple mechanism to take into account both server proximity and load, without actually knowing the latter. The replica placement algorithm executes autonomously on each node, without the knowledge of other object replicas in the system. The proposed algorithms rely on the information available in databases maintained by Internet routers. A simulation study using synthetic workloads and the network backbone of UUNET, one of the largest Internet service providers, shows that the proposed protocol is effective in eliminating hot spots and ...

We present an approach to authenticating photo-ID documents that relies on pattern recognition and public-key cryptography and has security advantages over physical mechanisms that currently safeguard cards, such as optical laminates and holograms. The pattern-recognition component of this approach is based on a photo signature that is a concise representation of the photo image on the document. This photo signature is stored in a database for remote authentication or in encrypted form on the card for stand-alone authentication. Verification of the ID document entails scanning both the photo image and a machine-readable form of the text information, determining the photo signature, and comparing this information against the reference. In this paper, we describe the method and present results of testing a large database of images for photo-signature match in the presence of noise.

Personal identification documents such as ID-cards are being used increasingly for such activities as cashless transactions, entry into restricted areas, and personal verification for medical and government services. With this trend, there is also the increasing trend toward counterfeiting these documents for illegal gain. We present an approach to authenticating photo-ID documents that relies on pattern recognition and cryptography, and has cost and security advantages over physical mechanisms such as holograms that are currently used. The approach is based on a photo-signature that is a concise representation of the photo-image on the document. This photo-signature is stored in a database for remote verification or in encrypted form on the card for self-verification. Verification of the ID document entails scanning both the photo-image and a machine-readable form of the text information, determining the photo-signature, and comparing this information against the reference. In this paper, we describe the method, and present results of testing a large database of images for photo-signature match in the presence of noise.