Hidden Channel Attack: Risks and Security Concerns Analysis

This essay delves into the critical domain of hidden channel attacks, specifically focusing on the risks and security concerns they pose within hypervisor systems. The essay begins with an introduction to virtualization and the role of the hypervisor, establishing the context for understanding these attacks. It then provides a background on virtualization, emphasizing its significance in modern cloud computing and the associated security considerations. The core of the essay analyzes the risks and security concerns of various hidden channel attacks, including inter-process and inter-virtual machine attacks, and details CPU load, cache-based, and time-based attacks. Furthermore, the essay explores mitigation techniques, categorized into application, system, and hardware-based approaches. The essay concludes by summarizing the key findings and discusses future trends in this evolving area of cybersecurity, emphasizing the ongoing need for robust security measures to protect virtualized environments.

Running head: HIDDEN CHANNEL ATTACK
Risks and security concerns with hidden channel attack
Name of the Student
Name of the University
Author’s Note

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Table of Contents
Introduction......................................................................................................................................3
Background......................................................................................................................................3
Risks and security concerns of Hidden channel attacks..................................................................4
Solutions of challenges....................................................................................................................7
Conclusion.......................................................................................................................................9
Future trends....................................................................................................................................9
References......................................................................................................................................10

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Introduction
The rapid development of the information technology has been helping in transforming
traditional computing into virtual machine system. This concept of the virtualization depends on
the virtual machine or hypervisor. Therefore, there have been various technical consequences
involved in the use of the hypervisor (Ibrahim, Hamlyn-Harris & Grundy, 2016). There is a
constant time implementation that can be used for providing instruction with a specific time
routine. This might help in mitigating risks in hidden channel attack. Correlations can be avoided
by removing branches and loops depending on private input data. These consequence have been
related to the security problems in the virtual machines.
This report outlines risks include in the hypervisor and various attacks in including
hidden channel attacks. The use of the system approaches might help in maintaining a different
approach in retaining the challenges in the hidden channel attacks in the hypervisor. Various
risks involved in the hypervisor have been discusses. This report provide basic solutions for risks
in the hypervisor.
Background
Virtualization is a concept that helps in increasing the efficiency of the computing
resources with in a time period. It helps in creating a virtual environment inside anther
environment and using systems resources including RAM and Processor (Zhang et al. 2018).
This helps in maintaining a keen approach to the maintenance of the computing resources.
Virtual machines are directly linked with the cloud computing resources. All the data and
information are stored over cloud. The use of cloud computing have been helping in providing
owned services. Security concerns in the virtualized systems requires several consideration

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related to the threats. It has been important to realize that the trust assumptions. Threats models
and security goals have been treated as proper assumption in the hypervisor. However,
virtualization has been the key foundation of the cloud computing and utility computing.
Risks and security concerns of Hidden channel attacks
The utilization of cryptography in various fields have been raising in recent years.
Applications of cryptography has been found in cloud computing for securing data and
information over the internet. Various cryptographic algorithms have been used in order to
maintain the security of the systems (Zhang et al., 2018). All attacks are focused on the secret
key of the cryptography system. Among all the attacks in the cryptography, hidden channel
attacks have been the most dangerous attacks. Various applications have various execution time
and allowing attackers to read these time. This type of attack require access to the virtual
machine encryption operations. However, cloud computing have been dependent on the
virtualization for accessing other guest operating systems (Bauman, Ayoade & Lin, 2015).
Therefore, cryptographic algorithms have been attacked easily by the attackers. Channel attacks
have been focused on the processor’s cache it huts hardware and software components. Different
information in hidden channel attacks have been maintaining a keen approach to the
development of threats in the hypervisor. There are various components of the hidden channel
attacks:
Inter-Process: This type of channel has been established between two processes
including spy process and victim process for running in same operating system. The use of inter
process channeling helps in maintaining a positive behavior of virtual machine. The spy process
needs to be move in parallel within victim process and properly synchronized.

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Inter-Virtual Machine: This channel can be either related to two virtual machines running
in same CPU core (Kumara & Jaidhar, 2015). Therefore, synchronization between two virtual
machines executing on other cores is more difficult. This kind of channel needs to be cope with
more noise than other inter-process channels. A hidden channel attacks has been created within a
network for yielding a noisier channel for network properties including latency.
Therefore, any end of attack might be passive or active in nature. In passive attacks,
attacker observes activities of goal without performing any kind of changes in target (Park et al.,
2016). The active attacks helps in changing the environment by changing the target to force in
performing abnormal activities. There are three types of hidden channel attacks incusing CPU
based, cache based and time based.
CPU Load based hidden channel: The CPU has been one of resources that can be shared
among multiple virtual achiness. Reducing at operating system and hypervisor levels have been a
proper choice fir lending proper existing cloud infrastructures with little changes (Iqbal et al.,
2016). Time padding helps in ensuring the execution time of the protected function. This
countermeasure has been developed in maintaining a keen approach in the development of the
strategies to mitigate hidden channel attacks in the hypervisor. The CPU load has been useful for
converting channel between two virtual achiness running on one CPU. There are different
operations in the CPU that can be involved in information leakage.
CPU Cache based hidden channel: Cache lines that can be used during encryption of
plain text passages that can help in revealing information for reconstructing an encryption key.
As L1 and L2 caches that are shared among processes moving on single core (Irazoqui & Guo,
2017). LLC has been shared among all processor in the CPU. The software implementation of
AES and look-up tables can be pre-calculated and stored in RAM for improving performance.

