## 3 Scheme Design
### Scheme Process
#### 3.2.1 Identity Registration: One-Time-Use Accounts  
In this scheme, in order to resist internal intrusions and improve identity privacy, all users' orders, payments, forwarding, and other services are completed through one-time-use accounts on the chain. The identity provider will first generate the one-time-use account for the user. A one-time-use account consists of a one-time public and private key. The concept of one-time public keys, as mentioned in Monero [38], is used to generate a decentralized identity (DID) that controls access and hides the association between addresses and real identities. \(G\) represents a public parameter that signifies a base point of an elliptic curve and \(Hash\) is a function that encodes points on an elliptic curve into a scalar, as shown in Table 1. The initial steps are dedicated to generating a one-time-use account. This computation can be performed by a third-party peer-to-peer tool or managed by the platform, which only provides the computation and transmission of these keys. The storage is typically generated locally or temporarily, and does not record any information related to the user's identity so this will protect identity privacy. The receiver and sender randomly generate private keys, denoted as \(k_{r},k_{s}\). Then, the receiver and sender disclose public keys to each other, denoted as \(K_{r}=k_{r}G,K_{s}=k_{s}G\). The receiver generates a random \(r_{r}\) to calculate \(R_{r}\) and sends \(R_{r}\) to the sender, as shown in Equation (1). \[R_{r}=r_{r}G \tag{1}\]  
After receiving \(R_{r}\), the sender generates a random number \(r_{s}\) and calculates the receiver's one-time public key \(K_{r1}\) which is shown in Equation (2). \[K_{r1}=Hash(r_{s}K_{r})G+K_{r} \tag{2}\]  
The sender calculates the one-time public key \(K_{s1}\) and obtains the \(K_{s1}\) as DID, which is shown in Equation (3). Only the sender has the private key \(sk_{s}\), which is shown in Equation (4). \[K_{s1}=Hash(k_{s}R_{r})G+K_{s} \tag{3}\]  
\[sk_{s}=Hash(k_{s}R_{r})+k_{s} \tag{4}\]  
The sender utilizes \(K_{s1}\) to authenticate to the logistics company that initiates the order and uses the private key to digitally sign the intended shipping address denoted as address-from. The sender specifies the receive as \(K_{r1}\) and then computes \(R_{s}\) and sends it to the receiver, as shown in Equation (5). \[R_{s}=r_{s}G\] \begin{table}
\begin{tabular}{c c} \hline \hline
**Notation** & **Descriptive** \\ \hline \(G\) & Parameters on elliptic curves \\ \(r_{r}\) & Random numbers on elliptic curves \\ \(R_{r}\) & The random number after multiplication with \\  & the common parameter G \\ \(Hash\) & Plaintext is mapped to a shorter binary string \\ \(K_{r}\),\(K_{s}\) & Receiver and sender public keys \\ \(k_{r}\),\(k_{s}\) & Receiver and sender’s private keys \\ \(K_{r1}\),\(K_{s1}\) & One-time public key from hash calculation \\ \(sk_{r}\),\(sk_{s}\) & Private key from the hash calculation \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Symbol descriptions. \[K^{\prime}_{r1}=Hash(k_{r}R_{s})G+K_{r}=K_{r1} \tag{6}\]  
Then, the receiver obtains \(R_{s}\) and calculates \(K^{\prime}_{r1}\), as shown in Equation (6). The receiver's DID is set to \(K_{r1}\). The receiver has its private key \(sk_{r}\), as shown in Equation (7). Therefore, the receiver uses \(K_{r1}\) to log into the logistics company and uses the private key to sign the recipient's address denoted as address-to. \[sk_{r}=Hash(k_{r}R_{s})+k_{r} \tag{7}\]  
The logistics company verifies the signatures of the sender and of the receiver, calculates the amount according to the address, and initiates the online collection. In addition, the distribution center can query address information. The distribution center point can, however, only query the next station address and they cannot obtain the complete logistics link. \(K_{r}\) is used to encrypt the information in the first and middle parts of the entire logistics, and \(K_{s}\) is used to encrypt the information in the middle and back parts of the logistics.