In our opinion security is a process, not a destination to arrive at. Good security design and implementation takes time, patience and hard work to achieve and maintain. You should always start with the basics by creating an architecture or overall design. As security and privacy is always one of the most important subjects within IT the importance of good security and privacy keeps growing. This since companies are more and more depending on IT. Also the influence of IT goes deeper into our lives. Next to safety, security and privacy become more important when we realize the potential risks that come with new IT technologies.

This reference architecture is created to improve security and privacy designs in general. In our opinion it is time to stop reinventing the wheel when it comes down to creating architectures and designs for security and privacy solutions.

This reference architecture is not just another security book. Since libraries and book stores are filled with decent books on security and privacy we wanted to create a book that is all about reuse. There are two main pillars that drive this publication:

  • Enabling reuse for companies of all sizes worldwide in order to design security and privacy solutions.

  • Creating an open reference architecture that enables collaboration and improvement in an easy way.

This reference architecture aims to enable you to create better and faster security and privacy solutions by reusing the content provided in this publication. And to encourage collaboration on this publication we created this reference architecture under an open license. We have chosen to use the Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0) license. We know you like credit if you contribute to a publication. If you contribute you are of course be mentioned in all updates of this publication that follow. And since it is a true open license, your rights regarding this publication are no different than ours or other contributors.

To summarize this publication is an open reference architecture aiming to help you to design better and more secure systems in less time and with less cost.

Why another reference architecture

Open publications for IT security and privacy are still rare. Despite the great work of the OWASP foundation many IT security  organizations are not that open.

When you create a new medicine that can and save millions of human lives it is not only ethical but also a moral right that people can use it. Science is there so we can build on each other’s ideas.

This means progress for all. We all win. Within the field of software coding Open Source (OSS/FOSS) is becoming the new de facto model. Why create something anew that you already have created?

Within the field of security consultancy and security architecture Open is not (yet) the de facto standard. Of course some key assets as passwords or personal data should never be accessible. But creating security architectures and security designs is by many positioned as an art. That is strange of course. If you need a new color on your wall you do not call an artist, but a painter. The same goes for security: go for a proven open solution that has been used before. All solutions are of course mostly always context specific. No organization is the same. But that does not mean that every aspect for your architecture, and design should be new. We all use standard solutions where possible. Reuse of architecture and design is rare at the least. This reference architecture is aimed at enabling reuse of parts that are needed in every security architecture and design. That means less art, but the puzzle that remains is more interesting to solve. Since this is the real context related problem!

Availability of good references with solid reusable information makes creating security architectures easier and more fun. Easier because when you have a good security reference architecture you do not need various books to find out what already good proven parts for your architecture could be. More fun because you have more time to figure out what the best solution for your unique security challenge is. And we see thinking and resolving real security issues as fun. Minimizing security and privacy risks  is always unique and context depended. E.g. unique stakeholders, different security control system (organization) and a different way of dealing with risks.

Why security and privacy

Privacy is getting more and more important. New technologies make our lives better but put our freedom and privacy under pressure. Terrorist and (cyber) criminals can be more easily detected by analyzing large amounts of data. Also ‘diseases’ can be better cured using more data of more people.

Currently great improvements come at a large price: Big data analytics systems are going over your user data and user data traces (e.g. mouse movements in web pages, location data) multiple times a day. Companies know better what you need, think and eat tomorrow than you. Your location is continuously being tracked, due to all the communication devices you use. Using public transport cannot be done anonymously anymore while cars are full of track and tracing technology.

When privacy is designed first just as security we should have less concern on security and privacy hacks. Also if more IT designs are open and published under an open license, chances of mistakes in architecture and design are lowered. Partly due to pressure of openness but also since more experts can contribute to lower security and privacy risks concerned with public or private systems. Of course: Transparency of governmental systems is still a very long journey. Companies however see advantages of open solutions more and more. Using open solutions, open business models and open source software for IT. A large number of companies exist that benefit from using open designs along with open source software.

Many new technology companies are successful due to the fact that they promote open (FOSS) solutions. E.g. Companies like Automattic (WordPress) ( or Acquia (Drupal) ( are all very successful due to a true GPL OSS policy. But also many security companies have created a sustainable business by creating a real FOSS security product. E.g. the people behind created a great product and business using an AGPL License for its core product.

We know that privacy can be regarded as something totally different than security. This is why we had some resistance with combining a reference architecture for security with privacy ‘things’. But our research showed that:

  • Privacy has many relations with security. Many problems are similar.

  • Privacy aspects are by far not yet taken serious into architectures and design the way they should be. It took decades and billion dollar (or euro) campaigns before security aspects were taken more seriously into account. And yet security is still difficult due the fact that doing it right gives no direct business value. Doing it wrong always means a true disaster for your business. And the same goes for privacy.

  • Security and privacy are interrelated. Without security there is no privacy! Never.

Since privacy and security are very much interrelated both aspects are outlined in this reference architecture.

Advantage of using this reference architecture

A good reference architecture saves time in many ways:

  • You can create a solution architecture based on it for your specific situation.

  • It enables you to speed up the process of creating a specific solution.

  • It contains valuable content and general background information which can be used, reused or referred to.

Information security architecture is an abstraction of a design that identifies and describes where and how security controls are used. It also identifies and describes the location and sensitivity of both user and application data.

This open reference security architecture aims to help you create your context specific architecture faster and with higher quality.

This reference architecture  is designed to assist and guide architects, security designers and developers to make better decisions and to reuse quality architecture knowledge regarding cyber security aspects.