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However, encryption in CPU loads on tables into cache and tables can be used by encryption
process.
Time based Hidden channel: The time of execution of applications are cryptographic
ones for constant as it depends on execution time of algorithm instruction. Therefore, different
running of an algorithm results in different execution times. Therefore, cryptographic algorithms
have been attacked easily by attackers (Gorobets et al., 2015). Modular exponentiation has an
important operation used in implementation of different cryptographic algorithms including
AES. The use of hypervisor have been maintain the mitigating strategies from the challenges and
threats of hidden channel attacks. Time of execution of frequently used square and multiply
method. These type of attacks can be applicable to limited in the computing devices including
smart cards. Timing attacks might be local and remote.
This type of attack require access to the virtual machine encryption operations.
Therefore, as a local attack, a spy program can be ran on same machine as victim program. In a
remote attack, victim and attacker can be hosted on different machines (Wang et al., 2017). This
type of attacks can be applicable to the cloud based cryptosystems. All attacks are focused on the
secret key of the cryptography system. Among all the attacks in the cryptography, hidden
channel attacks have been the most dangerous attacks. Various applications have various
execution time and allowing attackers to read these time. However, cloud computing have been
dependent on the virtualization for accessing other guest operating systems.
Cache based timing attacks uses cache memory for locally attacking a cryptographic
system. This attack has been occurred in in the DES by inferring S-box inputs for measuring
encryption time of different plaintexts (Nezarat & Shams, 2017). The encryption algorithm might
change due to memory activity including cache access. The attacker might tries for finding

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different relation between accessed cache lines and an encryption process. The attackers exploits
pattern of cache accesses for the victim. Therefore, different profiles of the victim have been
attacked for breaching out data and information from it. Virtual machines have been using data
and information stored in the local computers and CPU. Therefore, attacks in the virtual
machines might create problems for the local users.
These types of attacks are easy to execute as the time gap between two processes have
been measured by the attackers before attacking into the machine (Ogasawara & Kono, 2017).
The use of the time stand protocol, the time used for processing of the data and information
needs to be calculated. Thus helps in entering into the network layer of the virtual machine and
breach data and information from the cache memory. A hidden channel attack need two virtual
machines that have been residing on the same physical host. However, in across virtual machine
attack, an alternative place of malicious behavior of virtual machine on the physical host of the
victim.
Solutions of challenges
Mitigation techniques for hide channel attacks have been divided into three classes
according to the enforcement layer in infrastructures including application system and hardware.
There have been various approaches to the development of several models for security of the
virtual machines from performance model.
Application based approaches: Design oriented solutions helps in enhancing SCA
resistance of ciphers. Robust and constant-time algorithms helps in eliminating SCAs under
timing (Sgandurra & Lupu, 2016). There is a constant time implementation that can be used for
providing instruction with a specific time routine. This might help in mitigating risks in hidden

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channel attack. Correlations can be avoided by removing branches and loops depending on secret
input data. Masking cryptographic algorithm inputs can be possible by randomization techniques
(Annapoorani, Srinivasan & Mylavathi, 2018). Time padding is a technique for timing SCA
mitigation with the introduction of delay in function for hiding their time leaks. Key-dependent
control flow and dataflow need to be main cause of timing variations and correlation among
secret data and time of execution.
System based Approaches: Reducing at operating system and hypervisor levels have been
a proper choice fir lending proper existing cloud infrastructures with little changes. The use of
the system approaches might help in maintaining a different approach in retaining the challenges
in the hidden channel attacks in the hypervisor (Jin et al., 2015). All attacks are focused on the
secret key of the cryptography system. Among all the attacks in the cryptography, hidden
channel attacks have been the most dangerous attacks. This type of attack require access to the
virtual machine encryption operations. The use of hypervisor have been maintain the mitigating
strategies from the challenges and threats of hidden channel attacks. Time padding helps in
ensuring the execution time of the protected function. This countermeasure has been developed
in maintaining a keen approach in the development of the strategies to mitigate hidden channel
attacks in the hypervisor.
Various cryptographic algorithms have been used in order to maintain the security of the
systems (Irazoqui & Guo, 2017). This approach has been scheduled with different threads that
can be helping in the executing performance counters. All attacks are focused on the secret key
of the cryptography system. Among all the attacks in the cryptography, hidden channel attacks
have been the most dangerous attacks. Various applications have various execution time and
allowing attackers to read these time. Cache line locking system has been an OS mechanism for

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preventing cache based SCAs in the cloud. Using processor with exclusive cache of possible for
inclusive caches that are widely exploited by hackers for performing SCAs. However, Intel SGX
does not protect against side-channel attacks as content of memory lines protected by Intel SGX.
Conclusion
It can be concluded that use of virtual machine have been helping in enhancing the
efficiency of computing resources. Virtual machine or hypervisor has been creating opportunities
for parallel tasking of the computing resources. All attacks are focused on the secret key of the
cryptography system. Among all the attacks in the cryptography, hidden channel attacks have
been the most dangerous attacks However, there have been some security threats involved in the
hypervisor including hidden channel attacks. Risks involved in the hidden channel attacks have
been discussed in the report. Risks have been identified in the report for the preparing strategies
to mitigate them. Various applications have various execution time and allowing attackers to
read these time. This type of attack require access to the virtual machine encryption operations.
Proper analysis of the risks have been done in the report. Mitigation strategies for hidden channel
attacks have been provided in the report.
Future trends
The researcher might look for an alternatives for mitigating strategies of hidden channel
attacks. There might be further deep studies on the hidden channel attacks in the hypervisor and
mitigating strategies might be prepared. Risks analysis management might be done for analyzing
the severity of the risks involved in the hypervisor or virtual machine.

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References
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