Layers in IT security

A layered security strategy is a good practice to enhance the overall IT security in companies.

The essence of layered security is to implement security measures in different parts of the IT infrastructure.

This approach is comparable with physical security. If a burglar wants to steal money from your house, he has to go over the fence in the garden, than through an closed front door with locks, then he has to find the safe with the money, he has to break it open, get the money and leave the premises. All of this must be done without being seen or heard, and he must not be noticed by anyone during all these steps.

It is obvious why this works so well in daily practice:

  • Many barriers must be crossed (fence, door, safe);
  • Opening every barrier takes different technical skills (climbing over the fence, lockpicking a door with a mechanical lock, opening a safe with a digital lock);
  • The burglar is slowed down by every barrier he tempts to cross, which increased the possibility of detection;
  • The burglar doesn't know in advance how many barriers he has to cross, how much time each barrier takes, and which knowledge is needed for every barrier, which is very demotivating;
  • The chance of getting caught is present in every step;
  • When one barrier is crossed, the security of all other barriers are still intact.

It will be obvious for everyone that this works much better than having one big expensive safe somewhere in a dark forest without taking further measurements.

In IT security this principle works the same (layered security). Instead of having one big firewall and let all your security depend on it, it is better to add several layers. Preferably these layers make use of several different technologies, which makes it harder for hackers to break through all barriers. They will need much knowledge for this.

Every layer can be utilized with an IDS (Intrusion Detection System) or some other measurement to detect break-ins (increase the chance of getting caught). On top of this, more layers introduce uncertainty for the hacker: How many barriers must be passed to get to the data, and how long will this take (demotivation).

If one layer is passed unnoticed, or if one security layer contains a vulnerability (caused by a bug or a mistake in the configuration), the total security is still intact (although with less layers).

A disadvantage of the use of layered security is that the complexity of system management increases. Every security layer must be managed, and administrators must have knowledge about all used technologies.

But as always with security: It costs money and causes inconvenience. But is it always better than having insufficient security.

Some examples of layered security can be found here and here.

This entry was posted on Friday 18 May 2007

Earlier articles

The cloud is as insecure as its configuration

Infrastructure as code

My Book

DevOps for infrastructure

Infrastructure as a Service (IaaS)

(Hyper) Converged Infrastructure

Object storage

Software Defined Networking (SDN) and Network Function Virtualization (NFV)

Software Defined Storage (SDS)

What's the point of using Docker containers?

Identity and Access Management

Using user profiles to determine infrastructure load

Public wireless networks

Supercomputer architecture

Desktop virtualization

Stakeholder management

x86 platform architecture

Midrange systems architecture

Mainframe Architecture

Software Defined Data Center - SDDC

The Virtualization Model

What are concurrent users?

Performance and availability monitoring in levels

UX/UI has no business rules

Technical debt: a time related issue

Solution shaping workshops

Architecture life cycle

Project managers and architects

Using ArchiMate for describing infrastructures

Kruchten’s 4+1 views for solution architecture

The SEI stack of solution architecture frameworks

TOGAF and infrastructure architecture

The Zachman framework

An introduction to architecture frameworks

How to handle a Distributed Denial of Service (DDoS) attack

Architecture Principles

Views and viewpoints explained

Stakeholders and their concerns

Skills of a solution architect architect

Solution architects versus enterprise architects

Definition of IT Architecture

What is Big Data?

How to make your IT "Greener"

What is Cloud computing and IaaS?

Purchasing of IT infrastructure technologies and services

IDS/IPS systems

IP Protocol (IPv4) classes and subnets

Infrastructure Architecture - Course materials

Introduction to Bring Your Own Device (BYOD)

IT Infrastructure Architecture model

Fire prevention in the datacenter

Where to build your datacenter

Availability - Fall-back, hot site, warm site

Reliabilty of infrastructure components

Human factors in availability of systems

Business Continuity Management (BCM) and Disaster Recovery Plan (DRP)

Performance - Design for use

Performance concepts - Load balancing

Performance concepts - Scaling

Performance concept - Caching

Perceived performance

Ethical hacking

The first computers

Open group ITAC /Open CA Certification

Sjaak Laan

Recommended links

Ruth Malan
Gaudi site
Esther Barthel's site on virtualization
Eltjo Poort's site on architecture


XML: RSS Feed 
XML: Atom Feed 


The postings on this site are my opinions and do not necessarily represent CGI’s strategies, views or opinions.


Copyright Sjaak Laan