Cryptography is based on "hard problems", something that is easy to solve one way, but hard the other way. Quantum computers provide algorithms that can severely break some of these (namely RSA with Shor's Algorithm https://en.wikipedia.org/wiki/Shor%27s_algorithm), and speed up all the others (namely Grovers Algorithm https://en.wikipedia.org/wiki/Grover%27s_algorithm). So it's not possible to simply increase bits to ensure algorithms are still secure, but it will work for most of them.

On the bright side there is also a branch of cryptography called post-quantum cryptography, which is a collection of algorithms designed to be more resistant in the face of quantum computers https://en.wikipedia.org/wiki/Post-quantum_cryptography.