Emerging trends in cloud computing security: a bibliometric analyses

IET SoftwareVolume 13, Issue 3 p. 223-231 ArticleOpen Access Emerging trends in cloud computing security: a bibliometric analyses Deepak Garg, Deepak Garg Chitkara University Institute of Engineering and Technology, Chitkara University, Punjab, 140401 IndiaSearch for more papers by this authorJagpreet Sidhu, Corresponding Author Jagpreet Sidhu jagpreet.sidhu@juit.ac.in Jaypee University of Information Technology, Himachal Pradesh, IndiaSearch for more papers by this authorShalli Rani, Shalli Rani Chitkara University Institute of Engineering and Technology, Chitkara University, Punjab, 140401 IndiaSearch for more papers by this author Deepak Garg, Deepak Garg Chitkara University Institute of Engineering and Technology, Chitkara University, Punjab, 140401 IndiaSearch for more papers by this authorJagpreet Sidhu, Corresponding Author Jagpreet Sidhu jagpreet.sidhu@juit.ac.in Jaypee University of Information Technology, Himachal Pradesh, IndiaSearch for more papers by this authorShalli Rani, Shalli Rani Chitkara University Institute of Engineering and Technology, Chitkara University, Punjab, 140401 IndiaSearch for more papers by this author First published: 01 June 2019 https://doi.org/10.1049/iet-sen.2018.5222Citations: 4AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Abstract Cloud Computing (CC) has gained popularity in industry and academia. CC is implemented by the industries on a large scale. Still, a lot of efforts in research for cloud computing are required. Improving security helps in abolishing the major problems of a domain. Therefore, research and development in security techniques are required. It is important to state the existing status of research. As publications are practically multiplying since 2008, a bibliometric analysis is a need of the hour. This study provides a comprehensive view of cloud security for a relevant time frame. Total 15,591 publications related to security of CC were investigated based on the Scopus database. This study analyses research publications on various parameters such as (i) publishing patterns (e.g. contributing authors, affiliations), (ii) analysis of common key terms, (iii) key term bunching to identify domain of interest, (iv) citation patterns, (v) publications medium, and (vi) researchers who aid in exploring research productivity in this specific domain. It analyses the literature based on the quantitative features and characteristics of cloud security based on meta-perspectives. The proposed analytical study will serve as an important tool for significant debate on future research schemas. 1 Introduction This is an era of ‘Cloud Computing’ (CC). It has gained popularity in industry and academia. With the ease of CC, the consumer no longer needs to invest heavily in Information Technology (IT) infrastructure. Cloud Consumers (CCr's) can use employee resources from cloud and pay-as-you-go model with elastic resource provisioning and broad network access. National Institute of Standards and Technology (NIST) has defined CC as ‘It is a model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources (e.g. networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction’ [1]. CC has reformed how software and IT infrastructure are engaged by consumers. CC adaptation has prompted the occurrence of computing as the fifth utility [2]. Since its emergence, industry organisations, governmental institutions, and academia have embraced it. But CC is not considered mature enough as an alternative to traditional computing models. It is still, a developing field of research on various dimensions. Business organisations and government agencies are seeking interest due to the cost-effectiveness of CC because they do not entail for huge expenditures on expensive software/hardware which can become superseded. Several current issues have not been completely addressed in the past research on CC, whereas new challenges keep on evolving from industrial applications [3]. Fig. 1 represents the research issues in CC. Research issues in CC are related to energy management, security, incorporation of cloud with an Internet of Things (IoT), trust management, traffic analyses, and management. However, most of them also have an individual security issue. Improving security helps to decrease or abolish some problems from domain [4]. In previous years, the researchers are working continuously to enhance security, so that cloud users, applications, and information are correctly managed and protected. Fig. 1Open in figure viewerPowerPoint Research issues in cloud computing According to 2018 report produced by cipher cloud [5], it revealed latest cloud security issues (i) 64% organisation had experienced phishing attack, (ii) 59% consider ransomware to be their biggest threat