Enterprise information security architecture

Enterprise information security architecture (EISA) is a part of enterprise architecture focusing on information security throughout the enterprise. The name implies a difference that may not exist between small/medium sized businesses and larger organizations.

Overview

Enterprise information security architecture (EISA) is the practice of applying a comprehensive and rigorous method for describing a current and/or future structure and behavior for an organization's security processes, information security systems, personnel and organizational sub-units, so that they align with the organization's core goals and strategic direction. Although often associated strictly with information security technology, it relates more broadly to the security practice of business optimization in that it addresses business security architecture, performance management and security process architecture as well.

Enterprise information security architecture is becoming a common practice within the financial institutions around the globe. The primary purpose of creating an enterprise information security architecture is to ensure that business strategy and IT security are aligned. As such, enterprise information security architecture allows traceability from the business strategy down to the underlying technology.

Enterprise information security architecture topics

Positioning

Enterprise information security architecture was first formally positioned by Gartner in their whitepaper called “Incorporating Security into the Enterprise Architecture Process”. This was published on 24 January 2006. Since this publication, security architecture has moved from being a silo based architecture to an enterprise focused solution that incorporates business, information and technology. The picture below represents a one-dimensional view of enterprise architecture as a service-oriented architecture. It also reflects the new addition to the enterprise architecture family called “Security”. Business architecture, information architecture and technology architecture used to be called BIT for short. Now with security as part of the architecture family it has become BITS.

Security architectural change imperatives now include things like

Business roadmaps
Legislative and legal requirements
Technology roadmaps
Industry trends
Risk trends
Visionaries

Goals

Provide structure, coherence and cohesiveness.
Must enable business-to-security alignment.
Defined top-down beginning with business strategy.
Ensure that all models and implementations can be traced back to the business strategy, specific business requirements and key principles.
Provide abstraction so that complicating factors, such as geography and technology religion, can be removed and reinstated at different levels of detail only when required.
Establish a common "language" for information security within the organization

Methodology

The practice of enterprise information security architecture involves developing an architecture security framework to describe a series of "current", "intermediate" and "target" reference architectures and applying them to align programs of change. These frameworks detail the organizations, roles, entities and relationships that exist or should exist to perform a set of business processes. This framework will provide a rigorous taxonomy and ontology that clearly identifies what processes a business performs and detailed information about how those processes are executed and secured. The end product is a set of artifacts that describe in varying degrees of detail exactly what and how a business operates and what security controls are required. These artifacts are often graphical.

Given these descriptions, whose levels of detail will vary according to affordability and other practical considerations, decision makers are provided the means to make informed decisions about where to invest resources, where to realign organizational goals and processes, and what policies and procedures will support core missions or business functions.

A strong enterprise information security architecture process helps to answer basic questions like:

What is the information security risk posture of the organization?
Is the current architecture supporting and adding value to the security of the organization?
How might a security architecture be modified so that it adds more value to the organization?
Based on what we know about what the organization wants to accomplish in the future, will the current security architecture support or hinder that?

Implementing enterprise information security architecture generally starts with documenting the organization's strategy and other necessary details such as where and how it operates. The process then cascades down to documenting discrete core competencies, business processes, and how the organization interacts with itself and with external parties such as customers, suppliers, and government entities.

Having documented the organization's strategy and structure, the architecture process then flows down into the discrete information technology components such as:

Organization charts, activities, and process flows of how the IT Organization operates
Organization cycles, periods and timing
Suppliers of technology hardware, software, and services
Applications and software inventories and diagrams
Interfaces between applications - that is: events, messages and data flows
Intranet, Extranet, Internet, eCommerce, EDI links with parties within and outside of the organization
Data classifications, Databases and supporting data models
Hardware, platforms, hosting: servers, network components and security devices and where they are kept
Local and wide area networks, Internet connectivity diagrams

Wherever possible, all of the above should be related explicitly to the organization's strategy, goals, and operations. The enterprise information security architecture will document the current state of the technical security components listed above, as well as an ideal-world desired future state (Reference Architecture) and finally a "Target" future state which is the result of engineering tradeoffs and compromises vs. the ideal. Essentially the result is a nested and interrelated set of models, usually managed and maintained with specialised software available on the market.

Such exhaustive mapping of IT dependencies has notable overlaps with both metadata in the general IT sense, and with the ITIL concept of the configuration management database. Maintaining the accuracy of such data can be a significant challenge.

Along with the models and diagrams goes a set of best practices aimed at securing adaptability, scalability, manageability etc. These systems engineering best practices are not unique to enterprise information security architecture but are essential to its success nonetheless. They involve such things as componentization, asynchronous communication between major components, standardization of key identifiers and so on.

Successful application of enterprise information security architecture requires appropriate positioning in the organization. The analogy of city-planning is often invoked in this connection, and is instructive.

An intermediate outcome of an architecture process is a comprehensive inventory of business security strategy, business security processes, organizational charts, technical security inventories, system and interface diagrams, and network topologies, and the explicit relationships between them. The inventories and diagrams are merely tools that support decision making. But this is not sufficient. It must be a living process.

The organization must design and implement a process that ensures continual movement from the current state to the future state. The future state will generally be a combination of one or more

Closing gaps that are present between the current organization strategy and the ability of the IT security dimensions to support it
Closing gaps that are present between the desired future organization strategy and the ability of the security dimensions to support it
Necessary upgrades and replacements that must be made to the IT security architecture based on supplier viability, age and performance of hardware and software, capacity issues, known or anticipated regulatory requirements, and other issues not driven explicitly by the organization's functional management.
On a regular basis, the current state and future state are redefined to account for evolution of the architecture, changes in organizational strategy, and purely external factors such as changes in technology and customer/vendor/government requirements, and changes to both internal and external threat landscapes over time.

High-level security architecture framework

Huxham Security Framework

Enterprise information security architecture frameworks is only a subset of enterprise architecture frameworks. If we had to simplify the conceptual abstraction of enterprise information security architecture within a generic framework, the picture on the right would be acceptable as a high-level conceptual security architecture framework.

Other open enterprise architecture frameworks are:

SABSA framework and methodology
The U.S. Department of Defense (DoD) Architecture Framework (DoDAF)
Extended Enterprise Architecture Framework (E2AF) from the Institute For Enterprise Architecture Developments.^[1]
Federal Enterprise Architecture of the United States Government (FEA)
Capgemini's Integrated Architecture Framework^[2]
The UK Ministry of Defence (MOD) Architecture Framework (MODAF)
NIH Enterprise Architecture Framework^[3]
Open Security Architecture^[4]
Information Assurance Enterprise Architectural Framework (IAEAF)
Service-Oriented Modeling Framework (SOMF)
The Open Group Architecture Framework (TOGAF)
Zachman Framework

Relationship to other IT disciplines

Enterprise information security architecture is a key component of the information security technology governance process at any organization of significant size. More and more companies are implementing a formal enterprise security architecture process to support the governance and management of IT.

However, as noted in the opening paragraph of this article it ideally relates more broadly to the practice of business optimization in that it addresses business security architecture, performance management and process security architecture as well. Enterprise Information Security Architecture is also related to IT security portfolio management and metadata in the enterprise IT sense.