Encryption is the core of modern communication security. From the Enigma machine which was used during the World War II to HTTPS used today for the monetary and sensitive data transfers, Encryption is vital.
Any Encryption is prone to brute force attack no matter how secure it is. Given enough time and computing resources an encrypted text can be bruteforced and cracked to reveal its content. This is why crytographers created crytography algorithms which require a lot time and computing resources to crack. But they all used the constant thinking of that the encryption will be brute forced on a binary computing system which can go through cracking sequentially.
But with the introduction and investment into commercially available Quantum computing, a new threat is emerging to currently available encryption algorithms. As Quantum computing is not restricted to binary and can have multiple states simultaneously, In theory it will less time and computing resource to crack an encryption.
IBM's 50 Q Bit Quantum Computer (Source AOL)
Algorithms that are variations of Shor's Algorithm such as Asymmetric encryption (Public-Private key) are more vulnerable to bruteforcing using quantum computing as previously difficult math problems that underlie these methods will become trivially easy to crack almost irrespective of chosen key length. Asymmetric encryption is used in SSL/HTTPS and PGP which means in a time where quantum computing is widely adopted, they will be easy to crack and will impact your day to day online payments to logging in to your favourite social media account.
Experts are already aware of the implications and got together last September to find a solution for this upcoming problem.
In particular, They recommend McEliece cryptosystems as a good alternative to the current public-key infrastructure. Without relying on factoring large numbers, a McEliece system will hide your data by first wrapping it up with an error-correcting code (ECC) and then deliberately adding noise to it. Quantum computers, turn out not to be very useful in computing some types of ECCs.
Should you be worried now? Not really.
But by the time today's toddler enters University quantum computers can be as small as a laptop and can be readily available everywhere. That means the passwords stored in databases and credit card details going through the internet today can be easily read by a Man in the Middle. Thus we must be aware and prepared.