## 3 Results and Discussion
### The AVISPA Results  
In the OFMC and CL-AtSe back-ends, the SPAN tool simulated the proposed scheme for both cases (Case 1 and Case 2) using AVISPA tool. The following evaluations are carried out in our scheme in both cases:  
* Executability check on non-trivial HLPSL specifications: The proposed protocol model may not be completed due to modeling errors. As a result, the state unreachability of critical states in which an attack can occur, the AVISPA back-ends may not identify an attack, as mentioned in the protocol model. Consequently, an executability test is essential. Our initial HLPSL implementation shows that the executability test objectives in Figures 11-14 are met in both cases. * Replay attack check: The OFMC and CL-AtSe back-ends search for a passive intruder to determine whether authentic agents can execute the specified protocol. The simulation results shown in Figures 16 and 17 reveal that our scheme is secure against replay attacks in both cases. * Dolev-Yao model check: The AVISPA simulation, built on the OFMC and CLAtSe back-ends, detects man-in-the-middle and replay attacks. Figures 16 and 17 indicate indisputably that our scheme is secure when employed with these back-ends. features such as forward secrecy, untraceability, and multi-gateway supports. Furthermore, work of [PERSON] et al. (2021) is vulnerable to insider attacks, gateway impersonation attacks, DoS attacks, and sensor capture attacks. * Insider attack: The adversary gets the user's lost/stolen card and obtains the information \((HGW_{l}D,A_{th}^{*}),(FGW_{lD},A_{st}^{*}),TID_{i},Gen(.),Rep(.),h(. ),t,\tau,T_{i},S_{i}\) that is stored in the smart card. Even if the SA is trusted, information can be obtained \(PID_{i}\) and \(PWR_{i}\) by a malicious insider. Nevertheless, if the value \(T_{i}=h(U_{l}D)R\) is calculated with 1024-bit large secret number R; the attacker needs R to guess the user information \(U_{l}\), and \(U_{PW}\), which only the user Ui knows about it. Additionally, the attacker must know the biometric key data, if he/she wants to derive R, which is computationally infeasible to guess when compared to low-entropy passwords. Since the attacker cannot correctly guess \(U_{l}\), and \(U_{PW}\),, therefore, the proposed scheme is secure against insider attacks. Figure 17: The simulation results using OFMC and CL-AtS back-ends in Case 2. * Agriculture professional identity-guessing attack: As mentioned above, the SA knows the user information \(U_{ID}\), and \(U_{PW}\) during the registration phase and in case of the adversary with malicious insider attack, the SA knows about it while sending requests for registration. To obtain the identity of the user \(U_{ID}\) from \(PID_{i}=h(U_{ID}\parallel R)\), the attacker is required to know R. Furthermore, if the attackers intercept the messages \(M_{1}=[SN_{ID},TID_{i},CT_{i}]\) in the login phase,\(M_{2}=SN_{ID},CT_{j}\), \(M_{3}=SN_{ID},B_{i},Z_{i},TS_{3}\), during Case 1, and \(M_{5}=SN_{ID},CT_{f},M_{6}=SN_{ID},F_{i},Q_{i},TS_{5},M_{7}=SN_{ID},CT_{if}\) and \(M_{8}=SN_{ID},D_{i},J_{i},TS_{7}\) during the authentication procedure of Case 2. The attacker cannot correctly infer the user's identity since the \(TID_{i}\) is safeguarded using a one-way hash function. As a result, the proposed scheme is resistant to identity-guessing attacks. * Gateway impersonation attack: If the adversary attempts to drop the message \(M_{2}=SN_{ID},CT_{j}\) from the public channel during Case 1, where \(P_{i}=h(PID_{i}\parallel N_{j}\parallel N_{i}^{*}\parallel TS_{2})\), and \(CT_{j}=E_{SK_{i}}[HGW_{ID},SN_{ID},PID_{i},N_{i}^{*},N_{j},P_{i},TS_{2}]\), and tries to calculate the message \(M_{2}=SN_{ID},CT_{j}\) to send to the SNi. If the sensor accepts the message, the attacker will impersonate the news as a legitimate gateway. However, this is not possible in our proposed scheme since the letter is attached with a fresh timestamp \(TS_{2}\) and cannot pass the verification even if the adversary successfully generates a nonce \(N_{j}\).