While cloud security remains a top concern in the enterprise, public clouds are likely to be more secure than your private computing setup. This might seem counter-intuitive, but cloud service providers have a leverage of scale that allows them to spend much more on security tools than any large enterprise, while the cost of that security is diluted across millions of users to fractions of a cent.
That doesn't mean enterprises can hand over all responsibility for data security to their cloud provider. There are still many basic security steps companies need to take, starting with authentication. While this applies to all users, it's particularly critical for sysadmins. A password compromise on their mobiles could be the equivalent of handing over the corporate master keys. For the admin, multi-factor authentication practices are critical for secure operations. Adding biometrics using smartphones is the latest wave in the second or third part of that authentication; there are a lot of creative strategies!
Beyond guarding access to cloud data, what about securing the data itself? We’ve heard of major data exposures occurring when a set of instances are deleted, but the corresponding data isn’t. After a while, these files get loose and can lead to some interesting reading. This is pure carelessness on the part of the data owner.
There are two answers to this issue. For larger cloud setups, I recommend a cloud data manager that tracks all data and spots orphan files. That should stop the wandering buckets, but what about the case when a hacker gets in, by whatever means, and can reach useful, current data? The answer, simply, is good encryption.
Encryption is a bit more involved than using PKZIP on a directory. AES-256 encryption or better is essential. Key management is crucial; having one admin with the key is a disaster waiting to happen, while writing down on a sticky note is going to the opposite extreme. One option offered by cloud providers is drive-based encryption, but this fails on two counts. First, drive-based encryption usually has only a few keys to select from and, guess what, hackers can readily access a list on the internet. Second, the data has to be decrypted by the network storage device to which the drive is attached. It’s then re-encrypted (or not) as it’s sent to the requesting server. There are lots of security holes in that process.
End-to-end encryption is far better, where encryption is done with a key kept in the server. This stops downstream security vulnerabilities from being an issue while also adding protection from packet sniffing.
Data sprawl is easy to create with clouds, but opens up another security risk, especially if a great deal of cloud management is decentralized to departmental computing or even users. Cloud data management tools address this much better than written policies. It’s also worthwhile considering adding global deduplication to the storage management mix. This reduces the exposure footprint considerably.
Finally, the whole question of how to backup data is in flux today. Traditional backup and disaster recovery has moved from in-house tape and disk methods to the cloud as the preferred storage medium. The question now is whether a formal backup process is the proper strategy, as opposed to snapshot or continuous backup systems. The snapshot approach is growing, due to the value of small recovery windows and limited data loss exposure, but there may be risks from not having separate backup copies, perhaps stored in different clouds.
On the next pages, I take a closer look at ways companies can protect their data when using the public cloud.