# UAV-Based Privacy-Preserved Trustworthy Seamless Service Agility for NextG Cellular Networks
## 6 Security and Performance Analysis
### Privacy and Security Analysis  
The security analysis for our proposed authentication model shows immunity against the following security issues,  
1. _UE Privacy Leak:_ All authentication and communication messages toward either the UAV or the guest eNB in our proposed authentication mechanism use a different concealed UE ID, CID, instead of the actual IMEI/SUCI of the UE. That framework protects the UE from being identified, which prevents any leakage of private information. Furthermore, the only information shared with the UAV is whether the UE is a part of the inter-operator service or not. Therefore, since our proposed authentication for the inter-operator service agility feature does not expose any user's private information during or after handling the traffic to the guest operator base station, our proposed authentication does preserve privacy.
2. _Authentication of Origin_: The delegation phase securely provides the UAVs with an authentic warrant generated and signed by the home network core private key (origin authority), verifying the delegation source during the drone authentication stage. Furthermore, all other authentication messages involve a token key provided by the home network core (\(TTK_{i}\)) to ensure authenticity. Thus, any UAV proxy signature is based on the home network core, and then the proposed delegation-based scheme proves the authentication of the source.
3. _Authentication of Engaged Components_: The engaged components in the proposed mutual authentication mechanism are the UAV, the UE, and the guest-eNB. * The UAV: The proposed proxy signature keys generation is based on the UAV's (proxy signer) private key. Therefore, the verifier (i.e., the UE and guest-eNB) can identify the proxy signer identity (i.e., the UAV). * The UE: As a proxy signature verifier, the UE's authentication response includes an encrypted version of its concealed ID to verify the destination authenticity. * The guest-eNB: As a proxy signature verifier, the guest-eNB accommodation response includes an encrypted version of the guest-eNB ID as verification of destination authenticity. Therefore, the legitimacy of each component in the authentication scheme is mutually satisfied.
4. _Integrity Attacks_: Even if intercepted, the proxy signature messages are undeciberable since it is signed with both the home network's and the UAV's private keys. Moreover, all the authentication messages are encrypted with either the UAV's private or public keys, providing an extra layer of protection to exchanged data between the authentication parties. Therefore, any unauthorized attacker node intercepting the exchanged messages during the authentication or communicating phases will not be able to read, alter, fabricate, or modify the exchanged messages between the authentication parties. Thus, the proposed authentication scheme prevents message integrity.
5. _Replay Attack_: Each proxy signature message originating from a legitimate UAV is timestamped with \(T_{i}\) to ensure a fresh signature. Furthermore, all other authentication messages involve a token key provided by the home network core (\(TTK_{i}\)) with a timestamped nonce to ensure freshness. Therefore, Any illegitimate adversary intercepts and attempts to send a repeated or delayed version of the exchanged messages between the authenticated nodes will fail. Hence, our proposed authentication mechanism is resilient against any replay attack.
6. _IMSI Catchers and Impersonation Attacks_: Our proposed authentication mechanism is designed to protect exchange messages while sharing node IDs by encryption to prevent impersonators from reusing those IDs. The guest-eNB \(eNBID\) is accompanied by a token key \(TTK(i)\) to prevent accepting services from malicious attackers declaring using fake eNBIDs, i.e., IMSI Catchers. Furthermore, since we proved our proposed authentication scheme's authenticity of the origin and all engaged components, an impersonation attack is not possible.