What is Multi-tenancy? How Secure is it?

Mar 2011

What is Multi-tenancy? How Secure is it?

Posted by Larry Bourgeois in Featured

Despite the evidence, many businesses still worry that storing data in the Cloud is not secure. That’s one of the main concerns our MSP partners hear when talking to their customers. For any company accustomed to traditional on-premise storage sitting safely behind a firewall (if configured and working properly), sending critical data to the cloud can sound like a HUGE security risk.  This fear that’s been hanging around since the earliest days of the cloud is especially pronounced for small businesses and for those less technically savvy.

When the first cloud applications and storage platforms appeared (Google Apps, Amazon EC2 and S3, etc.), serious businesses hesitated in adopting these new technologies. They were new and unknown and CIOs struggled with the question, “Are they secure?” Today, though, the cloud computing and storage market has matured and there are hundreds if not thousands of vendors offering a multitude of cloud application, storage, and computing services. Cloud security has been proven. There is really no greater risk storing data in the cloud than there is storing it internally.

One of the main differences between a locally managed computing environment and a cloud environment is the concept of multi-tenancy. Because data from different customers is stored side by side on the same servers, there is some lingering paranoia that “someone sharing my server can get at my data.” Multi-tenancy is not a new concept but it is an integral part of secure cloud-based applications and storage solutions. In fact, the largest cloud-based applications like Salesforce.com have employed multi-tenancy for years with great success.

What exactly is multi-tenancy? The following example should clarify:

Single Tenancy

If I own a house and am the only occupant then I have a lock on the main outside door to keep others out. This house could have many rooms, all secured by the one outside lock. If I share this house with others then I need to give everyone a key to the only lock so they can get into the house. Once inside the house, though, all rooms can be accessed by everyone. What if these people are not all known to me? I certainly would not want to give out too many keys as this is a security risk.


Now, what if I own an apartment building? There may still be a main lock on the outside of the building but inside there are many separate apartments, each with its own entrance protected by a unique lock. This prevents other tenants from entering an apartment that is not theirs. The owner of each individual apartment is the only one with a key to their lock. Only the owner of the apartment can get inside. Each apartment owner knows only about their own apartment and what is inside. They know nothing about the other apartments or their contents.

How does this translate to the cloud? A cloud-based application operates in much the same way. Access is controlled for each individual customer. When connected to the cloud application, the customer is not aware of anyone else using the same application. They see only their own data.

Nevertheless, the million dollar question still remains. Is it secure?  The answer is a definite YES and here is why.

Some applications provide security by controlling access with a username and password. Others use data encryption to secure the data. Data encryption requires installation of special software (referred to as a certificate or key) on the desktops of authorized users and is the method used by cloud-based backup applications like Asigra. Asigra is certified FIPS 140-2, which is the current US government standard for protecting data. This level of encryption (up to AES256) also meets all of today’s legal compliance requirements for HIPAA, Sarbanes-Oxley, and Gramm-Leach-Bliley.  Data from each customer is not only encrypted in-flight (to maintain security as it travels over the Internet to storage), it is also stored encrypted by the cloud backup application.

Each customer maintains total control over their unique encryption key or username/password combination (the lock and key to their apartment). Without this customer-specific encryption key or password information, no one can access their data – including storage personnel. This is the security provided by any multi-tenant cloud-based application.

Spice IT Email Post

I'm trying to understand if

I'm trying to understand if we can have customers backup solution be Hipaa compliant by using shared DSclient with multi tenancy turned on for the DS client. Reading through Hipaa's rules isn't the most straight forward. They are only using 2 servers, and rather than installing DSclient on their one of their servers, or adding a dsclient server for that purpose, it'd be great to put their backups in a shared dsclient, but i'm not sure if that'd present some hipaa issues.

Present HIPAA issues? You're

Present HIPAA issues? You're darn tootin' it will.

All the "multi tenant" option does, in DS-Client, is tag backup sets with a "Customer Name". If you allow all of the customers administrative access to the DS-Client they will quickly discover that they can mess with each others backup sets. Hardly secure, and hardly compliant with anything, HIPAA or anything else.

I suspect the "multi-tenant" option in DS-client is for providers willing to do all the backup set creation and maintenance, as well as on-demand restores, for customers who are knowingly storing information that is accessible by the admin at the provider site, and willing to do so because their data is NOT sensitive.

For more information

Get insights about cloud backup and recovery direct to your inbox every month.
Subscribe to our Newsletter
Stay connected to the latest data protection insights – subscribe to our blog.
Subscribe to our blog
Got questions for one of our recovery specialists?
Need Answers to your Questions?
Print this page
Email this page