# A Traceable and Verifiable Tobacco Products Logistics System with GPS and RFID Technologies
## 5 Discussion
### Communication Performance  
In Table 5, the communication performance was analyzed within every phase. The maximum transmission speed is 100 Mbps in a 4G environment, and the maximum transmission speed is 20 Gbps in a 5G environment [33].  
In our analysis, it was assumed that an ID message required 144 bits, a cipher message required at least 512 bits, and a signature message required 1024 bits. We assumed 512 bits of a cipher message by the minimum length of the message (2 IDs, 1 Timestamp, and 2 others) that is sent at the issuing ID and manufacture phase, which is 2 \(\times\) 144 bits + 1 \(\times\) 64 bits + 2 \(\times\) 80 bits = 512 bits.  
With the above definition, we used the transmitted message as the calculated communication cost. For example, in the logistics shipping phase, SHP sends two IDs, one cipher message, one signature to LG, then LG sends two IDs, one cipher message, and one signature to SHP for a response message. In total, it requires 4 \(\times\) 144 bits + 2 \(\times\) 512 bits + 2 \(\times\) 1024 bits. In a 4G environment, it only takes 36 \(\upmu\)s to transfer all the mes  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Phase** & **1 st Role** & **2 nd Role** & **3 rd Role** \\ \hline \multirow{3}{*}{Authentication Phase} & User A: & User B: & \\  & \(2T_{asy}\) + \(2T_{h}\) + \(2T_{all}\) + \(1T_{sub}\) + & \(2T_{asy}\) + \(2T_{h}\) + \(2T_{all}\) + \(1T_{sub}\) + & N/A \\  & \(4T_{mul}\) + \(3T_{dip}\) & \(3T_{mul}\) + \(3T_{div}\) & \\ \hline \multirow{3}{*}{Issuing and Manufacture} & Manufacturer: & IDI Issuer: & \multirow{3}{*}{Competent Authorities: \(2T_{asy}\) + \(2T_{h}\) + \(2T_{all}\) + \(1T_{sub}\) + \(4T_{sy}\) + \(4T_{hy}\) + \(4T_{sh}\) + \(4T_{sh}\) + \(4T_{sh}\) + \(4T_{sh}\) + \(6T_{mul}\) + \(6T_{div}\)} & \(3T_{mul}\) + \(3T_{div}\) \\ \hline \multirow{3}{*}{Logistics Phase (Shipping)} & Shipper: & Logistics: & \\  & \(2T_{asy}\) + \(2T_{h}\) + \(2T_{all}\) + \(1T_{sub}\) + & \(2T_{asy}\) + \(2T_{h}\) + \(2T_{all}\) + \(1T_{sub}\) + & N/A \\  & \(4T_{mul}\) + \(3T_{div}\) & \(3T_{mul}\) + \(3T_{div}\) & \\ \hline \multirow{3}{*}{Logistics Phase (Receiving)} & Logistics: & Recipient: & \\  & \(2T_{asy}\) + \(2T_{h}\) + \(2T_{all}\) + \(1T_{sub}\) + & \(2T_{asy}\) + \(2T_{h}\) + \(2T_{sh}\) + \(1T_{sub}\) + & N/A \\  & \(4T_{mul}\) + \(3T_{div}\) & \(3T_{mul}\) + \(3T_{div}\) & \\ \hline \multirow{3}{*}{Consumption Phase} & Consumer: & Retailer: & \multirow{3}{*}{Competent Authorities: \(2T_{asy}\) + \(2T_{h}\) + \(2T_{all}\) + \(1T_{sub}\) + \(4T_{mul}\) + \(3T_{div}\)} & \multirow{3}{*}{\(2T_{asy}\) + \(2T_{h}\) + \(2T_{all}\) + \(1T_{sub}\) + \(4T_{mul}\) + \(3T_{div}\)} & \multirow{3}{*}{\(3T_{mul}\) + \(3T_{div}\)} \\ \hline \hline \end{tabular} Notes: \(T_{asy}\): asymmetrical encryption/decryption; \(T_{h}\): a hash operation; \(T_{all}\): an additional operation; \(T_{mul}\): a subtraction operation. \(T_{mul}\): a multiplication operation; \(T_{mul}\): a division operation; \(T_{epi}\): an exponential operation  
\end{table}
Table 4: Computation costs of the proposed scheme.  
sages. In a 5G environment, the transmission time only needs 0.18 us to complete the authentication phase.