04-10-2017, 12:49 PM
Quantum cryptography is the science of exploiting quantum mechanical properties to perform cryptographic tasks. The best-known example of quantum cryptography is the quantum key distribution, which provides a theoretically secure solution to the key exchange problem. The currently used public key encoding algorithms and signature schemes (eg, RSA and ElGamal) can be broken by quantum adversaries. The advantage of quantum cryptography lies in the fact that it allows to complete several cryptographic tasks which are shown or conjectured to be impossible using only classical (ie non-quantum) communication. For example, it is impossible to copy coded data into a quantum state and the very act of reading coded data in a quantum state changes the state. This is used to detect spying in the distribution of the quantum key.
Quantum cryptography uses the Heisenberg uncertainty principle formulated in 1927, and the non-cloning theorem was articulated by Wootters and Zurek and Dieks in 1982. Werner Heisenberg discovered one of the fundamental principles of quantum mechanics: "In the moment in which the position of the electron, its moment can only be known to the magnitudes corresponding to that discontinuous change, so that the more precisely the position is determined, the less the moment is known, and vice versa "(Heisenberg 1927 : 174). This simply means that the observation of quanta changes their behavior, by measuring the speed of quanta we would affect it and change its position, if we want to find the position of a quant, we are forced to change its speed. , we can not measure the characteristics of a quantum system without changing it (Clark, nd) and we can not record all the characteristics of a quantum system before these characteristics are measured. The Non-cloning Theorem proves that it is impossible to create a copy of an arbitrary unknown quantum state. This makes unobserved listening impossible because it will be detected quickly, which will greatly enhance the security that the reported data remains private.
Quantum cryptography was first proposed by Stephen Wiesner, then at Columbia University in New York, who, in the early 1970s, introduced the concept of quantum conjugate encoding. His seminal document entitled "Conjugate Coding" was rejected by the IEEE Information Theory Society, but was finally published in 1983 in SIGACT News (15: 1 pp. 78-88, 1983). In this work he showed how to store or transmit two messages encoding them into two "observable conjugates", such as linear and circular polarization of light, so that either but not both can be received and decoded. He illustrated his idea with an unforgeable banknote design. In 1984, Charles H. Bennett of the Thomas J. Watson Research Center of IBM and Gilles Brassard of the Université de Montréal proposed a method for secure communication based on Wiesner's "observable conjugates", which is now called BB84. In 1991, Artur Ekert developed a different approach to the distribution of the quantum key based on the peculiar quantum correlations known as quantum entanglement.
The random rotations of polarization on both sides (generally called Alice and Bob) have been proposed in Kak's three-stage quantum cryptography protocol. In principle, this method can be used for continuous and unbreakable data encryption if individual photons are used. The basic polarization rotation scheme has been implemented.
The BB84 method is the basis of quantum key distribution methods. Companies that manufacture quantum cryptography systems include MagiQ Technologies, Inc. (Boston, Massachusetts, USA), ID Quantique (Geneva, Switzerland), QuintessenceLabs (Canberra, Australia) and SeQureNet (Paris, France).
Quantum cryptography uses the Heisenberg uncertainty principle formulated in 1927, and the non-cloning theorem was articulated by Wootters and Zurek and Dieks in 1982. Werner Heisenberg discovered one of the fundamental principles of quantum mechanics: "In the moment in which the position of the electron, its moment can only be known to the magnitudes corresponding to that discontinuous change, so that the more precisely the position is determined, the less the moment is known, and vice versa "(Heisenberg 1927 : 174). This simply means that the observation of quanta changes their behavior, by measuring the speed of quanta we would affect it and change its position, if we want to find the position of a quant, we are forced to change its speed. , we can not measure the characteristics of a quantum system without changing it (Clark, nd) and we can not record all the characteristics of a quantum system before these characteristics are measured. The Non-cloning Theorem proves that it is impossible to create a copy of an arbitrary unknown quantum state. This makes unobserved listening impossible because it will be detected quickly, which will greatly enhance the security that the reported data remains private.
Quantum cryptography was first proposed by Stephen Wiesner, then at Columbia University in New York, who, in the early 1970s, introduced the concept of quantum conjugate encoding. His seminal document entitled "Conjugate Coding" was rejected by the IEEE Information Theory Society, but was finally published in 1983 in SIGACT News (15: 1 pp. 78-88, 1983). In this work he showed how to store or transmit two messages encoding them into two "observable conjugates", such as linear and circular polarization of light, so that either but not both can be received and decoded. He illustrated his idea with an unforgeable banknote design. In 1984, Charles H. Bennett of the Thomas J. Watson Research Center of IBM and Gilles Brassard of the Université de Montréal proposed a method for secure communication based on Wiesner's "observable conjugates", which is now called BB84. In 1991, Artur Ekert developed a different approach to the distribution of the quantum key based on the peculiar quantum correlations known as quantum entanglement.
The random rotations of polarization on both sides (generally called Alice and Bob) have been proposed in Kak's three-stage quantum cryptography protocol. In principle, this method can be used for continuous and unbreakable data encryption if individual photons are used. The basic polarization rotation scheme has been implemented.
The BB84 method is the basis of quantum key distribution methods. Companies that manufacture quantum cryptography systems include MagiQ Technologies, Inc. (Boston, Massachusetts, USA), ID Quantique (Geneva, Switzerland), QuintessenceLabs (Canberra, Australia) and SeQureNet (Paris, France).