and (iii) 24% companies have experienced DDOS attack. It prompts a need for implementing more efficient and secured techniques to manage application-level security in CC. Reports produced by Cyber Security Insiders [6] reveals nine out of ten cyber-security professionals are concerned about cloud security where the top three cloud security challenges include data loss (67%), privacy (61%) and confidentiality (53%). A study conducted by IDG (International Data Group) [7] stated that the top barrier to cloud adoption is data protection as 64% are concerned for the privacy of their data. According to IDC (International Data Corporation), 2016 report [8], by the end of 2018 respondents expect to increase their cloud spending by ∼44%. So, there is a need for research and development in security techniques and technologies for CC. It is significant to state the present status of research in the security domain of CC. To achieve this objective, a research study is needed, as the number of publications is practically multiplying since 2008. But the impact is negligible as verified by industry reports [5-8]. To identify the gap between published research and solutions a bibliometric analysis is a need of the hour. Bibliometric analyses are a type of literature analyses based on quantitative features and characteristics of a specific research domain based on meta-perspectives [9-11]. By providing a view on meta-perspective [12, 13] on the literature, this paper discovers current knowledge and developments [9, 14, 15] in the specific research domain. Various investigational measures are applied to analyse the productivity of the specified research domain. Thus, it helps in investigating the collection of distributions based on frequency count and observes the type of citations. Further, it examines literature based on information sharing, quality, structure, affiliation and financial effect of the research [12, 14-19]. Additionally, bibliometrics analyses also investigate increasing or decreasing the impact of research institutions [18]. So, while analysing literature, it was observed limited work is presented in this direction. In [20] productivity of authors and contributing countries were analysed for 510 publications that were related to CC (2001–2010) based on Web of Science (WoS) database. The authors in [21] examined the distribution of articles, authors, subjects and funded articles (1993–2010) on a total of 89 journal articles related to CC based on Chinese Journal Full-text Database (CNKI) in China. The authors in [22] analysed key term clusters related to subject topics and wide-ranging perceptions in publication patterns, research impact, and productivity. In [23] the authors analyse the growth of cloud security (2008–2011) in China, 103 articles were investigated out of which 76 journal articles were obtained from CNKI. It also analysed contributing affiliations in cloud security. But it lacks in providing research trends, citation patterns and maximum cited publication related to cloud security. As most of the analyses are done on a small count of publications for specific domain [22] and they applied a straight count method. For generating the novel insights like evaluating the productivity of algorithms, authors or to analyse key terms bunches, bibliometrics techniques play a significant role. To present novel insights, the aim is to describe the current position of cloud security in a relevant time frame. In [22], a variety of methods are applied which includes quantitative and computational algorithms to analyse key aspects of security. The frequency of publications in CC is exponentially increasing annually from 2010 as illustrated in Fig. 2. According to Google Scholar, a search result doubles each year since 2008. Same growth is also predicted from scientific literature portal (Scopus). In 2009, Scopus listed 136 publications related to CC. As of 28 August 2018, Scopus lists 66,534 relevant publications while 15,591 publications of security in CC. To the best our knowledge, bibliometric analyses on the security of CC is a completely unexplored domain. Fig. 2Open in figure viewerPowerPoint Frequency of research publication In this article, total 66,534 publications related to security of CC are investigated based on Scopus database (2009–2018). This article analyses and empirically explores a count of peer-reviewed publications. After-effects of the present investigation remain wide experimental premise and may urge researchers to conduct complete bibliometric studies in some other scholastic orders. The objective of this paper is to throw light on (i) publishing patterns (e.g. contributing authors, affiliations), (ii) analysis of common key terms, (iii) key term bunching to identify a domain of interest. Other bits of knowledge like (i) citation patterns of