Cloud storage security: comparative study
Today the use of cloud-based storages is becoming more and more popular. Indeed, why should you care about buying and configuring the server, ensuring its physical and virtual stability, if instead you can actually afford to buy any number of virtual machines and change their quantity depending on the influx of visitors to your resource. The article by Anna Andreeva, security testing engineer.
Cloud providers allow you to get fast access to all the necessary equipment for virtual work both small sized and enterprise applications with complex business logic and numerous services. In addition, development process of cloud web application does not differ much from applications written in a conventional computer. Definitely, it is convenient. Especially if you must run the project in the short term and it’s difficult to predict the number of users. In such cases, cloud “infrastructure as a service» (IaaS) is convenient which offered by a dozen of eminent providers.
However, how safe it actually is to store your data in the cloud? After all, if the server is not in the next room and the door is locked with a key, someone definitely has access to it – at least network provider staff.
How safe is the transmission of data from client to the cloud storage? And back? That’s what two most popular providers offering cloud infrastructure are saying about their safety.
Perhaps, the most famous provider of cloud infrastructure is Amazon EC2, which has long been a leader among competitors.
What the customer gets when entrusts the product to Amazon?
- Multilevel security. Security mechanisms implemented at several levels: for host operating systems, virtual instances and virtual guest OS, as well as firewalls and API calls.
- Hypervisor. Amazon EC2 uses a modified version of the Xen hypervisor, which can significantly improve the performance of virtual machines through paravirtualization. And access to the CPU implemented with separate privileges: Host OS has the highest level (0), the guest OS – level 1, and the applications have the least privileges (level 3).
- Isolation instances. Multiple guests can be deployed on one physical machine. Although instances do not have direct access to the physical disk, they are given the virtual data storages. In order data from different applications do not influence each other in the case of disk space liberation, information from each of the storage units is automatically deleted (the value is set as zero). Memory is not returned to the pool of free memory until the reset process completes.
- Security of the host OS. Multifactorial authentication system is envisaged for administrative access to the hosts management. If an employee no longer needs in such access his account canceles.
- Host OS security. Support of security here lies entirely on the development team, as provider does not have access to both – the instances and guest operating systems that are installed on them. It is in fact a strong side in the context of application security (provider can not get the customer’s data) but also creates potential vulnerabilities for attacks. Configuration errors can potentially give attacker access to applications, data, and even entire virtual machine.
- Firewall. By default, all firewall’s ports are closed. This means that the customer himself must vividly open the ports for incoming traffic. Amazon provides the ability to split the levels of access groups (Security Groups).
- API access. API calls to start or interrupt instances, change firewall settings and other functions signed by a secret key (Amazon Secret Access Key). Access to API is impossible without it. In addition, the API calls are encrypted using kriptogafical SSL protocol.
Read the second part here.
The artilce Cloud Storage Security: AWS Vs.Azure by Anna Andreeva was published in Network Computing online edition, you can read the full version here.