# A Blockchain Self-Sovereign Identity for Open Banking Secured by the Customer's Banking Cards
## 8 Conclusions and Future Work  
This work is a step toward adopting and emphasizing the SSI identity-sharing concept for the open banking paradigm. The proposed platform relies on usability and customer trust in using a payment card as tamper-resistant secure key storage for identity cryptographic operations and transactions performed on Ethereum Blockchain. SSBI provides a mobile app and a web-based trace component to manage communication and reporting to entities and controllers including third-party agencies, banks, and financial institutes. Per \begin{table}
\begin{tabular}{p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt}} \hline  & **KYC2 [18]** & **SCARB [21]** & **Onename.io [58]** & **PriFob [25]** & **Casper [24]** & **SSI Bank** & **BSBI [5]** & **SSBI** \\ \hline Banking KYC & Yes & No & No & No & Yes & No & Yes & Yes \\ \hline Utilize banking card for identity operations & No & No & No & No & Yes & No & Yes \\ \hline Recoverability & No & No & No &? & No & No & Yes & Yes \\ \hline Flexibility & No & Yes & No & Yes & Yes & Yes & Yes & Yes \\ \hline Portability & Yes & Yes & No & Yes & Yes & No & Yes & Yes \\ \hline Smart contract & Yes & No &? & Yes & No & No & Yes & Yes \\ \hline Interoperability & Yes & Yes & No & Yes & No & Yes & Yes & Yes \\ \hline Privacy protection & Yes & Yes & Yes & Yes & Yes & Yes & Yes & Yes \\ \hline Integrity confidentiality & Yes & No & Yes & Yes & Yes & Yes & Yes & Yes \\ \hline Accountability & Yes & Yes & No & Yes & Yes & Yes & Yes & Yes \\ \hline Selective disclosure & Yes & No & No & Yes & Yes & Yes & Yes & Yes \\ \hline Achieve high LoA & No & No & No & No & No & Yes & No & Yes \\ \hline Blockchain & Hyperledger Indy & Public ledger & Blockstack & Public permission Blockchain & Rahasak & Hyperledger Indy & Ethereum & Ethereum \\ \hline Consensus & Plenum & Byzantine protocol & Stacks & PoA/SoW & PoW & Plenum & PoW & PoA \\ \hline \end{tabular}
\end{table} 
Table 1: SSBI comparative analysis. sonal data are stored in the customer's mobile device while proofs are stored on Blockchain. Verifiable credentials are shared between the customers and the prover entities. SSBI benefits from the trusted banking card industry and security measures such as PCI-DSS standards. The payment card secures the issuance process and the audited life cycle ensures attestation, genuine smart chip keys, and certified installed applets. We assume that the customer holds at least one active bank account in the initial phase. The platform eliminates fraudulent banking calls and financial identity theft due to the strongly encrypted credentials and proofs. We reviewed the related solutions, proposed a solution, and described the framework architecture, layers, and components. In addition to the design objectives, we also describes the flow, including the initialization and authorization phases. This work provides a demonstrative proof-of-concept implementation based on banking Java Cards to sign the identity transactions on Ethereum Blockchain. We presented the integration of the banking card, personalization, applet development, and the flow to integrate with the banking issuance process. We presented a performance evaluation and security analysis, in addition to comparisons to related solutions. The preliminary evaluation of our implemented prototype, which exploits the use of a banking card with a Blockchain-based SSI solution, is highly impacted by the capacity and Blockchain configuration, such as size of the network, the number of nodes, and the expected load. The system showed a stable throughput, which complies with the requirements of our preliminary proof-of-concept implementation, but does not satisfy the real-world banking use case. The customer expects faster transaction execution. Hence, in future work, we will validate other options to improve the performance in terms of throughput and speed, with the aim of achieving a maximum of 15 s per transaction and a 1000 tps scale, which can fit with pilot real-world implementations.