Quantum Information Science

Modern information science is founded on the mathematical theories of communication and information established around 1948 by pioneers such as Norbert Wiener and Claude E. Shannon.
Today's society enjoys a wide range of conveniences thanks to the advances in this information technology. However, all scientific theories eventually reach the limits of their applicability and are succeeded by new paradigms. Information science, too, is destined to evolve into a next-generation discipline. Among the leading candidates for this role is quantum information science.

Quantum information science seeks to merge the principles of information theory with the fundamental laws of physics, aiming to create entirely new technologies. Its early foundations were laid around 1963, with initial research focused on formulating a theory of quantum communication that integrates the framework of Wiener and Shannon with the principles of quantum mechanics. This line of inquiry led to the development of the theory and applications of squeezed states, which sparked two decades of active discussion and continues today in the form of quantum teleportation research.

In the 1980s, quantum key distribution (QKD) was invented by combining cryptographic techniques with quantum communication. This is now known as the B884 protocol.
Unfortunately, it has become clear that such technologies face significant challenges in practical implementation within real-world systems.

Around the same time, research began on quantum computing, which applies quantum mechanics to the concept of computation. While realizing a quantum computer remains extremely difficult, its practical potential is still under investigation. As of now, quantum in formation science has not yet delivered the transformative results that were once anticipated.

In response to this situation, a new direction emerged around the year 2000: the integration of optical communication, mathematical cryptography, and quantum mechanics to establish a new generation of secure communication technologies for modern optical networks. This approach is grounded in the mathematical framework of quantum communication theory developed over two decades since the 1970s, combined with the mathematics of modern cryptography.

One notable outcome of this direction is the proposal of a new quantum cryptographic principle known as Keyed Communication in Quantum Noise (KCQ). Its implementation met hod. called the Y-00 protocol, has already been tested and operated on actual optical communication networks.

Quantum information science remains a young and evolving field. Whi le it holds great promise, excessive hype- such as claims that it will revolutionize computing or cryptography- should be approached with caution. There is a risk that such expectations may outpace reality. Researchers must remain grounded in the historical context and pursue this field with careful and critical judgment.

Reference: Osamu Hiro ta, "The Foundations of Quantum Information Science." Morikita Publishing.