journals, (ii) publications outlets, (iii) affiliations and (iv) the authors’ aids in exploring research productivity of affiliations and researchers. Consequently, this paper presents knowledge from the point of view on evolution, state, and trends [24-26]. The remaining paper is organised as follows. Section 2 briefly describes the methodology applied for bibliometric analyses. The current focus of CC research and dependencies between topics are observed based on key term clusters in Section 3. In Section 4, publication patterns are investigated and further analysed to understand general composition from various perspectives. Subsequently, the impact and productivity of CC research are examined in Section 5. Finally, a conclusion is presented in Sections 6 and Section 7 has been included in the heading of open challenges and future directions. 2 Methodology Due to a specific domain (security of CC) under consideration, the analysis is based on 15,591 number of publications which leads in the direction of limited inference during this phase. It includes extensive observation period and uses a variety of methods to analyse key aspects. 2.1 Pre-processing of research data Before analysing publishing patterns, initially, data was collected and pre-processed (cleansing). Initial data collection includes publications and citations details from scholarly portals [13]. This section illustrates the extensive plan of identifying peer-reviewed articles spread across the last decade. 2.2 Bibliographic analyses plan Manual handling of bibliographic information is labour and cost intensive [15], Elsevier's Scopus database is utilised to gather and process organised information of articles. In the case of bibliographic databases Scopus database is very much different from other, (i) Articles covered by Scopus are double then WoS for this specific domain, which incorporates article-in-press for publications as well, (ii) Scopus gives progressive functionality to export organised information which includes reference and bibliographic data in addition to abstracts, key terms, and references in contrast to other bibliographic databases. A general impediment of using bibliographic databases is, notwithstanding, that novel articles (like article-in-press) are often not covered which shows a decreased count of publications for the year 2017–2018. 2.2.1 Research trends To cover extensive publications in CC, a generic search query ‘(TITLE-ABS-KEY(cloud AND computing))’ was used for ‘title, abstract, and key terms’. The result generated a list of 66,534 articles during an observation period 2009–2018 (as of 28 August 2018). A process of data cleansing was carried to detect articles for complete and accurate data and metadata (does not specify authors, title, double entries etc. are removed). Finally, 15,591 publications and 32,620 key terms are retained that were specifically related to security in CC, 97.41% of publications are composed in the English language. Data were segmented and analysed from different perspectives. Firstly, the articles are investigated to estimate disciplines indulged in the progress of the field. Secondly, contributing countries are analysed based on publications count and maximum citations. Finally, the analyses include a count of authors involved in each article, the distribution of document categories and the number of publications per outlet. 2.2.2 Research contribution Researchers of all disciplines working hard to add new knowledge. Research articles are a primary source of knowledge for subjects under research study. Every research article has some research objectives which define the contribution made by that research article. Like article from a field of physics may propose a mathematical model to show the behaviour of light near black holes. Similarly, researchers from the field of civil engineering can propose a model for stress-testing bridges. There are countless specific research contributions. But types of contributions which generate new facts are quite a few. The examples in upcoming sections can be classified to a different type of contribution based on (i) academic contribution, (ii) contributing country, (iii) number of authors, (iv) average count of references, and (v) Research outlet (conference, book chapter, and journal). 2.2.3 Research productivity (validation/quality) Productivity is a quintessential indicator of efficiency in any production system. In bibliometric research, productivity can be defined on some parameters. The parameters may include (i) number of publications per researcher, and (ii) impact of publications. This section validates the influence of citations in research by analysing citing a pattern of various outlets and individual researcher's work. Finally, the comparative ranking is performed to validate the results of analysed patterns. 