Grid Computing aims to integrate large number
of heterogeneous, geographically distributed
resources and services to create the illusion of a
simple and powerful virtual supercomputer. Clearly,
security is a serious concern in such a big
environment. The environment needs to be secure in
terms of access and communication in order for it to
be widely used and acceptable. The large number of
user base and administrative domains, with differing
security requirements, policies and trust relationships,
interact in a complex manner to access resources. This
give rise to security problems that are not addressed
by traditional distributed computing environments.
This paper presents, at a high level, web services
security specifications based security model to address
security requirements of grid services. The model is
simple, flexible, adaptable and is based on extended
use of web services security specifications. We also
present a prototype implementation of the proposed
model.