The security of traditional cryptography protocols is threatened by the emergence of quantum computing, which could in turn threaten the fundamentals of classical cryptography. Popular encryption schemes such as RSA, ECC, and Diffie-Hellman could potentially be broken by quantum algorithms, especially by Shor's and Grover's algorithms, which can solve computationally impossible problems for traditional computers. In this paper, the study focuses on the risks that Quantum Computing could pose to current cryptographic protocols, the identification of classical security protocols that are susceptible to quantum attacks, and the examination of the effectiveness of current cryptographic protocols against quantum threats. Attack vectors like replay attacks and Man in the Middle attacks are looked in a quantum context. Additionally, the need for and limitations of quantum protocols such as Quantum Key Distribution are considered in response to these new threats.