3 Research trend analyses To investigate key topics and aspects, it was required to classify and aggregate bibliographic information by analysing key terms and clusters. Key terms are used to categorise the content of literature which is related to the specific domain. Key terms establish key themes and characteristics of distinct research contribution. The rise of current research topics can be immediately recognised by the frequency and rate of key terms within a specific time interval. By examining the occurrence of key terms, it is likewise conceivable to recognise topics or perspectives that are strongly linked to each other. 3.1 Keyword analyses While analysing literature 32,620 distinctive key terms were identified. Note that key terms are not generally determined by the authors. If there were missing key terms, previously recorded key terms are allotted by experts [27]. This interpretation indicates that key terms are defined for 95.64% of studied publications, while for 10.33% of those publications; listed key terms have been allotted by Scopus. With respect to the normal distribution of key terms per publication, it was observed that usually three to six key terms are utilised to list objective of publication. But in case of security in CC, frequency and count of key terms are greater than the general perception specified. The end goal is to diminish inconsistency of key terms; publishers often provide a list of key terms relevant for a specific journal or conference. Few editors provide a list of key terms that are related to a particular conference or journal. Key terms with high occurrence are shown in Fig. 3. Results illustrate current research is focused on computing (33.06%), security (25.4%) in contrast to technology (5.3%), virtualisation (6.02%), services (6.91%) and other (3.01%). Current challenges in security that are yet to be overcome are privacy (3.29%), authentication (6.23%) and access control (7.86%). Literature uncovers that discussions in these fields are on-going [24, 26, 28-30]. This shows publications have a huge impact in directing research in security domain (25.4%). Well-known key terms in various other research fields are also uncovered, like the internet of things, grid computing and data mining. Fig. 3Open in figure viewerPowerPoint Frequency of key terms in the literature 3.2 Cluster formation The domain of interest is usually portrayed by more than one key term; additional analyses were performed on co-occurrences of key terms, also known as key term clusters. Frequent key term clusters uncover the links between facets and themes. Despite the fact analyses of highest occurrence of key terms straightforward, analyses of key term clusters are computationally overwhelming since each conceivable combination of significant key term needs to be compared. Method expands the length of the key term cluster to identify all important co-occurrences. Fig. 3 shows the key term cluster analyses with two or more elements. To get significant key term clusters, word CC was expelled since it mainly demonstrates a connection with CC research. The findings reveal a dense interrelation between specific key terms. For example, it reveals that terms virtual machine, virtualisation, or virtual reality all are almost used together. Similarly, other element key term clusters are a mix of terms and all lie under various common key terms of the domain (Fig. 3). By analysing key term clusters, it is conceivable to recognise dependencies among key terms. These findings help to comprehend better relevant topics and how they are associated with each other. Moreover, key term cluster analyses help in establishing a new research field and the relationship between topics. 4 Author names and affiliations This section analyses the general structure and development of security in CC in various academic disciplines, contributing regions, authors, citation pattern, and outlets. 4.1 Analysing based on academic disciplines and contributing country Based on publication outlets, each article was classified in more than one subject, categorisation of each article was done as per information conceived from Scopus [27] (Table 1). Table 1. Year wise (%) publications subject areas Subject area 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 Avg. Computer Science 59.62 59.45 60.34 60.22 57.02 56.50 55.61 51.60 50.16 47.07 55.76 Engineering 10.58 13.28 15.01 16.19 19.67 23.33 20.72 18.70 18.66 22.14 18.19 Mathematics 13.46 13.71 10.65 9.74 10.10 7.81 9.88 9.46 11.69 10.44 10.38 Decision Sciences 3.37 2.74 1.71 2.15 1.99 2.15 2.41 5.48 5.68 4.68 3.04 Social Sciences 4.81 4.33 4.43 4.24 4.03 3.07 3.45 3.81 2.85 1.96 3.78 Business and Accounting 1.92 2.16 3.11 2.15 2.57 2.31 2.21 1.64 1.62 1.13 2.22 Medicine 0.00 1.15 0.70 1.25 1.36 1.24 1.37 2.32 2.22 0.84 