The purpose of this document is to reuse good security principles, requirements and design patterns to save precious time and budgets. Since security by obscurity is in general not a good practice, we also provide a list of OSS security software products.

Systems built with tough privacy rules don’t always guarantee that information including valuable privacy content is secure. Since perfect security does not exist, even a highly secured system always contains risks concerning privacy.

Who should use this reference architecture

The target audience for this reference architecture are security experts and companies who can see the benefit of reuse and using open source security building blocks. Specifically all business owners, security architects, security designers, asset owners, software developers, system administrators and (end) users who have a role in reducing security risks.

Scope of this reference architecture

Not all aspects of security and privacy can and should be outlined in a reference architecture. This reference architecture is not about teaching what security and privacy is. This reference architecture is not about providing detailed technical information on solutions that come across.

This reference architecture is also not a lecture book on how to design the perfect security solution architecture. There are many resources (books, courses, foundations) that teach you the benefits of creating an (enterprise) architecture and how you can embed architecture into your agile way of working. Be aware of course that an agile way of creating new products, systems or software gives some tension regarding security and privacy aspects. It is difficult to add security and privacy aspects at a later point if not done correctly from the start. So use new trends whenever possible. But if you were to design ‘A human mission to Mars’ important aspects like security and safety cannot wait till later.

Since you are reading this reference architecture, we assume you are already aware of the complex field of security and privacy. Very detailed books, papers and studies exist for learning what security and privacy really is. So this reference architecture does not provide in depth detailed background information on all security and privacy aspects. Not from an organization point of view and certainly not from an IT point of view.

The scope and aim of this open security architecture is to enable you to create better and faster security solution architectures and designs using open reusable building blocks and standards. Within the scope of this reference architecture are:

  • Security solution aspects, e.g. models, that must, should or could be reused in a security or privacy solution architecture.

  • Information that can be reused in an easy way in your context specific security/privacy solutions. E.g. security and privacy principles.

  • Criteria aspects you can reuse when selecting security solutions for your solution architecture.

  • (Sample) Security/Privacy Solution Building Blocks that are created for reuse. These SBB’s serve as example to give you a more in depth overview of possibilities you are maybe not familiar with.

Within this reference architecture we focus on the following subjects that you should face when creating a security or privacy solution:

  • Principles: We provide a reusable list of security and privacy principles. Since this open security and privacy reference architecture has an Open approach we encourage you to add your principles to the open data source we created to help others from reinventing the wheel again and by doing so they save time.

  • Solution Building Blocks: We provide a list of solid reusable security and privacy tools and building blocks. Of course all tools and building blocks are open source. One core principle is that good security should be open. Within this eBook a detailed outline is given on the question if extra risks factors are involved in using open source solutions.

  • Reusable architecture and design patterns for security and privacy problems. During the architecture and design phase threat models are constructed. This document contains generic threat models, since these are reusable. That can be improved when the model is made publicly available.


Many aspects regarding security and privacy our not in scope of this reference architecture. The clear and only focus is on providing open content that makes creating solutions for common security and privacy challenges simpler.

What about security patterns?

In system design, coding and architecture you should strive to reuse predefined patterns. A pattern is a reusable way to solve a standardized problem. This can be in software code, design or an organization problem.

Good patterns within the security and privacy field are rare. We did research on available reusable patterns that can help creating security or privacy solutions faster. Our findings are:

  • Good described reusable security and privacy solution patterns are rare.

  • Reusable architecture and design patterns for security and privacy problems are scarce. Most relevant patterns are vendor specific, so are targeted to the solution building block reuse aspects.

  • Use of patterns can increase complexity. Understanding pattern language  and semantics is important before being able to judge if your chosen pattern applies to the unique challenge that must be solved. Since libraries are written on generic problem solving methods (note: the golden book is still not found) some precaution using patterns is very healthy!

  • Developing usable patterns (also in a collaborative way) for a reference architecture takes up a lot of time while the practical use (or reuse) in a solution architecture is often limited.

We hope good developed patterns for dealing with typical security and privacy problems are developed in future. Also we hope these patterns are developed in an open collaborative way and published under an open license so everyone can benefit and participate. Some good attempts have been done, so maybe time for a new OWASP project to give it a boost.

We think that when you develop a good solution architecture in which you describe your problem clearly, this solution architecture enables you to use or create a library of reusable solution patterns for security and privacy needs. One import constraint is that your solution architecture should be published under an open license somewhere on the internet. In this way every organization, security designer can benefit. Some governments already publish their architecture documents under an open license (CC) on the internet. This is a great way for governments to align better with society. Everyone can see how complex digital information systems become and can suggest improvements. Detailed configuration information is not needed to judge the risks of security or privacy vulnerabilities. Companies worldwide are still very anxious to benefit from the possibilities that a more open transparent company (using open licensing) can give.

How this reference architecture is structured

This reference architecture is built around information that helps you creating security or privacy solution architectures.


It is also built to give you reusable information in an easy to find way. The next chapter (‘Security Models‘) deals with models, attack vectors and information that helps you create the threat model you need to develop in your solution architecture.

The chapter  ’Security and Privacy Principles‘  presents solid security and privacy principles. Focus is on use and reuse.  The chapter ‘Using Open Source for security and privacy protection’ outlines facts to demystify common fads regarding use of Open Source and security and privacy products. This chapter outlines how to evaluate OSS Solution Building Blocks for security and privacy applications. The chapter ‘Open Source Security and Privacy products’ presents a list of great OSS solutions available to be incorporated into your security or privacy solution or just to take a look at.

The appendixes will give you information on reference used, as well as information on how you can contribute with the next version of this reference architecture.