# From Transactions to Transformations: A Bibliometric Study on Technology Convergence in E-Payments
## 4 Result Analysis
### Network Analysis
#### 4.2.2 Thematic Analysis  
The thematic map shown in Figure 7 and Table 6 is divided into four quadrants, each representing a different status of research themes within the context of e-payment technology evolution. Upper Left Quadrant--\"Niche Themes\":  
These are topics that have a high development degree but low centrality. They are well-developed and mature in their research lifecycle but are currently specialized and not central to the field of e-payment. Examples might include advanced or highly specialized topics like \"cryptanalysis\" or \"classical messages\" that are important within their own subfields but do not currently influence the core of e-payment research. Upper Right Quadrant--\"Motor Themes\":  
These themes are well-developed and have high centrality, meaning they are mature and influential within the field. They drive the research agenda and are fundamental to the current understanding and advancement of e-payment technologies. Here, we find topics like \"cryptography,\" \"trust,\" \" e-business,\" and \"electronic commerce,\" which are key areas of focus that push the field forward. Lower Right Quadrant--\"Basic Themes\":  
These themes have low developmental degree but high centrality. They are central to the field and form the foundational concepts of e-payment research, even though they may not be at the forefront of current research development. Fundamental concepts such as \"security,\" \"authentication,\" and \"digital signature\" protocols are located here. These are the building blocks upon which more complex systems and ideas are developed. Lower Left Quadrant--\"Emerging or Declining Themes\":  
These topics have low centrality and are at the early or declining stages of their development degree. They might be areas that are just beginning to be explored within e-payment research or once were of interest but are now losing relevance due to technological advancement or shifts in research focus. Topics such as \"algorithm optimization\" might be emerging, reflecting new methods to enhance e-payment processing, while \"signature schemes\" might decline as newer verification and validation forms are developed. In terms of the evolution of e-payment technology, this map provides a snapshot of how different concepts have evolved and their current standing in the research landscape. \"Motor Themes\" like \"cryptography\" have evolved to become essential, driving the security aspect of e-payment systems. \"Basic Themes\" like \"security\" represent the fundamental concerns that have always been central to the field. \"Niche Themes\" could represent areas like \"cryptanalysis\" which are critical to understanding and developing secure e-payment \begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline
**Quadrant** & **Theme Description** & **Keywords/Topics** \\ \hline
**Motor Themes** & Core research driving e-payment field such as trust, cryptography, and e-commerce [28; 29; 30; 31] & cryptography, trust, e-business, electronic commerce \\ \hline
**Basic Themes** & Foundational topics in digital security such as authentication and digital signature [16; 17; 32] & security, authentication, digital signature \\ \hline
**Niche Themes** & Specialized and advanced areas like cryptanalysis, studied in depth but less central [18; 33] & cryptanalysis, classical messages \\ \hline
**Emerging or Declining Themes** & New or fading topics including optimization and legacy verification methods [20; 34] & algorithm optimization, signature schemes \\ \hline \end{tabular}
\end{table} 
Table 6: Thematic map—four quadrants (Basic Themes, Motor Themes, Niche Themes, Emerging/Declining Themes). systems but are highly specialized. Lastly, \"Emerging or Declining Themes\" are those that represent the dynamic and changing nature of e-payment technology research, with new ideas coming to the fore and older ones becoming less relevant. Figure 8 provides the factorial analysis to identify clusters of closely related variables in e-payment technology convergence.