Immutable Buckets: An Essential Data Protection Tool

If you need some serious protection on your data, creating an immutable bucket may be your best option. 

Many of us have heard of ‘immutable folders’ from usage of Windows Server, Unix or Linux. Simply stated, when a folder is immutable, users (including root or admin users) cannot change the contents in any way, whether by deleting, renaming or modifying. However, if the credentials of the user who set up the immutable folder are compromised, then the ‘immutable’ features of the folder can be changed.

What makes immutable folders different from permission management at a user level?  

With immutable buckets, specifically focusing on cloud storage, even if the admin user’s credentials are compromised, then the folder properties cannot be altered. This is an important consideration.

“If you steal somebody’s credentials [where permission management determines access level], you can destroy their data.  That’s the whole point of immutability.  You want to know that if you set up a bucket with a 7-year life, everything in that bucket is going to be there 7 years from now,” said David Friend, Co-founder of Carbonite and CEO of Wasabi, a Boston-based storage company.

How does it work? Is it too expensive for SMB budgets?

Cost and Benefits

At the time of writing, few service providers offer this immutable option for cloud storage.

“Microsoft has incorporated this into their Government Cloud product. You need it for legal reasons, like evidence in a court case. To date nobody else has that I am aware of.  I think eventually everyone will offer it because it’s such a no brainer,” said Friend. Cost is often a deciding factor when selecting a cloud storage provider and AWS is obviously the big player in this space. But, there are other options worth considering, if not as a primary solution then at least as a backup.

Wasabi will only cost $50,400 annually for a petabyte (1 million gigabytes) of storage whereas Amazon's S3 would cost $276,000. The same storage on comparable cloud storage services for Microsoft and Google would total $249,600 and $240,000, respectively.

This is simply an indication of publicly available pricing, and my opinions are unlikely to sway the storage market. Still, it’s a big pricing difference per petabyte. Working six times faster than AWS doesn’t hurt the Wasabi service either.

There are further benefits other than cost and speed. Let’s consider the WannaCry ransomware breach. It was ultimately caused by a vulnerability in older Windows operating systems, ones no longer supported by Microsoft. Even if the data breach was caused by a phishing attack, immutable buckets would have protected all valuable data.

 “If you have data that is stored in an immutable bucket it can’t be altered or deleted. So, if someone gets a virus that is attempting to take over your data and encrypt it, this is impossible. It will just produce an error message saying that the data can’t be altered. If all those people [impacted by WannaCry] had put their data in Wasabi and into an immutable bucket it would still be there in perfect condition because there’s no way the person or a piece of software could alter the content. If you have a data set that is a valuable asset, it is worth putting into an immutable bucket and immune to ransomware,” said Friend.

Read: Deep Web Monitoring And The Future Of Data Breach Detection

Setting Up An Immutable Folder

Setting up a ‘bucket’, or a scalable data storage area, can be done by selecting from a comprehensive set of options for storage, including immutability.

“There are rich set policies that you can choose when creating an immutable bucket (or folder).  For example, you can say “keep anything that I put into this folder for 5 years from the time I write the object.  But at 5 years and 1 day, automatically destroy the data”,” said Friend.  

“Keep in mind that you can set the immutable to expire whenever you want, so if you think you only want to keep the data for 1 year, there’s no reason you can’t.  Then you can decide whether you want to dump it or renew the immutability, or just leave it unprotected,” added Friend.

This does not mean that you cannot add new data to an immutable bucket.

“I use an immutable bucket for my family home videos and I add new stuff to the bucket on a regular basis.  The billing is daily based on how much is stored, just like an ordinary bucket,” said Friend.  

When Should Immutable Buckets Be Used?

Like most situations, companies need to perform a cost-benefit analysis and ask themselves if the value of the data is worth the investment.

“You’re going to end up paying for the storage of the data for the life of the immutability.  Therefore, the value of the data has to be great enough that you feel fine about paying to keep it.  For example, if I make a feature length film for $100 million and now I need to store the digital files for the next 20 years, the cost of the storage is so trivial compared with the cost of making the movie that I’d be fine with putting it in an immutable bucket knowing that it would now be immune to nearly any kind of deletion,” said Friend. 

Alternative Backup and Archival Solutions

Taking ransomware as an example once again, options that use an ‘air gap’ methodology (such as storing backup’s offsite on external hard drives or magnetic tape) will not be compromised by ransomware. But, if your original data is compromised, restoration of data could take a while, especially if tape is used. Backup failure is possible if backup integrity is not verified regularly. Restoring data from archives is also a time-consuming process. Both air gap and offsite solutions will ensure data integrity, restoration, and business continuity - assuming all goes well.

However, immediate access to data is not possible. Here immutable folders start to seem like a better solution since once the data is written, and the read-only applications perform their tasks uninterrupted, data cannot be corrupted.

Use cases could include big data or documents required for compliance (as it is easy to prove documents are unaltered).

“Analytics only requires that you read the data.  Frequently data sets used for analytics are extremely valuable, so it makes sense to store them in immutable buckets where they can’t be accidently or maliciously erased or overwritten,” said Friend.

This is worth noting. Once an administrator sets up an immutable bucket, he or she cannot delete or modify anything. Insider attacks may not be common, but disgruntled employees have one less way to destroy your data.

Another important point is that some data is not worth adding to immutable buckets.

“As for ecommerce, if you are going to create data and then delete it almost immediately, or if the data is of low value, you certainly wouldn’t want to bother with putting it into an immutable bucket,” advised Friend.  

Why not add a virus to the bucket? Even when a virus sneaks in, other files and folders in the bucket are unaffected.

In conclusion, immutable buckets have many advantages, even for a small business that would require mere terabytes of data storage. Worst case, a successful ransomware attack may result in data encryption on the local network. If the data is an immutable folder, all you need to worry about is restoring each workstation or server to an earlier state using either system images or a clean install. Paying to decrypt your data is not necessary.

When human error, cyber-attack and malicious insiders can no longer destroy your valuable data, surely this is a solution worth considering. Data is what keeps most companies in business, especially those in creative or design areas where intellectual property is key, so protection of that data is crucial. If you need to retain your data, an immutable bucket is certainly worth investigating. Otherwise, don’t bother. The choice is yours.