# Blockchain for Future Wireless Networks: A Decade Survey
## 3 The Proposed Taxonomy for Security Attacks and Countermeasures
### Passive Attacks
In [123; 160], the author discussed the SQL injection prevention technique for the content delivery system, for which they used an obfuscation technique to secure their database queries. Furthermore, [PERSON] et al. [122] introduced a blockchain-enabled signature-based detection approach in a web attack detection application. This method detects web-based attacks and prevents SQL injection, cross-site scripting (XSS), and command injection techniques. Ref. [123] overcame the issue of SQL injection in the content delivery system. * Miscellaneous--Apart from the aforementioned attacks, there are some more security threats in WNs, which are as follows. * Impersonation attack--These attacks are performed by hacktivist and nation-state criminals that have a sophisticated agenda targeting critical organizations [126]. It can be provisioned by creating fake emails on the company site, social media, and e-commerce websites, and then the attackers can impersonate themselves by using those fake emails and accounts [161]. Moreover, they also create fake domains, unauthenticated accounts, and fraud applications to imperil the security schemes applied in the organizations. To prevent impersonation attacks, the user must avoid randomly clicking links on social media sites and emails, confirm the suspicious email request before any financial transaction, and verify a padlock icon next to a URL [162]. Ref. [163] proposed cross-technology impersonation attack prevention techniques for location-based services. Then, ref. [164] provided a solution to overcome the issue of voice impersonation attacks in smart devices. * Packet sniffing--This attack checks and analyze the data packets that are sent to the WNs [165]. Malicious users create data traffic and extract the packets using unencrypted mechanisms. Attackers illegally steal unencrypted data from companies, advertising agencies, and government agencies using a packet sniffing attack. Network monitoring and scanning activity, use of VPN, prevention of unsecured network, and encrypted messaging prevent packet sniffing attacks [166]. * Evil twinning--Through a wireless access point, the attacker can configure the existing WNs [165]. The access point of the attacker's system may have a strong signal than any other access point in the network so that the clients can choose the evil twin over the genuine access points [167]. In an evil twin attack, the malicious user creates a fake Wi-Fi network that steals the users' personal information, log activity, and credentials. To prevent evil twin attacks, visit only secure websites, protect AP using a private security key, and take care of connecting Wi-Fi hot-spots [168]. Blockchain permits authorized users to interact with each other in a verifiable manner, and it makes digital information to be shared, viewed and stored securely [169]. In that direction, many researchers have proposed their viable security and privacy solutions for WN-based applications. For instance, in [170], [PERSON] et al. proposed a blockchain-enabled CDMA/ CA model that handles scarcity of spectrum resource issues in the wireless industrial IoT applications. They introduced stochastic mode and double-spending attack. After that, [PERSON] et al. [171] introduced RAFT based consensus algorithm to prevent malicious jamming in IoT-based applications. [PERSON] et al. [172] discussed 5G security for the various applications such as SDN, NFV, etc. They proposed a 5G security model for securing the network and physical layer. In [173], [PERSON] et al. focused on the data tempering issue in the medical field. The proposed blockchain-based identity model is for e-health scenarios. In a similar direction, [PERSON] et al. [174] proposed blockchain-based architecture for UAVs that deal with reliability, connectivity, data privacy, and energy efficiency. [PERSON] et al. [175] analyzed edge cache network and presented blockchain-based 6G architecture for data tampering and eavesdropping. They utilized 6G edge caching and two-hop transmission for securing the transaction.