Tisa: Towards Trustworthy Services in a Service-oriented Architecture

By: Hridesh Rajan and Mahantesh Hosamani

Abstract

Verifying whether a service implementation is conforming to its service-level agreements is important to inspire confidence in services in a service-oriented architecture. A part of these agreements, in particular those that are functional in nature, can be checked by observing the published interface of the service, but other agreements that are more non-functional in nature, are often verified by deploying a monitor that observes the execution of the service implementation. A key problem is that such a monitor must execute in an untrusted environment (at the service provider’s site). Thus, integrity of the results reported by such a monitor crucially depends on its integrity. The key technical contribution of this article is an extension of the traditional notion of a service-oriented architecture that allows clients, brokers and providers to negotiate and validate the integrity of a requirements monitor. We describe an approach, based on hardware-based root of trust, for verifying the integrity of a requirements monitor executing in an untrusted environment. We make two basic claims: first, that it is feasible to realize our approach using existing hardware and software solutions, and second, that integrity verification can be done at a relatively small overhead. To evaluate our feasibility claim, we present a realization of our approach using a commercial requirements monitor. To measure overhead, we have conducted a case study using a collection of web service implementations available with Apache Axis implementation.

ACM Reference

Rajan, H. and Hosamani, M. 2008. Tisa: Towards Trustworthy Services in a Service-oriented Architecture. IEEE Transactions on Services Computing (SOC). 1, (2008).

BibTeX Reference

@article{rajan2008tisa,
  author = {Hridesh Rajan and Mahantesh Hosamani},
  title = {Tisa: Towards Trustworthy Services in a Service-oriented Architecture},
  journal = {IEEE Transactions on Services Computing (SOC)},
  volume = {1},
  number = {},
  year = {2008},
  publisher = {IEEE Computer Society},
  address = {Washington, DC, USA},
  abstract = {
    Verifying whether a service implementation is conforming to its service-level
    agreements is important to inspire confidence in services in a
    service-oriented architecture. A part of these agreements, in particular those
    that are functional in nature, can be checked by observing the published
    interface of the service, but other agreements that are more non-functional in
    nature, are often verified by deploying a monitor that observes the execution
    of the service implementation.

    A key problem is that such a monitor must execute in an untrusted environment
    (at the service provider's site). Thus, integrity of the results reported by
    such a monitor crucially depends on its integrity.

    The key technical contribution of this article is an extension of the
    traditional notion of a service-oriented architecture that allows clients,
    brokers and providers to negotiate and validate the integrity of a
    requirements monitor. We describe an approach, based on hardware-based root of
    trust, for verifying the integrity of a requirements monitor executing in an
    untrusted environment. We make two basic claims: first, that it is feasible to
    realize our approach using existing hardware and software solutions, and
    second, that integrity verification can be done at a relatively small
    overhead. To evaluate our feasibility claim, we present a realization of our
    approach using a commercial requirements monitor. To measure overhead, we have
    conducted a case study using a collection of web service implementations
    available with Apache Axis implementation.
  }
}