Updated: Jan 23, 2021
In today’s information society, data is one of the most valuable resources required by businesses to maintain a competitive advantage over others . Using cyberspace, data is carried across the world and into every corner of our lives. Technological advances and the expansion of cyberspace has brought data security to the forefront as the most critical problem facing the Internet in the future. As a result, businesses, as well as other actors must be able to maintain data secrecy by closely controlling who has access to it. To achieve this, data systems largely utilise cryptography, a method of protecting information through the use of codes and the scrambling of data which is only accessible to someone who can restore it to its original format. In current computer systems, cryptography is a strong inexpensive method of securing data, however, developments in the field of quantum computing threatens this but also provides an opportunity for the unconditional security offered by quantum cryptography to the Internet and data security as ever-increasing challenges arise in the future.
To explain the role that quantum cryptography could play in the near future it’s best to start with role of cryptography and how quantum computing effects it. As previously mentioned, cryptography disguises data and is only accessible by someone who can restore it to its original form. In a perfect scenario that person is known by the person who encrypted the data, and they are permitting the data recipient to access it. While classic cryptography has its exploitable flaws, , cryptography is still considered to be an effective security measure. However, the development of quantum computers in the last decade threatens to render cryptography as we know it obsolete. At their core, all computers rely on their ability to store and manipulate pieces of information known as bits. These bits are stored in a binary state as zeros and ones.
Quantum computers on the other hand, use quantum mechanics to manipulate information as quantum bits, known as qubits. Qubits are binary numbers like bits but have an additional state known as superposition which allows them to represent ones or zeros simultaneously. This state reduces the time it takes data to be analysed on quantum computers. This can be better understood in the following example, in 1997 IMB’s computer, Deep Blue, defeated chess champion Garry Kasparov by examining 200 million moves per second. In that second, a quantum computer would be able to calculate 1 trillion moves. So, how does this effect cryptography and the data it protects? By using quantum computers, encryptions that were previously thought to be unbreakable due to the time it would take to achieve it were cracked and proved to no longer be reliable in protecting data. In essence, quantum computers have changed the landscape of data security.
The development of quantum computers and the skill they’ve demonstrated in cracking classic cryptography highlights the need for new cryptosystems which can ensure the information security of cyberspace. By using quantum computers to develop encryptions there is an increased level of information security as well as additional advantages. Firstly, it offers unconditional security. In classic cryptography two kinds of cryptosystems can be used, asymmetric key cryptosystems and symmetric key cryptosystems. Both systems encrypt data and require users to decipher the encryption using a decryption key. These key systems can resist brute force attacks that from normal computers but not from quantum computers. But, if the key system in question was generated using a quantum computer it cannot be broken. This is because of a principle of quantum mechanics called the principle of uncertainty which states that a particle’s position cannot be determined and can exist in different places with different probabilities. By using this principle, keys can be randomly generated and shared between the data sender and the recipient. But what if communication between the two is being monitored by a third person? This risk is mitigated by quantum cryptography’s second advantage, it provides sniffing detection. If information is exchanged in a public channel it is possible for an attacker to eavesdrop on that channel without detection. However, through quantum communication this isn’t possible. By using the quantum no-cloning theory any eavesdropper would be detected. This theory explains that it is impossible to replicate an identical quantum state in another system which guarantees that any attacker who attempts to delete or damage quantum information will leave a trace. These characteristics of quantum computing and cryptography, unconditional security and sniffing detection ensures data security in cyberspace unlike classic cryptography.
It is clear that quantum computers are somewhat of a double-edged sword that threatens current data encryption while being its only saving grace. While the field of quantum cryptography has made substantial advances in the last decade it still faces challenges before its widespread implementation, including the need to develop more advanced hardware which would enable higher quality and longer transmission distances for quantum key exchange. However, developments in computer processing power coupled with the threat of obsolescence facing classic cryptography systems prove to be the force propelling the research and development of quantum cryptography. This technology has the potential to contribute significantly to security on a personal, commercial, and state level even if it only reaches a fraction of its expectations.