# Blockchain Implementation Method for Interoperability between CBDCs
## 5 Evaluation
### Comparison of Proposed Methods and Exchanges  
This section compares the proposed method with the cryptocurrency exchange. Cryptocurrency exchanges have both a centralized and decentralized exchange method. We compare the proposed method with the exchange's technical use of blockchain, Private Key rental, amount of fluidity, transaction liability, transaction target cryptocurrency, and cryptocurrency information management. Table 2 shows the comparison with the proposed method and the exchange. The technical use of blockchain uses the proposed method, while the decentralized exchange uses the blockchain to store transactions. Centralized exchanges use centralized storage instead of a blockchain. The use of blockchain technology can determine whether a transaction can proceed without an arbitrator. Decentralized exchanges disclose transaction details and technically guarantee trust. Centralized exchanges keep their transactions private and rely on trust in the exchanges. Private key rental is not required by the proposed method and distributed exchange. Private key rental is closely related to security. The centralized exchange receives the private key and operates the exchange. In high volumes, centralized exchanges are a security risk. Cryptocurrency security incidents typically occur on exchanges rather than on blockchains. The amount of fluidity has many centralized exchanges, with few proposal methods and decentralized exchanges. The amount and price of liquidity are challenging to establish a deal at the time you want. Nevertheless, the proposed method of transactions always requires the consensus of the central bank. Transaction liabilities are all different. Transaction liability is a legal entity that guarantees cryptocurrency. If there is a problem with the transaction, it is responsible for solving the problem and compensation. Centralized exchanges are the responsibility of the exchange. In the event of a problem, the exchange guarantees a settlement. The responsibility for decentralized exchange is not clear, or the decentralized exchange is responsible. The proposed method is the responsibility of the central bank as a transaction between groups. A centralized exchange is responsible for the transaction. The decentralized exchange technically guarantees the reliability of the transaction. However, if there is a problem with the transaction, the liability may be unclear. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Blockchain Name** & \begin{tabular}{c} **Target Block** \\ **Generation Time** \\ \end{tabular} & \begin{tabular}{c} **Difficult Change** \\ **Time** \\ \end{tabular} & \
\begin{tabular}{c} **Average Block** \\ **Generation Time** \\ \end{tabular} &
\begin{tabular}{c} **Support of User** \\ **Data Insertion** \\ \end{tabular} \\ \hline Bitcoin & The 180 s & 30 min & 538.40/0588 s & OP\_RETURN \\ Ethereum & The 60 s & Each block & 1183.796214 s & input \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Block generation time result of each blockchain. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Feature** & **Proposed Method** & \
\begin{tabular}{c} **Centralization** \\ **Exchange** \\ \end{tabular} &
\begin{tabular}{c} **Decentralized** \\ **Exchange** \\ \end{tabular} \\ \hline \hline Technical use of & Yes & No & Yes \\ blockchain & No & Yes & No \\ Private Key rental & No & Yes & No \\ Amount of fluidity & Low & High & Low \\ Transaction liability & Central Banks & Exchange & Unknown \\ Transaction target & & & or exchange \\ cryptocurrency & CBDC & ALL cryptocurrency & Same Hash function \\ Cryptocurrency & & & cryptocurrency \\ information & Yes (open) & Yes (close) & No \\ management & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Comparison of proposed methods and related works. Transaction target cryptocurrency is as follows. The proposed method can deal with CDBC, decentralized exchanges with the same hash function cryptocurrency, and centralized exchanges with all cryptocurrencies.