1.45 Physics and Astronomy 2.40 0.43 0.78 1.31 0.53 0.64 0.84 2.05 2.49 3.06 1.14 Materials Science 1.44 0.43 0.47 0.90 0.53 0.44 0.74 1.30 2.02 2.15 0.85 Biochemistry and Biology 0.00 0.00 0.39 0.42 0.63 0.92 0.80 1.05 0.69 2.28 0.61 As stated by ‘Gartner's Hype Cycle Theory’ (2010–2011) expectations from CC reached peak [31], which was reflected by the percentage of contributions on CC in various disciplines (Table 1). The following observations are analysed (i) contribution in computer science is continuous, (ii) development of secured algorithms for other disciplines are in an early phase, and (iii) a peak of popularity and lack of expectation can be identified in business related domains. It points toward the fact that current research is influenced by on-going expectations. Data demonstrates major contributions are related to computer science. Hence it illustrates study is concerned with the knowledge of a specific domain itself. Same observations are obtained for other publications, such as in [30] it is essential to consider business-related issues linked with security in CC. In addition to the applications’ trends of cloud computing, CC also provides advantages in mathematics and engineering fields. As indicated by reports and/or surveys conducted [5, 6, 32-35] expectations are trending in the direction of increasing use of CC and it will exponentially grow in the future with the progress in security algorithms. Also, the interaction between social and business-related disciplines will increase with a specific goal to understand the implications of CC from alternate perspectives. To obtain insights from contribution patterns, this segment examines publications according to country and authorship patterns. As shown in Fig. 4 most of the research was done by researchers from China (29.84%) followed by India (23.86%). The graph illustrates a general overview of the highest contributing countries and publications with at least ten citations. It is evident that China (29.84%) followed by India (23.86%) contribute significantly to this domain. In the case of citations, Canada (15.18%) followed by the USA and Australia and China ranked 8. Even though China contribute significantly to research contribution (no. of publications) but researchers should pay attention to the quality of the papers as researchers from Canada (15.18%) are more followed and citied. Fig. 4Open in figure viewerPowerPoint Contributing countries 4.2 Influence of number of authors per publication An average number of authors per publication (over a decade) is shown in Fig. 5. It illustrates the major publications have one, two and three co-authors. A contribution by a single author is significant (8.45%) in contrast to five authors contributions are significant (10.65%). It seems security in CC is more dominant towards collaboration in contrast to the individual. A distinct number of authors may have a validation advantage over research by the individual researcher. Fig. 5Open in figure viewerPowerPoint Co-authorship distribution (n = 12,437) 4.3 Average count of referencing Table 2 indicates the patterns of publications with at least 1 citation (n = 6466). A row in the table illustrates an average count of references (f) based on citations of publication. A total number of considered publications were stated by (n) (e.g. publication having at least 101 citations has 124.3 average references). It was observed publications cited by at least 51 contain 69.64 average references (f). The scope of the literature was recognised as primary criteria to identify a good quality of research [36]. These results are based on extensive research; mostly journals restrict the total number of pages that can be used for writing research articles which influence the total count of references. Table 2. Referencing patterns Min. citations n ƒ 1 6466 6.26 51 147 69.64 101 50 124.3 201 24 174.42 351 20 250.25 4.4 Publication outlet Selection of an outlet influence the visibility and impact of an article. This section analyses outlet (for research) prefers to convey their thoughts and bits of knowledge to the research community. As the data collected, contain metadata regarding the type of document, so it was possible to analyse. Table 3 illustrates on an average, 64.46% of the articles are published in the conference proceedings. This clarifies the fact; maximum research contribution is presented and published in conferences (64.46%) in contrast to books (0.59%), editorial (0.16%) as shown in Table 1. Conference publications seem to be the primary source of contribution [37, 38] because journals have high review and publication time. As CC is an evolving area of research, consequently timely demonstration of the notion is much preferred over justification; else, it might get obsolete or other researchers can present it