Symposium Summary: Security in the Cloud Panel
A panel summary by Ashish Kamra.
- Lorenzo D. Martino, College of Technology, Purdue University
- Keith Watson, CERIAS, Purdue University
- Dennis R. Moreau, Configuresoft Inc.
- Christoph Schuba, Sun Microsystems
The panel discussion included a 5-10 minute presentation from each of the panelists followed by a question and answer session with the audience.
The first presentation was from Lorenzo Martino. Lorenzo defined cloud computing as ‘computing on demand’ with the prominent manifestations being high-performance computing, and use of virtualization techniques. He also included other forms of pervasive computing such as body-nets, nano-sensors, intelligent energy grid, and so forth as cloud computing. The main security challenge identified by Lorenzo was coping with the complexity of the cloud environment due to the increasing scale of nodes. Another security issue identified by him was the decreasing knowledge of the locality of nodes as well as their trustworthiness with increasing scale of nodes. This in turn, introduces issues related to accountability and reliability. He outlined two main issues to be resolved in the context of a cloud computing environment. First issue is to strike the right balance between network security and end-point security. Second issue is the lack of clarity on attack/risk/trust models in a cloud environment.
According to Keith, the best way to explain cloud computing to a layman is to think of cloud computing services as utilities such as heat and electricity that we use and pay for as needed. His main security concern in the cloud environment was on the legal ramifications of the locality of data. For example, a company in the European Union (EU) might want to use Amazon cloud services. But it may not be legal if the data at the backend is stored in United States (US) as the data privacy laws of EU and US differ. Another concern raised by Keith was the lack of standards among cloud computing services. Because of insufficient standardization, verification of cloud services for compliance with regulations is very difficult. Finally, according to Keith, despite all the current security challenges in an cloud environment, the cloud will ultimately be widely adopted due to the lower costs associated with it.
Christoph reiterated that cloud services will become mainstream because of theirs flexibility (don’t have to worry about under-provisioning or over provisioning of resources) and lower total cost of ownership. But the key point to understand is that the cloud computing paradigm is not for everyone and everything as cloud computing means different things to different people based on their requirements. Citing the example of grid computing, Christoph highlighted the fact that there is inherent lack of demand for security in the cloud. For example in grid computing, more than 95% of the customers opt out of the grid security services due to various reasons. According to Christoph, the main challenge in cloud security is that increased abstraction and complexity of cloud computing technology introduces potential security problems as there are many unknown failure modes and unfamiliar tools and processes. He also added that the cloud security mechanisms are not unlike traditional security mechanisms, but they must be applied to all components in the cloud architecture.
Security issues arising out of the sheer complexity of the cloud environment were also raised by Dennis. There are layers of abstraction in the cloud environment with multiple layers of technologies each with their own configuration parameters, vulnerabilities and attack surface. There is also lots of resource sharing, and the hosting environment is more tightly coupled. All such factors make articulating sound security policies for such environment a potential nightmare. The questions that seem most difficult to answer in a cloud environment are how to achieve compliance, how is the trust shared across different regulatory domains and how much of the resources are shared or coupled. There is an inherent lack of visibility inside a cloud environment. A potential solution is to expose configuration visibility in to the cloud for performing root cause analysis of problems. Also, maintaining smaller virtualization kernels as close as possible to the hardware so that they can be more trustworthy and verifiable will help address some of the security risks.
Question and Answer Session with the Audience
A recurring theme during the question/answer session was related to trust management in the cloud environment. The first question was that how do ‘trust anchors’ in the traditional computing environment apply to the cloud? Dennis replied that the same trust anchors such as TPM etc. apply but the interplay between them is different in the cloud. There are some efforts to create virtual TPMs so that each virtual operating system gets its own vie of trust. But how that affects integrity is still being worked upon. Keith however was more skeptical of the ongoing work in trust anchors solutions because of the complexity of the provider stacks. Another question related to trust was that why should a normal user trust his private information to a cloud provider. Dennis replied that users will be driven to use the cloud services based on cost, and use such utilities because of the savings passed to them. The onus is thus on the cloud service providers to take of security and privacy issues. Christoph added that with respect to trust, the cloud is no different than other computing paradigms such as web services or grid computing. Companies providing cloud services will need to answer trust issues for their own customers. The next question was on the legal/compliance hang-ups of the cloud with respect to location of the data. Specifically, there were concerns on the chain of custody data and accountability. Dennis replied that the legal and compliance requirements haven’t and can’t (yet) keep up with change in technology. But this also provides an incentive for the providers to differentiate themselves from the rest on the basis of auditing and legal support offered with their services. Christoph suggested that such concerns should be addressed in the Service Level Agreements (SLAs) which then become binding on the service providers. Lorenzo pointed out that coming up with new regulations for the cloud environment will be a very difficult task as even the current regulations such as HIPPA have gray areas.
Another interesting question was whether outsourcing IT services to a cloud provider is a win in security because of the expertise at the cloud provider? Dennis agreed that at least with respect to managing configuration complexity, it is better off for the organizations to outsource their services to a cloud provider. Christoph pointed out that availability as a security issue is a big win in the cloud environment as it almost comes for “free” with any cloud provider. But maintaining in-house 24x7 availability is a very resource consuming task for most organizations.
There was a comment that there is a perception among customers that if the data is outside the organization, it is not safe. In reply to this comment, Christoph reiterated that cloud computing is not for everyone. If data is sensitive such that it cannot be outsourced then probably cloud computing is not the right answer. Strong SLAs can help mitigate many concerns, but still cloud computing may not be for everyone. Some related queries were on the safety of applications and on the enhanced insider threat concerns in the cloud environment. Dennis echoed similar concerns and mentioned that people in working in cloud environment are audited very carefully as they have a lot of leverage. Christoph added that there are techniques beyond auditing to mitigate insider threats such as application firewalls, no sniffing, scanning the data out of the hosted images, intrusion detection of hosted images, and so forth. Such controls can be articulated in the SLAs as well. Dennis gave an example that ESX with OVF-I can associate security controls in the models for each hosted instance which also puts less burden on the application developers.
Next question was whether it is possible to but keep applications local but still get the benefits of cloud security? Dennis replied that it is possible but the organizations need to be careful about applying security requirements consistently when using cloud only for some things. It is also important to understand the regulations and the risks involved before doing so.
To the query as to what data can be put into cloud without worries about security (public data), Keith replied that organizations needs to have a classification system in place to figure out what is acceptable for public access.
Many questions that followed at this stage were related to general cloud computing requirements such as on sustainability of cloud computing, applications of cloud computing, distinction between a hosting provider and cloud provider, and so forth. This was expected as the audience primarily consisted of people from academia who are yet to come to grips with the aggressive adoption of cloud services in the industry.
Finally, at the end there were two very interesting questions related to cloud security. First question was with regard to integrity of data in a cloud environment; how can the data integrity be preserved and also legally proved in a cloud environment? Christoph pointed out that data integrity is guaranteed as part of the SLAs. Dennis pointed out that many of the distributed systems concepts such as 2-phase commit protocol are applicable to the cloud environment. Integrity issues may be temporal as replication of data may not be immediate. But surely long term integrity of data is preserved. The second comment was that whether the clouds are now a more appealing target for attackers in the sense that does it increases reward over risk? Dennis agreed that putting all our eggs in one basket is a big risk, and also that such convergence will lead to a greater attack surface and will give much greater leverage to the attackers. But the underlying premise is that the benefits of the cloud technology are amazing, so we have to work towards mitigating the associated risks.