The increase in workforce mobility, the adoption of virtualisation and cloud computing and the growing acceptance of "Bring Your Own Device" in the enterprise are all forces contributing to the erosion of the established enterprise security model.As the smartphone and tablet, running iOS, Android and possibly soon Windows Phone7, become tools of choice for the mobile corporate employee; data and systems are increasingly mobile, less centrally managed and traditional security architecture becomes more fragmented. These same factors are also contributing to the steady erosion of the attractive mono-culture of Microsoft Windows as an everyday operating system, for so long the dominant enterprise platform.The mono-culture was attractive for two important reasons; firstly it is easier to manage and protect a single platform through a single management infrastructure. This meant that the establishment of a "standard operating environment" was simpler and the maintenance of that environment from a configuration and patching point of view was also relatively unified.Secondly, monocultures are also attractive to criminals and others of dubious intent for a number of reasons. Most obvious is the return on investment, malware developed for a dominant platform has the highest possible financial return as the attack surface is exponentially larger. Also with regard to more targeted attacks the initial footprinting of the victim is simplified when you can make educated assumptions about operating systems and browsers that will be prevalent within the target organisation and repackage "off-the-shelf" malware toolkits.So what of the future? Server virtualisation is already firmly entrenched and many enterprises are well on the way to the establishment of private cloudswithin their own datacentres.Enterprises and small businesses alike see the commercial and operational benefits offered by the public cloud model, whether that be through the Software as a Service model of Google Apps or companies like Salesforce.com or the Infrastructure as a Service offering of the likes of Amazon. Desktop virtualisation is also beginning to gain ground as technology from the likes of VMware and Citrix is proven to be up to the task. Data storageis increasingly centralised and mobile at the same time because the centralisation is happening with private, hybrid or public clouds.The means of accessing our desktop operating systems, our corporate resources and data is fragmenting, there may well be no dominant endpoint platform within the next five years.Enterprise security planning will focus on a new monoculture for manageability and scalability and criminals will follow the money, seeking the biggest bang for the buck for the lowest investment cost. The new monoculture will be in the clouds, public and private.Enterprises need to start planning now to deploy tools and technologies to ensure the clouds they build are as secure on the inside as their traditional datacentres used to be on the outside. Public cloud customers need to begin considering host-proof security, effectively segmenting their data and systems away from their untrusted neighbours within the same datacentre and even multi-departmental private clouds need to ensure that their Chinese Walls remain in place in this new environment. Datacentres will become the new criminal frontier and the potential consequences of compromise could be as devastating\u00a0 as the criminal rewards are tempting.