Classical communication channel

In quantum teleportation, Alice is given a state pm = ip)(ip whose identity is unknown to her. She may do anything she wishes to this state and then she communicates with Bob via only a classical communication channel. Bob s aim is to create a state pout which best resembles the original state. 

To close the loop, teleportation and indeed many other quantum communication protocols do not need a universal set of gates and do quite well with just those gates covered by the Gottesman-Knill theorem [Bartlett 2002], Although these protocols may be easily simulated, they have capabilities beyond classical communication channels - clearly simulation is not everything. 

Greenberger 1989 Greenberger 1990], Distributed entanglement thus allows to establish non-classical correlations between distant parties and can therefore be considered as a quantum analogue of the classical communication channel, a quantum communication channel. 

It is important to notice that for the teleport to be successfully implemented, a classical communication channel must be used, to send Alice s measurement results. Without that information Bob will never know that the state of his qubit has been changed. 

Abstract. Quantum key distribution algorithms use a quantum communication channel with quantum information and a classical communication channel for binary information. The classical channel, in aU algorithms to date, was required to be authenticated. Moreover, Lomo-naco [8] claimed that authentication is not possible using only quantum means. This paper reverses this claim. We design an algorithm for quantum key distribution that does authentication by quantum means only. Although a classical channel is still used, there is no need for the channel to be authenticated. The algorithm relies on two protected pubhc keys to authenticate the communication partner. 

Alice and Bob wish to establish a secret key, to be used henceforth to encrypt / decrypt messages. One session is required to establish a binary secret key, called secret, such that Alice and Bob are in consensus about the value of the secret key. The secret key secret consists of n bits, secret = 6162...6 . Technically, to perform the algorithm, Alice and Bob need a classical communication channel, an array of entangled qubit pairs, and two protected public keys. 

This property is even stronger in our improved algorithm with no classical communication presented in the Conclusion section. Here, the decision on how to measure a qubit (directly or with a Hadamard gate) is not made on a classical communication channel, but in private by Alice and Bob independently. 

A major surprise in the early days of quantum computing theory was that quantum error correction was possible at all it has been shown that if a qubit of quantum information is redundantly coded into several qubits, earors in quantum computation can be reduced just as they can be corrected in classical communications channels (Nielsen and Chuang, 2000). One certainty is that the operation of scalable quantum computers will rely heavily on earor correction. There is a threshold for error corrected continuous quantum computation. When errors at the single-qubit-level quantum operations are reduced below this threshold, quantum computation becomes possible. 

On the other hand, two classical bits have four possible sequences 00, 01, 10 or 11, each of them representing a possible message , which can be sent through a communication channel. Suppose that Alice wishes to send Bob the sequence 01. All she has to do is to apply the operator X on her qubit, of the entangled pair (say, the qubit a of the state ab)), transforming the state to ... 

Quantum key distribution protocols establish secret keys via insecure quantum and/or classical channels. Existing quantum key distribution algorithms generally use two communication channels between Alice and Bob a quantum channel which transmits qubits and a classical channel for classical binary information. The classical channel is used to communicate measurement strategy, or the basis for measurement, and to check for eavesdropping. 

The sales strategy needs to decide what product to be sold in which sales market representing the sales location in the value chain network. New markets needs to be evaluated for their attractiveness and the own competitive position with respect to existing products or the capabilities in the development of new products for the respective demand. Sales business rules include decisions on the strategic share of contracted business volumes vs. flexible spot business volumes. These business rules often depend on sales channels and frame contracts with customers. The sales strategy can be matched with classical marketing mix decisions on products, prices, promotion and communication, as well as sales channel decisions. 

C. Ruckes, U. Blank, K. Moller, J. Rieboldt, H. Lindemann, G. Munker, W. Clauss, and W. M. Weber. Amiloride-sensitive Na+ channels in human nasal epithelium are different from classical epithelial Na+ channels. Biochem Biophys Res Commun 237 488-491 (1997). 

An efficient way to implement the concept of QMFs was developed in 1989 by Mal-lat leading to the FWT, which requires only n operations for an -dimensional vector [56]. The Mallat algorithm is in fact a classical scheme known in the signal processing community as a two-channel subband coder. 

Mallat Algorithm is in fact a classical scheme known in the signal processing community as a two-channel subband coder. 

Secret key cryptography is the classical form of cryptography. Two candidates A and B that want to share secure information use the same key for encryption and decryption, which requires prior communication between A and B over a secure channel. 

N ote that to carry out the successful teleportation of a photon state, Alice had to communicate something to Bob by a classical channel (Eke a telephone). 

Note that all quantum key distribution algorithms mentioned above require that the classical channel be authenticated. Authentication is supposed to be done by classical means. The authenticated classical channel prevents Eve from masquerading as someone else and tamper with the communication. It was claimed by Lomonaco [8] that authentication is not possible in quantum... 

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