We suggest a method for transferring an unknown quantum state. In this method the sender Alice first applies a controlled-not operation on the particle in the unknown quantum state and an ancillary particle which she ...We suggest a method for transferring an unknown quantum state. In this method the sender Alice first applies a controlled-not operation on the particle in the unknown quantum state and an ancillary particle which she wants to send to the receiver Bob. Then she sends the ancillary particle to Bob. When Alice is informed by Bob that the ancillary particle is received, she performs a local measurement on her particle and sends Bob the outcome of the local measurement via a classical channel. Depending on the outcome Bob can restore the unknown quantum state, which Alice destroyed, on the ancillary particle successfully. As an application of this method we propose a quantum secure direct communication protocol. By introducing the decoy qubits the security of the scheme is guaranteed.展开更多
A two-step deterministic secure quantum communication （DSQC） scheme using blocks of three-qubit W state is proposed. In this scheme, the secret messages can be encoded by employing four two-particle unitary operatio...A two-step deterministic secure quantum communication （DSQC） scheme using blocks of three-qubit W state is proposed. In this scheme, the secret messages can be encoded by employing four two-particle unitary operations and directly decoded by utilizing the corresponding measurements in Bell basis or single-particle basis. Comparing with most previous DSQC protocols, the present scheme has a high total efficiency, which comes up to 50%. Apart from this, it has still the advantages of high capacity as each W state can carry two bits of secret information, and high intrinsic efficiency because almost all the instances are useful. Furthermore, the security of this communication can be ensured by the decoy particle checking technique and the two-step transmitting idea.展开更多
In the era of over communications and hyper concurrency, people are overloaded with the offer of information, ideas, products, and services. Information is easy and unbelievable prompt available all over the world. Cu...In the era of over communications and hyper concurrency, people are overloaded with the offer of information, ideas, products, and services. Information is easy and unbelievable prompt available all over the world. Customers, concurrency, and innovators have immediate access to each other changes in technology, especially those in informatics and technology of communication are transforming the era of informatics to the era of knowledge. The aim of this paper is to make an overview of the most up-to-date novelties in technology, especially those that were enabled by ICT, as well as to direct to some of the potential of the future evolution in business process that is open to the innovations.展开更多
The paper focuses on the manifestations, causes, and consequences of the failure of so-called public service media, especially in the field of news and journalism. Those media that, unlike private media, are funded fr...The paper focuses on the manifestations, causes, and consequences of the failure of so-called public service media, especially in the field of news and journalism. Those media that, unlike private media, are funded from public sources. The public service, which citizens are obliged to pay through taxes or direct fees, is supposed to provide quality information, to produce and to disseminate content that satisfies the democratic, cultural, and social needs of the society, with a task at hand to preserve media pluralism. The major obligation of public service media is usually for them to provide objective, validated, and balanced information for people, so they can choose freely where they stand on any given issue. However, examples of the failures of two public service media operating in the Central European Czech Republic, Czech Radio （？Ro）, and Czech Television （？T）, as well as the failures of the statutory control boards of these media, show that the required high quality public service prescribed by law, especially in the field of news and journalism and other programs, is not always kept. Public service media may be partisan and apply elements of modern censorship. This is a censorship that the law of the public service media does not impose and does not allow to carry out. Such censorship, which is a result of unilateral subordination of the influence of specific political parties, interest groups, and opinion streams, is reflected in information manipulation, purposeful agenda development, selection of information and information sources, spiral of silence, in the preference of some political parties, partisan, interest interpretation, and adaptation of reality in broadcasting.展开更多
基金The project supported by the National Natural Science Foundation of China under Grant No. 10671054 and the Natural Science Foundation of Hebei Province under Grant Nos. A2004000141 and A2005000140
文摘We suggest a method for transferring an unknown quantum state. In this method the sender Alice first applies a controlled-not operation on the particle in the unknown quantum state and an ancillary particle which she wants to send to the receiver Bob. Then she sends the ancillary particle to Bob. When Alice is informed by Bob that the ancillary particle is received, she performs a local measurement on her particle and sends Bob the outcome of the local measurement via a classical channel. Depending on the outcome Bob can restore the unknown quantum state, which Alice destroyed, on the ancillary particle successfully. As an application of this method we propose a quantum secure direct communication protocol. By introducing the decoy qubits the security of the scheme is guaranteed.
基金Supported by the Key Project of the Education Department of Anhui Province under Grant No.KJ2010A323the Talent Project of the Anhui Province for Outstanding Youth under Grant Nos.2009SQRZ190,2010SQRL186,2010SQRL187 and 2011SQRL147the Natural Science Research Programme of the Education Department of Anhui Province under Grant No.KJ2009B018Z
文摘A two-step deterministic secure quantum communication （DSQC） scheme using blocks of three-qubit W state is proposed. In this scheme, the secret messages can be encoded by employing four two-particle unitary operations and directly decoded by utilizing the corresponding measurements in Bell basis or single-particle basis. Comparing with most previous DSQC protocols, the present scheme has a high total efficiency, which comes up to 50%. Apart from this, it has still the advantages of high capacity as each W state can carry two bits of secret information, and high intrinsic efficiency because almost all the instances are useful. Furthermore, the security of this communication can be ensured by the decoy particle checking technique and the two-step transmitting idea.
文摘In the era of over communications and hyper concurrency, people are overloaded with the offer of information, ideas, products, and services. Information is easy and unbelievable prompt available all over the world. Customers, concurrency, and innovators have immediate access to each other changes in technology, especially those in informatics and technology of communication are transforming the era of informatics to the era of knowledge. The aim of this paper is to make an overview of the most up-to-date novelties in technology, especially those that were enabled by ICT, as well as to direct to some of the potential of the future evolution in business process that is open to the innovations.
文摘The paper focuses on the manifestations, causes, and consequences of the failure of so-called public service media, especially in the field of news and journalism. Those media that, unlike private media, are funded from public sources. The public service, which citizens are obliged to pay through taxes or direct fees, is supposed to provide quality information, to produce and to disseminate content that satisfies the democratic, cultural, and social needs of the society, with a task at hand to preserve media pluralism. The major obligation of public service media is usually for them to provide objective, validated, and balanced information for people, so they can choose freely where they stand on any given issue. However, examples of the failures of two public service media operating in the Central European Czech Republic, Czech Radio （？Ro）, and Czech Television （？T）, as well as the failures of the statutory control boards of these media, show that the required high quality public service prescribed by law, especially in the field of news and journalism and other programs, is not always kept. Public service media may be partisan and apply elements of modern censorship. This is a censorship that the law of the public service media does not impose and does not allow to carry out. Such censorship, which is a result of unilateral subordination of the influence of specific political parties, interest groups, and opinion streams, is reflected in information manipulation, purposeful agenda development, selection of information and information sources, spiral of silence, in the preference of some political parties, partisan, interest interpretation, and adaptation of reality in broadcasting.
