Architecture-Centric Evaluation of Blockchain-Based Smart Contract e-voting for National Elections

Scenario 1—Connections outside of the blockchain network are hampered by a Man-in-the-
middle attack. $$ 
Scenario 2—Vote verification introduces the risk of coercion.$$ 
Scenario 3—High volumes of traffic is affecting accessibility and reliability. 
Phase 
2 
7. 
Brainstorm and 
Prioritise 
Scenarios 
The discussion included both sets of stakeholder representatives to elicit new scenarios that 
the expert group may have thought of and to identify any other scenarios from an end-user, 
voters, perspective. The generated utility tree from Step 5, aided in the discussion and 
elicitation of a larger set of scenarios. 
8. 
Analyse 
Architectural 
Approaches 
Present Results 
This step is a reiteration of step 6 if the highest-ranked scenarios of the first iteration of step 6 
differ from the highest-ranked scenarios identified in step 7. In the case of our ATAM, the 
highest priority scenarios of step 6 remained the same. 
9 Present 
Results 
This is the step where the results of the evaluation are presented. From the result of the 
ATAM evaluation, the major trade-off is the aspect of vote validation. To forestall the 
possibility of voters’ coercion the vote validating nodes should be restricted to only secure 
locations. 
Figure 3. Process View—UML activity diagram of BANES. 
Figure 3.
Process View—UML activity diagram of BANES.
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Figure 4. Development View—UML component diagram of BANES. 
4.2. Use of Scenarios for evaluation of Business Drivers and Quality Attributes 
From the elicited requirements, the most important business drivers of national e-voting in 
South Africa are the need to (i) reduce the huge cost associated with the use of ballot papers, and the 
distribution of electoral materials; (ii) increase the transparency of the electoral process; (iii) have a 
faster procedure for efficient voting and counting; (iv) have credible results; (v) increase voters’ 
accessibility; (vi) minimise carbon footprint; (vii) reduce the costs expended on elections; and (viii) 
increase participation of voters. The panel of experts considered the attributes of security, 
performance, and functional suitability as deserving of the highest priority because of the identified 
core business drivers. Security deals with the ability of the system to mitigate threats that may be 
harmful to its operations, performance is concerned with the speed and accuracy of system 
operations, while functional suitability is assessed based on the level of auditability, availability, 
transparency, and verifiability of the system. We derived specific scenarios to assess these important 
attributes (see Table 3).