Continuing the series of posts on the architectural considerations for designing a predominantly-Microsoft IT infrastructure, based on the MCS Talks: Enterprise Infrastructure series, in this post I’ll look at some of the infrastructure architecture considerations relating to security.

The main security challenges which organisations are facing today include: management of access rights; provisioning and de-provisioning (with various groups of users – internal, partners and external); protecting the network boundaries (as there is a greater level of collaboration between organisations); and controlling access to confidential data.

Most organisations today need some level of integration with partners and the traditional approach has been one of:

• NT Trusts (rarely used externally) – not granular enough.
• Shadow accounts with matching usernames and passwords – difficult to administer.
• Proxy accounts shared by multiple users – with no accountability and a consequential lack of security.

Federated rights management is a key piece of the “cloud computing” model and allows for two organisations to trust one another (cf. an NT trust) but without the associated overheads – and with some granularity. The federated trust is loosely coupled – meaning that there is no need for a direct mapping between users and resources – instead an account federation server exists on one side of the trust and a resource federation server exists on the other.

As information is shared with customers and partners traditional location-based methods of controlling information (firewalls, access control lists and encryption) have become ineffective. Users e-mail documents back and forth, paper copies are created as documents are printed, online data storage has become available and portable data storage devices have become less expensive and more common with increasing capacities. This makes it difficult to set a consistent policy for information management and then to manage and audit access. It’s almost inevitable that there will be some information loss or leakage.

(Digital) rights management is one solution – most people are familiar with DRM on music and video files from the Internet and the same principles may be applied to IT infrastructure. Making use of 128-bit encryption together with policies for access and usage rights, rights management provides persistent protection to control access across the information lifecycle. Policies are embedded within the document (e.g. for the ability to print, view, edit, or forward a document – or even for it’s expiration) and access is only provided to trusted identities. It seems strange to me that we are all so used to the protection of assets with perceived worth to consumers but that commercial and government documentation is so often left unsecured.

Of course, security should be all-pervasive, and this post has just scratched the surface looking at a couple of challenges faces by organisations as the network boundaries are eroded by increased collaboration. In the next post of this series, I’ll take a look at some of the infrastructure architecture considerations for providing high availability solutions.