Lia Barbu’s 750-Word Expended Definition of Virtualization

TO: Prof. Jason Ellis

FROM: Lia Barbu

DATE: October 21, 2020

SUBJECT: Expanded Definition of  Virtualization


This document is an expanded definition essay of the technical term virtualization. In this document, I will try to define virtualization in the context of computer science. I will discuss several definitions of virtualization in the existing literature, followed by several contextual discussions. Finally, I will provide a working definition of the term.


Oxford English Dictionary defines the verb virtualize as “to give virtual existence to (an intangible or abstract idea, concept, etc.) by perceiving it as, or demonstrating it to be, manifested or present in a real object, action, etc., within the world” (Oxford English Dictionary, n.d.). Virtualization is a derivative of virtualize. Bhanu Prakash Reddy Tholeti, in his article “Hypervisors, Virtualization, and Networking,” says, “Virtualization is the creation of flexible substitutes for actual resources that have the same functions and external interfaces as their actual counterparts, but that differ in attributes such as size, performance, and cost. These substitutes are called virtual resources; their users are typically unaware of the substitution” (Tholeti, 2014, p.387). It means that virtualization uses the existing resources and creates virtual hardware or software with the same quality as a physical resource and less cost. The magic of virtualization is that the users are not aware that whatever they use is only virtual, not physical. Virtualization is the process of extending a computer’s resources multiplying the hardware and software. In this definition, the author highlights the users’ satisfaction. The difference between physical and virtual resources is untraceable. Cerling, Buller, Enstall, and Ruiz offer a more complex and detailed definition in their book “Mastering Microsoft Virtualization.” They say, “In the last few years, the word virtualization has been a topic of discussion in most, if not all, IT organizations. Not only has it promised to save organizations money, but it has consistently delivered on that promise. The first area that this has generally been applied to is the server space. Organizations often take three, four, or more physical servers, create virtual machines running what previously ran on a physical server, and run those workloads on a single physical server hosting multiple virtual machines. Reducing the number of physical servers saves the cost of purchasing, maintaining, powering, and in some cases licensing those physical servers” (Cerling, Buller, Enstall and Ruiz, 2010, p. XVII). The authors emphasize how, through what it does, virtualization is a hot subject for IT companies. Virtualization creates on one server virtual machines with capacities of more than one server. Using virtualization, an organization uses its resources at more than maximum capabilities. Using virtualization, the company reduces the cost of resources and all the other pieces that come with them, like maintenance. It is explained that virtualization in the last few years has become necessary for IT businesses. Compared with the previous definition, this approach highlights the advantages virtualization brings to IT organizations. Pearce, Zeadally, and Hunt, in their article “Virtualization: Issues, Security Threats, and Solutions,” tell us, “In essence, system virtualization is the use of an encapsulating software layer that surrounds or underlies an operating system and provides the same inputs, outputs, and behavior that would be expected from physical hardware” (Pearce, Zeadally, & Hunt, 2013, p. 17). This definition is describing how virtualization uses software to create hardware precisely as a physical one. It refers strictly to how the virtualization process works. It generates a virtual version of a resource giving the possibility to run different systems at once on it. 


Douglis and Kreiger tell us in their article “Virtualization” that, “Virtualization has been a part of the computing landscape for nearly half a century” (Douglis & Krieger, 2013, p. 6). This simple sentence gives us a lot of information about virtualization. It can be said that it synthetizes the age of virtualization in the computer science field. Jordan Shamir in his article “5 Benefits of Virtualization” says, “Despite being created decades ago, virtualization continues to be a catalyst for companies’ IT strategies” (Shamir, 2020, para 15). This shows how important virtualization in today’s IT environment. It is essential for a successful IT business.

Working Definition

Virtualization is the process of using the software in generating new resources with the same qualities and capabilities as physical ones, which is a plus for users and less costly, which is a plus for IT companies.  Even, in use for the last half of the century in this fast computing environment is still the primary mechanism in IT organizations’ plans.


Cerling, T., Buller, J., Enstall, C., & Ruiz, R. (2010). Mastering microsoft virtualization. Wiley Publishing, Inc

Douglis, F., & Krieger, O. (2013). Virtualization. IEEE Internet Computing, 17(2), 6–9.

Oxford University Press. (n. d.). Virtualization. In Oxford English Dictionary Online. Retrieved October 6, 2020, from

Pearce, M., Zeadally, S., & Hunt, R. (2013). Virtualization: issues, security threats, and solutions. ACM Computing Surveys, 45(2), 17–17:39.

Shamir, J (2020, April 8). 5 Benefits of Virtualization. IBM. Tholeti, B. R. (2014). Hypervisors, virtualization, and networking. In C. DeCusatis (Ed.), Handbook of Fiber Optic Data Communication: A Practical Guide to Optical Networking (4th ed., pp. 387-416). Academic Press.

Summary of Alden et al.’s “Cyber Security in the Quantum Era”

TO: Professor Ellis 

FROM: Lia Barbu

DATE: September 23, 2020

SUBJECT: 500-Word Summary

This memo is a 500-word summary of the article, “Cyber Security in the Quantum Era,” by Petros Alden and Elham Kashefi, both professors in the School of Informatics at the University of Edinburg. 

Cybersecurity is essential to protect our systems, and it should be ready for a new computational model as quantum technologies. Quantum theory was by far one of the significant technological developments of the 20th century. A breakthrough will be possible soon due to the research in the field. Quantum computers will be the most valuable quantum technology due to their computational power. Quantum technologies’ achievements already exist Google’s processor “Bristlecone” and satellite quantum communication.

Quantum computers are no longer a myth, and cybersecurity must prepare for this new era. Alden and Kashefi inform us, “Quantum technologies may have a negative effect to cybersecurity, when viewed as a resource for adversaries, but can also have a positive effect, when honest parties use these technologies to their advantage.” (Alden & Kashefi, 2019, p. 121). There are three scenarios: one everything is secure, and the other two explore what new challenges quantum technologies can create. In the first scenario, the honest party has classic technologies, and the adversary has a large quantum computer. In the second scenario, the honest party has limited access to quantum technologies, and the adversary can use any quantum technologies. The third scenario looks in the future: quantum computation devices and the parts implicated in the process would protect their data and be secure. The focus will be on quantum technology’s effects on cryptographic attacks and attacks on the new quantum hardware. 

Even though quantum attacks seem far away; there are three essential rationales why we must address it now: security can hit retroactively, to create secure cryptographic solutions, and to be ready to implement the new technology. Cybersecurity research in post-quantum cryptography is divided into three classes considering adversary use of quantum technology: classic technology with access to an oracle/quantum computer, modification of security definition, and changes required to the new protocol. There are cryptosystems considered secure to a quantum computer attack, and the article considers three issues: confidence, usability, and efficiency. Next is explained what can happen when the adversary can make changes to security notions and what steps should be taken to prevent and stop this action. Quantum rewinding is a technique that adds a mechanism that enforces malicious adversaries to behave as a weak one.

As quantum technologies develop, quantumly protocols should become a reality. Practicality includes research that includes quantum technologies presently achievable. Quantum gadgets open a door for new attacks like side-channels attacks. The security for this is the device-independence that comes with high resources cost. Standardization and protocols should be created for quantum technology. Quantum technology will become a significant part of the computing and communication environment. 


WALLDEN, P., & KASHEFI, E. (2019). Cyber security in the quantum era. Communications of the ACM, 62(4), 120–129.