As quantum computing matures, it's going to bring unimaginable increases in computational power along with the systems we use to protect our data (and our democratic processes) will become even more vulnerable. It is often said that the power of quantum computer comes from the quantum parallelism, which means instead of processing each input one by one, processor process each input parallelly. Quantum mechanics allow us to do an operation on a superposition of all the possible inputs at the same time. The classical computers have enabled amazing things, but there are still some problems we can’t easily solve like-2^N(optimization problems where it grows exponentially). For transferring the information the protocols are very essential for security. An example is quantum key distribution, and its protocols are like -BB84, SARG04, B92 etc. Moreover, quantum cryptography has proved its standing against many weaknesses in the classical cryptography. One of these weaknesses is the ability to copy any type of information using a passive attack without an interruption, which is impossible in the quantum system.