Why Quantum-Resistant Encryption Needs Quantum Key Distribution for Real Security

The idea behind the use of quantum computers to break encryption lies in the fact that the encryption keys used by current encryption methods depend on a secret key that is used to encrypt and decrypt the information that’s being protected. Those keys are long, random—or, more likely, almost random���numbers that are shared between the parties encrypting the information and the parties decrypting it. Theoretically, you can use a variety of mathematical processes to determine the key and then use the resulting key to decrypt the information. Until recently, the best defense for encrypted information was to make the key really long and really random. While a sufficiently powerful computer might be able to figure out the key eventually, it could require too much time to be useful. How much time? Perhaps the remaining age of the universe. But with the advent of quantum computing, things have changed. A modern quantum computer can carry out computational operations dramatically faster, perhaps several orders of magnitude faster, than the fastest imagined binary computer. To keep information encrypted requires the use of a quantum resistant encryption method and a really long encryption key, because the longer the key, the longer it takes to crack the encryption.