# A Blockchain-Based Decentralized Public Key Infrastructure Using the Web of Trust
## 8 Discussion
\begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Accomplishment** & **Approach** & **Existing Problem Addressed** \\ \hline Decentralized PKI & Create a blockchain-based decentralized PKI, utilizing a distributed trust model for enhanced security in the certification process & Centralized PKI limitations \\ \hline Build distributed trust model & Employ a web of trust model to build a key ring with trusted members to work as CAs & Single point of failure \\ \hline Introduce multiple introducers certificates & Empower multiple authorized introducers to verify and sign X.509 certificates & Single point of failure, MitM attacks \\ \hline Prioritized trusted introducers & Incorporating the concept of introducer depth helps limit the key ring’s size and gives precedence to the introducer in closer proximity to the ring owner & \\ \hline Minimal modifications on the browser side & Instead of changing the existing certificate format, we leverage the extension field in X.509\(\times\)3 to incorporate additional signatures & \\ \hline Information publicly visible & The nature of blockchain’s distributed and append-only data entry helps to keep the certificate information in the public ledger & Lack of transparency \\ \hline Faster revocation & Data transparency facilitates the detection of misbehaving CAs and the decentralized verification process and expedites the revocation of certificates & Convoluted revocation procedures \\ \hline Data integrity & Blockchain’s immutability ensures the integrity of stored data, making it tamper-proof & Data forgery attack \\ \hline Refine certification algorithm & Provide an enhanced algorithm and procedure to support multiple signatures in X.509\(\times\)3 & \\ \hline System implementation architecture & Provide complete implementation architecture with workflow and necessary technologies & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Comprehensive feature set of the proposed system. \begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline
**Schemes** & **Test Model** & **Conflective Format** & **Auto-Solable** & **Conflective Transparency** & **Resumer Side Unchanged** & **Decentralized Test** & **Advanced Verification** & **Probabilities Malicious Certification** & **No Controller CA** & **Monolum CA** & **Monolum CA** & **Activity** \\ \hline [PERSON] et al. [25] & Hierarchical & HybridX.509 & \(\times\) & \(\times\) & \(\times\) & PY & \(\times\) & \(\times\) & \(\times\) & \(\times\) & PY \\ \hline Controller [13] & Hierarchical & X.099 & \(\times\) & \(\times\) & \(\times\) & PY & \(\times\) & \(\times\) & \(\times\) & \(\times\) \\ \hline [PERSON] et al. [15] & Hierarchical & X.099 & \(\times\) & \(\times\) & \(\times\) & PY & \(\times\) & \(\times\) & \(\times\) & \(\times\) \\ \hline CRP(1) & Hierarchical & X.099 & \(\times\) & \(\times\) & \(\times\) & PY & \(\times\) & \(\times\) & PY & N/A \\ \hline CRP(1) & Hierarchical & Custom & \(\times\) & \(\times\) & \(\times\) & PY & \(\times\) & \(\times\) & \(\times\) & \(\times\) \\ \hline CRP(1) & WoT & Custom & \(\times\) & \(\times\) & \(\times\) & \(\times\) & PY & \(\times\) & \(\times\) \\ \hline CRP(1) & WoT & Custom & \(\times\) & \(\times\) & \(\times\) & \(\times\) & PY & \(\times\) & \(\times\) \\ \hline CRP(2) & WoT & Custom & \(\times\) & \(\times\) & \(\times\) & \(\times\) & PY & \(\times\) & \(\times\) \\ \hline CRP(3) & WoT & Custom & \(\times\) & \(\times\) & \(\times\) & \(\times\) & PY & \(\times\) & \(\times\) \\ \hline CRP(4) & Hierarchical & Custom & \(\times\) & \(\times\) & \(\times\) & PY & \(\times\) & \(\times\) & PY & \(\times\) \\ \hline Proposed system & WoT & X.509-A3 & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Feature comparison of blockchain-based PKIs. Note: \(\checkmark\)= supports the feature; \(\times\) = does not support the feature; PY = partially supports the feature; \(\text{N}/\text{A}\) = not applicable.