in one or other way. Table 3. Count of publications by document type % Wise 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 Overall, % conference paper 73.53 75.00 72.68 72.92 65.30 57.53 58.45 54.60 59.24 45.04 64.46 article 16.18 14.35 15.87 16.98 23.85 29.26 31.53 34.79 28.53 36.32 24.39 conference review 6.618 7.83 7.13 4.93 5.52 4.95 3.81 3.81 4.17 2.74 5.27 book chapter 1.471 0.87 1.40 3.23 2.92 5.66 4.16 3.73 1.45 2.29 2.93 review 0 0.87 1.51 0.89 1.43 1.58 1.25 1.89 1.79 1.25 1.40 editorial 0.735 0.00 0.32 0.08 0.00 0.16 0.05 0.28 0.38 0.35 0.16 book 0.735 0.43 0.43 0.81 0.84 0.71 0.55 0.59 0.34 0.15 0.59 5 Research validation Research validation means to which extent results can be considered a true reflection of underlying ability. This section discusses how the number of citations influences research. 5.1 Influence of citations in research With a specific goal to quantify research impact, a count of individual citations was analysed. It calculates (i) citation count of conferences, journals, and authors, (ii) impact of citations by individual publication, (iii) to consider the publications longevity normalised citation impact index (NCII) is considered so that accurate and reliable results can be obtained. Concerning research productivity and research impact, ‘Matthew effect’ [39] which depicts that highly recognised researchers got credit for contributions that are exhibited by numerous other researchers. As credit given by the researcher's companions again impacts acknowledgment, an impact is also advantageous for the authors also. The visibility of the author and/or publication is influenced by system enrolment impressions, e.g. influential journals, look into research institutes or research joint efforts [40]. While counts of former subsections give a bit of knowledge into publishing patterns and key disciplines, a crucial concern of this analyses is to assess the effect of contributions. Total count of citations of a publication is one of the measures for examining the effect of contributions. Citation count of a publication expresses usefulness of publications and number of times a publication is referred into other publications. 102,973 citations were received for the overall count of publications into consideration. The citation per publication ranges between 0 and 983. The following section evaluates the impact of contributions from alternative perspectives. 5.1.1 Citing pattern and citations per outlets In the previous sections effect of distribution and citations was analysed. As studied in the literature, time effects count of citations the article receives (1) was utilised to make the citation count for several years comparable. NCII considers ‘lifespan of publications which refers to the number of year's publication has been in print’ [15] (1)Data exhibited in Table 4 shows some interesting patterns. One can clearly observe that the Avg. NCII score/publication (pub.) is falling which shows the critical effect on scheduled and key publications. As Scopus has not yet covered publication of the year 2018 (Fig. 2) is the only reason behind declining of Avg. NCII score/publication (pub.). Table 4. General citation patterns Year 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 number of pub. 136 460 926 1237 1539 1840 1995 2546 2903 2009 number of citations 7180 13,772 15,693 14,957 15,435 11,969 10,394 8637 3932 1004 Longevity, years 10 9 8 7 6 5 4 3 2 1 overall NCII score 718 1530.22 1961.63 2136.71 2572.50 2393.80 2598.50 2879 1966 1004 avg. NCII score/pub. 5.28 3.33 2.12 1.73 1.67 1.30 1.30 1.13 0.68 0.50 Further analyses of citations based on various publication outlets were performed. Table 5 illustrates the primary sources of references are from conference articles (19.06%) and journal articles (12%). Contributions per outlet are analysed in Section 4.4; it was observed that journal contributions receive more citations than other outlets of research contribution. In contrast, books and/or book chapters have limited contribution. This observation conflicts with other domain of research [18], where books and book chapters are frequently cited [12, 16]. Although survey article contributions are limited as per Section 4.4, they received a high rate of citations due to the increasing interest of researchers in this domain. Table 5. Percentage of citations per outlet (n = 7582) Outlet 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 Avg. conference paper 1.39 2.51 4.29 6.03 6.51 8.84 11.22 16.08 43.72 90.04 19.06 journal articles 0.31 0.48 0.94 1.40 2.38 4.49 6.05 10.25 21.06 72.61 12.00 review 0.00 0.03 0.09 0.07 0.14 0.24 0.24 0.56 1.32 2.49 0.52 conference review 0.13 0.26 0.42 0.41 0.55 0.76 0.73 1.12 3.08 5.48 1.29 article in press 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.06 2.90 23.71 2.67 book chapter 0.03 0.03 0