If Du's claimed polynomial-time algorithm for 3-SAT is flawed, it has significant implications for the P vs. NP problem and its repercussions in computer science and cryptography. Firstly, the failure of the algorithm to correctly decide 3-SAT would not establish P = NP, challenging the fundamental complexity theory assumption. This could impact various fields relying on the P vs. NP conjecture, such as cryptography, where the security of many cryptographic protocols is based on the assumption that certain problems are computationally hard. If P were proven to equal NP, it would imply that these problems are solvable in polynomial time, potentially compromising the security of encrypted data and communication. Therefore, the correctness of algorithms claiming to solve NP-complete problems in polynomial time is crucial for the integrity of computational complexity theory and its applications in various domains.