This article examines the potential impact of quantum computing on cryptography as we currently have it. Initially, the fundamental role of cryptography in information security will be highlighted, mentioning classical cryptography and modern cryptography, as well as the Caesar and Vigenère ciphers, in addition to RSA, ECC and AES. Quantum algorithms such as Shor's and Grover's demonstrate abilities that could compromise the security of RSA, for example. To address these emerging issues, the article explores alternatives resistant to quantum attacks, framed in post-quantum cryptography. Obstacles to the adoption of these technologies will also be covered, such as compatibility with existing systems, highlighting the need for global collaboration. Important initiatives by governments, large companies and startups show the growing evolution of quantum computing, in terms of accessibility.