Managing the security of hybrid clouds

 Gavin Payne is a principal architect for Coeo, a SQL Server and Azure professional services company, and a Microsoft Certified Architect and Microsoft Certified Master. His role is to guide and lead organisations through data platform transformation and cloud adoption programmes.

Hybrid clouds provide a single IT environment that seamlessly integrate on and off premises services. One of their many benefits is providing single security and network access models for users and services, whether they’re on-premises or in the cloud. However, this can be difficult when two different owners of IT services meet for the first time.


Two silos don’t make a hybrid cloud

Only when an organisation joins together its on and off premises IT services does it have a hybrid cloud. More specifically, unless their authentication and network services work together then at best the organisation has two loosely coupled environments, at worst it has two silos that can’t communicate. When users, applications and services can use a single set of credentials and domain name records, then the hybrid cloud has arrived.

We do it, they do it, we both do it – or even worse neither of us do it

In the on-premises world, there is often only one security manual for everyone to follow. A single guide to who manages what, how and using what. Whether it’s user account management, the deployment of firewall rules or achieving of industry compliance  - it only needs to be done once. 

In a hybrid cloud, most things should still only need to be done once. But for some reasons, some things might need to be done twice. The worst scenario is when someone knows something needs doing – and thinks the cloud provider is doing it for them. Understanding how an organisation’s security expectations can be transparently deployed to both environments needs planning. 

What needs to be done?  Is it a once per site or once per hybrid cloud setting? Who’s going to do it?  If it’s in the cloud, do we know how to make the change? At short notice? Will compliance checks remember to start looking in two places? 

Recommendation one  - Define what needs to be done to keep everything secure and make sure you know who’s responsible for doing it.


A hybrid cloud with boundaries

While hybrid clouds let on-premises services seamlessly use cloud services – for example a database server backing up its databases to Azure file storage – one of the reasons for them is to keep sensitive data out of the cloud. Retaining a small number of secure on-premises servers is a must for some businesses yet the hybrid cloud model still lets them adopt the latest fully managed public cloud services. 

However, a hybrid cloud can be too integrated and not respect security, political or organisational boundaries. Not only might technical security boundaries need to be put in place (network admins have used DMZs to do this for years) but also operational security boundaries. When organisations have sensitive systems audited by external parties, they need to make sure their footprint hasn’t crept into the cloud by stealth – and ended up interacting by services that a third party somewhere somehow influences or manages. Using cloud based backup systems, authentication services and operational management tools are good examples of quick hybrid cloud wins – but also compliance nightmares. 

Recommendation two – keep the footprint of any sensitive systems as small as possible. Use technical and operational boundaries to stop them from slowing down the pace of cloud service adoption.



Skip to main content