Cloud computing users face problems including loss of control over data, difficulties proving compliance, and additional legal risks as data moves from one legal jurisdiction to another, according to a assessement of cloud computing risks from the European Network and Information Security Agency (ENISA).
The agency highlighted those problems as having the most serious consequences and being among the most likely for companies using cloud computing services, according to ENISA.
ENISA examined the assets that companies put at risk when they turn to cloud computing, including customer data and their own reputation; the vulnerabilities that exist in cloud computing systems; the risks to which those vulnerabilities expose businesses, and the probabilities that those risks will occur.
At the same time, service level agreements (SLAs) may not include those services. The result is a gap in defenses, ENISA said in the report.
Compliance could also prove to be a big problem if the provider can't offer the right levels of certification or the certification scheme hasn't been adapted for cloud services, the report said.
One of the advantages of cloud services is that data can be stored in multiple locations, which could save the day in the event of an incident in one of the data centers. However, it could also be a big risk if the data centers are located in countries with a shaky legal system, according to the report.
Other areas of concern are vendor lock-in, failure of mechanisms separating different companies, management interfaces that get accessed by hackers, data not deleted properly and malicious insiders.
To minimize these risks the report proposes a list of questions that a company needs to ask potential cloud providers.
For example, what guarantees does the provider offer that customer resources are fully isolated, what security education program does it run for staff, what measures are taken to ensure third-party service levels are met, and so on.
In the end a good contract can lessen the risks, according to the report. Companies should especially pay attention to their rights and obligations related to data transfers, access to data by law enforcement and notifications of breaches in security, it said.
ENISA's report isn't all doom and gloom, though. Using cloud computing services can result in more robust, scalable and cost-effective defenses against certain kinds of attack, according to the report.
For example, the ability to dynamically allocate resources could provide better protection against DDoS (distributed denial-of-service) attacks, ENISA said.