## 3 Attacks in Blockchain
### Detecting and Mitigating Malicious Blockchain Attacks
#### 3.3.3 Man-in-the-Middle (MITM) Attack
\begin{table}
\begin{tabular}{l l l} \hline \hline
**Attack** & **Detection Techniques** & **Security Measures (Mitigation)** & **References** \\ \hline \multirow{7}{*}{51\% Attack} & * Monitor unusual network behavior; & \\  & * Analyze mined blocks and block & * Use robust consensus mechanisms; & \\  & reorganization; & * Increase network size and decentralization; & \\  & Detect double spending and suspicious & * Apply checkpoints and diverse mining & [83; 84; 85] \\  & transactions; & communities. & \\  & Observe mining pool activities; & * Implement alerting mechanisms. & \\ \hline \multirow{7}{*}{Smart Contract Vulnerabilities} & * Static analysis (e.g., symbolic execution, control flow graphs); & * Adopt best design patterns and access control & \\  & Dynamic analysis (e.g., fuzz testing, runtime monitoring); & * Conduct regular security audits; & [57; 71; 72] \\  & Formal verification and code auditing. & * Use upgrade contracts and comprehensive & \\ \hline Double- & * Monitor transaction verification times; & * Increase confirmation times and block & \\  & Analyze block confirmation and ledger & consistency; & \\  & consistency; & * Use key-evolving cryptography; & [36; 59; 86] \\  & Detect suspicious fork creation. & * Disable unconfirmed connections. & \\ \hline \multirow{2}{*}{Race Attack} & * Monitor transaction broadcasts; & * Periodic transaction monitoring; & \\  & Insert observer nodes for suspicious activity. & * Deploy observer nodes for continuous & [46; 87] \\ \hline \multirow{2}{*}{Replay Attack} & * Detect duplicate transactions; & * Implement strong replay protection; & \\  & Analyze transaction history in forked chains. & * Use coin-splitting techniques; & [51; 58] \\ \hline \multirow{7}{*}{Sybil Attack} & * Monitor node reputation and activity; & * Restrict high-computing-power nodes; & \\  & Identify suspicious node behavior during & * Implement non-refundable deposits (e.g., currency burning); & [61; 62] \\  & PoW initiation. & * Use fidelity bonds and coin-age mechanisms. & \\ \hline \multirow{7}{*}{Eclipse Attack} & * Use anomaly detection tools; & * Implement timestamp-based protocols; & \\  & Run seeding and eliminate & * Use threat database models for detection; & [37; 66] \\  & exploitation windows. & * Enhance network load monitoring. & \\ \hline \multirow{7}{*}{Man-in-the-Middle Attack} & * Detect unusual network activity; & * Encrypt communication between nodes; & \\  & Check transaction discrepancies; & * Use multi-factor authentication for private key & \\ \cline{1-1}  & Monitor potentially malicious nodes. & * Employ public key infrastructure and & [74; 76] \\ \cline{1-1}  & & biometric authentication. & \\ \hline \multirow{7}{*}{Routing Attack} & * Monitor network traffic patterns; & * Secure routing protocols using digital & \\ \cline{1-1}  & Use reputation systems to identify malicious nodes. & * Apply distributed consensus mechanisms. & [88; 89] \\ \hline \hline \end{tabular}
\end{table} 
Table 2: A summarized overview of the detection and mitigation techniques for blockchain attacks.