Monshizadeh and Khatri
328
2) Integrity: points out data correctness as to whether the data has been modified or
corrupted. Malicious codes can be distributed by both insider and co‐tenant or via
external attackers on data storages [13]. Data encryption, data isolation, secure
protocols and intrusion detection can support data integrity and prevent data modification and corruption.
Another aspect of data integrity is data leakage prevention that can be achieved by
data sanitization [11,14–15] (encryption and data cleanup). Since multiple tenants
may share the same infrastructure or VM; e.g. virtual Home Subscriber Server
(vHSS), the cloud service provider is responsible for a complete data cleanup before
handing over VM to the next tenant;
3) Availability: covers the basic concepts of security, such as data recovery and resource
availability. Availability can be achieved via load balancing, redundancy and data
backup to prevent data loss. Threats such as DoS should be prevented by an intrusion detection mechanism.
In addition to the security requirements already discussed, legal aspects such as security warranties and compensation agreements among operators belonging to TaaS look
necessary. On the other hand, location of the cloud provider [16] (where the parent
company is registered) is important, since different countries have diverse laws; regardless of data centers location, in special circumstances, authorities will have access to
customer data.
14.4.2 Hypervisor and VM Security in TaaS
The concept of virtualized threats refers to every kind of attack against availability,
integrity and confidentiality of the hardware and software in a virtualized mobile
network. There are three elements in a virtualized network: hypervisor, VMs (virtual
hardware and images), and applications; all these elements should be adequately secured
against unauthorized access, change and destruction.
In a virtualized mobile network, the hypervisor itself is not directly connected to any
end user, and most threats arise through malicious VMs, therefore having a reliable
hypervisor requires secure VMs. While traditional security techniques such as IDS,
antivirus and FWs are still applicable for virtualized networks, isolation could be an
important approach towards security of VMs. Isolation will ensure that if one VM is
attacked, other VMs are not infected [17,18].
There are different methods such as security zones and traffic separation for VM
isolation. VMs with similar functionality and security requirements could be
grouped in same hardware. Each zone could be controlled by a different access list
defined in FW or dedicated IDS and so on. DeMilitarized Zone (DMZ) is an example of a security zone. Traffic separation is another method for VM isolation; similar
to traditional networks, traffic with different characteristics, functionality (e.g. CP
and charging) and security requirements would be assigned to different Virtual
Local Area Networks (VLANs) or VPNs, in this case sensitive traffic would be separated [19].
After discussing virtualized network security concerns, we now go through security
requirements such as authentication, availability and integrity:
328
2) Integrity: points out data correctness as to whether the data has been modified or
corrupted. Malicious codes can be distributed by both insider and co‐tenant or via
external attackers on data storages [13]. Data encryption, data isolation, secure
protocols and intrusion detection can support data integrity and prevent data modification and corruption.
Another aspect of data integrity is data leakage prevention that can be achieved by
data sanitization [11,14–15] (encryption and data cleanup). Since multiple tenants
may share the same infrastructure or VM; e.g. virtual Home Subscriber Server
(vHSS), the cloud service provider is responsible for a complete data cleanup before
handing over VM to the next tenant;
3) Availability: covers the basic concepts of security, such as data recovery and resource
availability. Availability can be achieved via load balancing, redundancy and data
backup to prevent data loss. Threats such as DoS should be prevented by an intrusion detection mechanism.
In addition to the security requirements already discussed, legal aspects such as security warranties and compensation agreements among operators belonging to TaaS look
necessary. On the other hand, location of the cloud provider [16] (where the parent
company is registered) is important, since different countries have diverse laws; regardless of data centers location, in special circumstances, authorities will have access to
customer data.
14.4.2 Hypervisor and VM Security in TaaS
The concept of virtualized threats refers to every kind of attack against availability,
integrity and confidentiality of the hardware and software in a virtualized mobile
network. There are three elements in a virtualized network: hypervisor, VMs (virtual
hardware and images), and applications; all these elements should be adequately secured
against unauthorized access, change and destruction.
In a virtualized mobile network, the hypervisor itself is not directly connected to any
end user, and most threats arise through malicious VMs, therefore having a reliable
hypervisor requires secure VMs. While traditional security techniques such as IDS,
antivirus and FWs are still applicable for virtualized networks, isolation could be an
important approach towards security of VMs. Isolation will ensure that if one VM is
attacked, other VMs are not infected [17,18].
There are different methods such as security zones and traffic separation for VM
isolation. VMs with similar functionality and security requirements could be
grouped in same hardware. Each zone could be controlled by a different access list
defined in FW or dedicated IDS and so on. DeMilitarized Zone (DMZ) is an example of a security zone. Traffic separation is another method for VM isolation; similar
to traditional networks, traffic with different characteristics, functionality (e.g. CP
and charging) and security requirements would be assigned to different Virtual
Local Area Networks (VLANs) or VPNs, in this case sensitive traffic would be separated [19].
After discussing virtualized network security concerns, we now go through security
requirements such as authentication, availability and integrity: