Salo and Liyanage
406
With respect to the Cloud Service Providers (CSP), the following security issues were
identified by the Focus Group [22]:
● Ambiguity in responsibility: different user roles, such as the Cloud Service Provider,
cloud service user, client IT admin and data owner, may be defined and used in a
cloud system. Ambiguity of such user roles and the responsibilities definition related
to the data ownership, access control, infrastructure maintenance, etc, may induce
business or legal dissention;
● Protection inconsistency: due to the decentralized architecture of a cloud infrastructure, its protection mechanisms are likely to be inconsistent among distributed
security modules;
● Bylaw conflict: depending on the bylaws of the hosting country, data may be protected
by different applicable jurisdictions. For instance, the USA Patriot Act may authorize
such seizures. The EU protects cloud service user’s private data, which should not be
processed in countries that do not provide a sufficient level of guaranteed protection.
An international Cloud Service Provider may conflict with the bylaws of its local data
centres, which is a legal threat to be taken into account;
● Business discontinuity: the “as a service” feature of cloud computing allocates
resources and delivers them as a service. The whole cloud infrastructure, together
with its business workflows, thus relies on a large set of services, ranging from hardware to application. However, the discontinuity of service delivery, such as a black‐out
or delay, may have a severe impact on the availability;
● Shared environment: cloud resources are virtualized and different cloud service users
(possibly competitors) share the same infrastructure. Any unauthorized and violent
access to cloud service user’s sensitive data may compromise both the integrity and
confidentiality;
● Hypervisor isolation failure: the hypervisor technology is considered as the basis of
cloud infrastructure. Multiple virtual machines co‐hosted on one physical server
share both CPU and memory resources, which are virtualized by the hypervisor. This
threat covers the failure of mechanisms to isolate attacks that could be launched on a
hypervisor to gain illegal access to the memory of other virtual machines,
● Service unavailability: availability is not specific to the cloud environment. However,
because of the service‐oriented design principle, service delivery may be impacted
while the cloud infrastructure in not available. Moreover, the dynamic dependency of
cloud computing offers many more possibilities to an attacker. A typical denial of
service attack on one service may blog the whole cloud system;
● Abuse by Cloud Service Provider: for a cloud service user, migrating a part of its own
IT to a cloud infrastructure, implies to partially give control to the Provider. This may
lead to a misconfiguration or malicious insider attack.
The Security and Privacy issues reported on NIST guidelines on Security and Privacy
in Public Cloud Computing [23] are very much the same or similar to those listed above.
The following first two issue descriptions can be seen to further explain the issues
above. The third issue (Visibility) is complementary to the issues above:
● Loss of control: (see Loss of governance above). Transitioning to Cloud’s architecture
requires a transfer of responsibility and control to the cloud provider, over information as well as system components that were previously under the organization’s
406
With respect to the Cloud Service Providers (CSP), the following security issues were
identified by the Focus Group [22]:
● Ambiguity in responsibility: different user roles, such as the Cloud Service Provider,
cloud service user, client IT admin and data owner, may be defined and used in a
cloud system. Ambiguity of such user roles and the responsibilities definition related
to the data ownership, access control, infrastructure maintenance, etc, may induce
business or legal dissention;
● Protection inconsistency: due to the decentralized architecture of a cloud infrastructure, its protection mechanisms are likely to be inconsistent among distributed
security modules;
● Bylaw conflict: depending on the bylaws of the hosting country, data may be protected
by different applicable jurisdictions. For instance, the USA Patriot Act may authorize
such seizures. The EU protects cloud service user’s private data, which should not be
processed in countries that do not provide a sufficient level of guaranteed protection.
An international Cloud Service Provider may conflict with the bylaws of its local data
centres, which is a legal threat to be taken into account;
● Business discontinuity: the “as a service” feature of cloud computing allocates
resources and delivers them as a service. The whole cloud infrastructure, together
with its business workflows, thus relies on a large set of services, ranging from hardware to application. However, the discontinuity of service delivery, such as a black‐out
or delay, may have a severe impact on the availability;
● Shared environment: cloud resources are virtualized and different cloud service users
(possibly competitors) share the same infrastructure. Any unauthorized and violent
access to cloud service user’s sensitive data may compromise both the integrity and
confidentiality;
● Hypervisor isolation failure: the hypervisor technology is considered as the basis of
cloud infrastructure. Multiple virtual machines co‐hosted on one physical server
share both CPU and memory resources, which are virtualized by the hypervisor. This
threat covers the failure of mechanisms to isolate attacks that could be launched on a
hypervisor to gain illegal access to the memory of other virtual machines,
● Service unavailability: availability is not specific to the cloud environment. However,
because of the service‐oriented design principle, service delivery may be impacted
while the cloud infrastructure in not available. Moreover, the dynamic dependency of
cloud computing offers many more possibilities to an attacker. A typical denial of
service attack on one service may blog the whole cloud system;
● Abuse by Cloud Service Provider: for a cloud service user, migrating a part of its own
IT to a cloud infrastructure, implies to partially give control to the Provider. This may
lead to a misconfiguration or malicious insider attack.
The Security and Privacy issues reported on NIST guidelines on Security and Privacy
in Public Cloud Computing [23] are very much the same or similar to those listed above.
The following first two issue descriptions can be seen to further explain the issues
above. The third issue (Visibility) is complementary to the issues above:
● Loss of control: (see Loss of governance above). Transitioning to Cloud’s architecture
requires a transfer of responsibility and control to the cloud provider, over information as well as system components that were previously under the organization’s