This work proposes an electronic payment architecture named Pure Wallet(PW), which extends the concept of Blockchain cryptocurrency for offline transactions. The process is divided into three steps. The first step requires the use of an Internet connection, to convert cryptocurrency into a token at the tokenmanager. The token manager initiates a transaction that requires the offline recipient to sign the transaction. These transactions are performed between electronic devices like mobile phones through a secure P2P (Peer communication) NFC(P) using technologies along the token in the sender's device. The financial value in the form of a token is encrypted by the sender and sent to the receiver's device. In the third step, the receiver converts the received token into cryptocurrency in the presence of an Internet connection by sending the information required to complete the transaction to the token manager. The goal is to propose an electronic payment architecture utilizing Blockchain, which will enable financial transactions without instant connection to the Internet. The Blockchain implementation in this work utilized an ETWCompatible smart contract. The result shows a successful transfer of value without an instant Internet connection.

The fundamental idea is to use tokens to create access rights for a specified amount of cryptocurrency. After generating these tokens, they can be exchanged off-chain, which is useful in a situation where internet connections are unavailable. Later, the generated token can be accessed when the Internet is available, and the corresponding cryptocurrency can be retrieved through a token return process on the on-chain. To ensure security, the token generation process utilizes a hash function that makes determining the input from the output difficult. The tokens are validated using their secondary and tertiary hash values to prevent malicious attacks. These hash values must match the predetermined values that allow the token to be redeemed for actual cryptocurrency. This validation process ensures that only the rightful owner of the token can exchange it for the cryptocurrency.

SWAP is implemented by accessing the smart contract of each decentralized exchange (DEX) pool, such as UniSwap and PancakeSwap, through the Web3 client. After initiating a SWAP transaction, its progress can be tracked using its transaction hash (Tx Hash). With this Tx Hash, users can monitor the transaction's processing status and the details of its information on the scan page of the relevant blockchain network.

Transfer of Asset Rights is a technology that allows tokens to be transferred offline, eliminating the need for an internet connection. This technology speeds up transactions and reduces the costs associated with exchanging cryptocurrency in the current blockchain environment. To ensure that the receiver has full control over the tokens, the token information must be transmitted to them and not kept by the sender. To achieve this, a 3-1-Handshake-based technology is implemented, which ensures that the token information is transferred accurately to the receiver.

The User Interface was designed to check the generated tokens, send each token, or return it to cryptocurrency, and allow it to be delivered through QR code on devices that cannot transmit Bluetooth. In the future, we plan to improve the compatibility of multiple accounts, other network tokens, and multiple tokens.

In the future, we plan to continue to expand compatibility with coins/tokens in multiple networks, and we will improve the portion where the current token is fixed to the amountset at the time of creation so that the flexible amount can be used. The existing method of paying with cryptocurrency in online shopping took a long time depending on the state of the cryptocurrency network, making it difficult to respond immediately, and it was coupled with tokenization to develop a real-time electronic payment solution. In addition, Pure Wallet currently presents a solution to cryptocurrency, but plans to cooperate with other teams to create an all-in-one solution by adding the API series based on the team's technology in the future. In the short term, it will include solutions such as Pure token, a decentralized network platform that instantly executes the exchange of cryptocurrency. The Pure team intends to lead the field of self-verify-supply-consumption in the fishing industry. In the long run, it will provide a transaction processor and customized services in combination with its own blockchain network Pure Chain and will expand to services that process transactions in Pure World.