Applying evidence of risk to support architectural design and change


There is an awful lot of material published on risk in general, risk analysis and management as well as the methods used to determine and classify risk.  Unlike vulnerability, which is more objective in evidence and assessment, risk is more subjective and therefore requires more effort in the gathering and development of the evidence used to support a decision. From an enterprise point of view decision makers will be subject to the risk vs cost vs benefit tradeoffs. When faced with these tradeoffs decision makers will have to choose from options that may cause harm or worse. Important factors in these choices include both the probability of a risk and whether its consequences would be negligible, moderate, or serious. So it is important that the criteria used in the evidence supporting the choices is sufficient for the right choice to be made as well as managing the consequences should the risk arise.

As always Wikipedia provides a suitable definition and further background to the topic:

In enterprise risk management, a risk is defined as a possible event or circumstance that can have negative influences on the enterprise in question. Its impact can be on the very existence, the resources (human and capital), the products and services, or the customers of the enterprise, as well as external impacts on society, markets, or the environment. [Wikipedia]

Certainly cyber threats pose events or circumstances that can have negative influences on the enterprise and security incidents and reports from security technology provide sufficient evidence that the risk of attack is constant. What is important is the requirement to ascertain what, within the enterprise, are the critical assets – services/systems and their availability, customer data, intellectual property etc., and conduct appropriate risk /threat assessment and evidence to show the risk can be mitigated or the threat determined.

If i refer back to the evidence model and the means to accumulate the required forms of evidence – for risk analysis and management – benefits from an evidence evaluation method and there are a number associated with risk:

  • FAIR (Factor Analysis of Information Risk) – Information Security
  • RiskIT – IT Risk
  • ISO 31000 – Risk Management General Principles and Guidelines
  • CRAMM – UK OGC General Risk Management Framework
  • ISO 27000 – ISO Series on Information Security Standards
  • NIST 800 – US standards for Computer Security
  • OCTAVE – CERT Strategic Information Risk Assessment

An evaluation method applies a level of control as well as quality to the output and also the reliability that the method has its own evidence of effectiveness.

I am going to use FAIR as the example method as the output gained can be applied to architectural decision making in respect to cyber security. In other words there is a risk to a critical system from an inside attack and in order to propose a change or security improvement plan evidence needs to show the vector and example evidence that the risk is highly probable.

FAIR Model Cyber Security Ontology
FAIR Model & Cyber Security Ontology

The model i have attached to this post shows the alignment between the recognition that the risk method is a valid evaluation method, the threat is determined as an Insider Threat and the vulnerable system being a Critical Business Application. The source of the security events associated with the threat are derived from Access Management log data analysed via anomaly analysis – unusual log in patterns by user for example – which also corresponds to an evidence source – metadata analysis. The purpose of the alignment of the evidence model to the risk method is to indicate that the method is a recognised and authoritative means to provide evidence and the source of the evidence is derived from a cyber defence capability. The data source for the Threat Event Frequency would be derived from the Log Analysis. Other criteria within the FAIR model would be derived form additional research or analysis. There are other factors to include that the data is stored and managed in a forensically ready manner, however the report output has justification nevertheless to support risk based decision making.

Cyber Security Ontology and Cyber Defence Ontology


First I am going to reference some work i found on the internet which offers some interesting insights into the various different views and approaches to developing ontologies for security and cyber security.

The first is a project form 2007 which provides a Cyber Security Ontology developed in OWL – Reference: A. Herzog, N. Shahmehri, C. Duma, ‘An Ontology of Information Security’, International Journal of Information Security and Privacy, 1(4):1-23, 2007. The paper is available here.

The second is a Seventh Framework research programme called PoSecCoPolicy and Security Configuration Management – and is contributing in some part to the Digital Agenda for Europe. One thing in particular which caught my attention is the paper called Security Ontology Definition, which describes in detail the ontologies consider within the project. There are also some interesting videos of the project.

It is interesting reading through the material produced by these projects as it shows the variety of different approaches taken to define and apply the domain of cyber security. It also highlights just how varied this domain is and how much needs to be formalised. The PoSecCo projects also describes a Security Decision Support System (SDSS) which would suggest that the models and data  are being used to infer some outcome to support a decision criteria.

Whilst each of the projects above have covered different areas of  security it may well be that from an ontological perspective that some consolidation of ideas and classifications are required to standardise the domain.  So, and it is just my opinion, there may be two or three key ontology models required – two if cyber defence is considered a subset of cyber security. The first being the enterprise architecture ontology to provide the context for all the entities that comprise the enterprise. The second is the security ontology covering what constitutes security through policy, compliance, threat, risk and vulnerability. The third is the defence ontology which covers the technologies, methods and capabilities to protect the enterprise. Each works in conjunction to provide a range of views to understand the challenges and also to provide sufficient situational awareness to combat the increasing threat. For more information on Situational Awareness there is an excellent website called Military Ontology which whilst specific to military defence has some very thought provoking material and resources. Finally there is a paper on the subject of Situational Awareness Ontology which is well worth reading and i hope to come back to this topic in the future.

Cyber Defence Ontology
Cyber Security Data Architecture