Cloud Security: Encryption Is Key

Actually, this "shared responsibility" makes sense most of the time. The responsibility of cloud providers offering Platform as a Service (PaaS) and Infrastructure as a Service (IaaS) reasonably extends to the network and the infrastructure they provide. In fact, a typical agreement between you and your cloud provider will usually state that "…you acknowledge that you bear sole responsibility for adequate security…" So businesses hosting their applications in the cloud understand that they must share responsibility for ensuring the security of their data.

As cloud computing becomes increasingly more mainstream, it’s harder to distinguish the generic security issues that an IT manager needs to tackle, from those that are specific to cloud computing. Issues such as roles and responsibilities, secure application development, least privilege and many more apply equally well in traditional on-premise environments as they do in the cloud.

When an IT application is moved to a public cloud, all of the old security risks associated with it in the past still exist but, in addition, there are new risk vectors. Previously your servers and your data were physically protected within your server room. Now the "virtual servers" and "virtual storage devices" are accessible to you, the customer, via a browser; raising the concern that hackers may attempt to access the same. Here are some new risks scenarios to consider when migrating to the cloud:

1. Snapshotting your virtual storage by gaining access to your cloud console.
   A malicious user might gain access to your cloud console by stealing your credentials or by exploiting vulnerabilities in cloud access control. In any case, once inside your account, a "snapshot" of your virtual disks will allow an attacker to move a copy of your virtual storage to his or her preferred location and abuse the data stored on those virtual disks. This risk is in our opinion the most obvious reason to deploy data encryption in the cloud, but surprisingly enough, not all companies are aware of the threat and unknowingly expose their cloud-residing data to this significant risk.
2. Gaining access from a different server within the same account.
   Gaining access to sensitive data from a different virtual server inside the same account can be achieved by an attacker exploiting a vulnerability on that other server (such as a misconfiguration), or by one of your other cloud system administrators (a "malicious insider" from a different project in your own organization) using credentials or exploiting one of many known web application vulnerabilities to launch an attack on your virtual server. Unencrypted data can be exposed and stolen using this method.
3. The insider threat.
   Though this scenario gets mentioned a lot, it’s unlikely that a cloud provider employee will be involved in data theft. The more realistic scenario is an accidental incident related to an insider with physical access to the data center. One well-known example is the HealthNet case where 1.9 million customer records of HealthNet, a major US health insurer, were lost after its IT vendor misplaced nine server drives following a move to a new data center. According to HIPAA rules, disk-level encryption would have negated the incident impact.

The industry consensus is that encryption is an essential first step in achieving cloud computing security. An effective solution needs to meet four critical needs: High security, convenient management, robust performance and regulatory compliance. Data at rest is no longer between the proverbial "four walls" of the enterprise; the data owner is managing their own data with browsers and cloud APIs, and the concern is that a hacker can do the same. As such, cloud encryption is recognized as a basic building block of cloud security, though one difficult question has remained – where to store the encryption keys, since the keys cannot safely be stored in the cloud along with the data.

Protecting Content with Cloud Encryption and Key Management
Encryption technology is only as secure as the encryption keys. You have to keep your keys in a safe place. You need a cloud key management solution that can support encryption of your data and should supply the encryption keys for files, databases (whether the complete database or at the column, table, or tablespace level), or disks. This is actually the trickiest security question when implementing encryption in the cloud and requires thought and expertise. For example, database encryption keys are often kept in a database "wallet," which is often a file on your virtual disk. The concern is that hackers will attack the virtual disk in the cloud, and from there get access to the wallet, and through the wallet access the data.

Conclusion
Encrypting sensitive data in the cloud is an absolute must. Cloud security should include a blend of traditional security elements combined with new "cloud-adjusted" security technologies. Encryption should be a key part of your cloud security strategy due to the new cloud threat vectors (but also due to regulations such as the Patriot Act), and you should pay specific attention to key management.