We present a novel quantum secret sharing scheme of secure direct communication and analyze its security.This scheme takes Einstein-Podolsky-Rosen(EPR)pairs in Bell states as quantum resources.In order to obtain thedi...We present a novel quantum secret sharing scheme of secure direct communication and analyze its security.This scheme takes Einstein-Podolsky-Rosen(EPR)pairs in Bell states as quantum resources.In order to obtain thedirect communication message,all agents only need to perform Bell measurements,not to perform any local unitary operation.The total efficiency in this scheme approaches 100%as the classical information exchanged is unnecessary except for the eavesdropping checks.展开更多
We present a quantum secret sharing scheme between multiparty (m members in Group 1) and multiparty (n members in Group 2), and analyze its security. This scheme takes EPR pairs in Bell states as quantum resources. In...We present a quantum secret sharing scheme between multiparty (m members in Group 1) and multiparty (n members in Group 2), and analyze its security. This scheme takes EPR pairs in Bell states as quantum resources. In order to obtain the shared key, all members only need to perform Bell measurements, rather than perform any local unitary operation. The total efficiency in this scheme approaches 100% as the classical information exchanged is not necessary except for the eavesdropping checks.展开更多
Steiner connected dominating set(SCDS)is a generalization of the famous connected dominating set problem,where only a specified set of required vertices has to be dominated by a connected dominating set,and known to b...Steiner connected dominating set(SCDS)is a generalization of the famous connected dominating set problem,where only a specified set of required vertices has to be dominated by a connected dominating set,and known to be NP-hard.This paper firstly modifies the SCDS algorithm of Guha and Khuller and achieves a worst case approximation ratio of(2+1/(m-1))H(min(△,k))+O(1),which outperforms the previous best result(c+1)H(min(△,k))+O(1)in the case of m≥1+1/(c-1),where c is the best approximation ratio for Steiner tree,A is the maximum degree of the graph,k is the cardinality of the set of required vertices,m is an optional integer satisfying 0≤m≤min(△,k)and H is the harmonic function.This paper also proposes another approximation algorithm which is based on a greedy approach.The second algorithm can establish a worst case approximation ratio of 2 ln(min(△,k))+O(1),which can also be improved to 2 lnk if the optimal solution is greater than c·e^2c+1/2(c+1).展开更多
We present an efficient controlled quantum perfect teleportation scheme. In our scheme, multiple senders can teleport multiple arbitrary unknown multi-qubit states to a single receiver via a previously shared entangle...We present an efficient controlled quantum perfect teleportation scheme. In our scheme, multiple senders can teleport multiple arbitrary unknown multi-qubit states to a single receiver via a previously shared entanglement state with the help of one or more controllers. Furthermore, our scheme has a very good performance in the measurement and operation complexity, since it only needs to perform Bell state and single-particle measurements and to apply Controlled-Not gate and other single-particle unitary operations. In addition, compared with traditional schemes, our scheme needs less qubits as the quantum resources and exchanges less classical information, and thus obtains higher communication efficiency.展开更多
In many models of all-optical routing, a set of communication paths in a network is given, and a wavelength is to be assigned to each path so that paths sharing an edge receive different wavelengths. The goal is to as...In many models of all-optical routing, a set of communication paths in a network is given, and a wavelength is to be assigned to each path so that paths sharing an edge receive different wavelengths. The goal is to assign as few wavelengths as possible, in order to use the optical bandwidth efficiently. If a node of a network contains a wavelength converter,any path that passes through this node may change its wavelength. Having converters at some of the nodes can reduce the number of wavelengths required for routing. This paper presents a wavelength converter with degree 4 and gives a routing algorithm which shows that any routing with load L can be realized with L wavelengths when a node of an all-optical ring hosts such a wavelength converter. It is also proved that 4 is the minimum degree of the converter to reach the full utilization of the available wavelengths if only one node of an all-optical ring hosts a converter.展开更多
基金Supported by the Key Project of the National Natural Science Foundation of China(No 90818005)the Research Program of Education Department of Anhui Province(No KJ2010A009)the 211 Project of Anhui University.
文摘We present a novel quantum secret sharing scheme of secure direct communication and analyze its security.This scheme takes Einstein-Podolsky-Rosen(EPR)pairs in Bell states as quantum resources.In order to obtain thedirect communication message,all agents only need to perform Bell measurements,not to perform any local unitary operation.The total efficiency in this scheme approaches 100%as the classical information exchanged is unnecessary except for the eavesdropping checks.
基金supported by the Major Research Plan of the National Natural Science Foundation of China (Grant No. 90818005)the National Natural Science Foundation of China (Grant Nos. 60903217, 60773032and 60773114)the Ph.D. Program Foundation of Ministry of Education of China (Grant No. 20060358014)
文摘We present a quantum secret sharing scheme between multiparty (m members in Group 1) and multiparty (n members in Group 2), and analyze its security. This scheme takes EPR pairs in Bell states as quantum resources. In order to obtain the shared key, all members only need to perform Bell measurements, rather than perform any local unitary operation. The total efficiency in this scheme approaches 100% as the classical information exchanged is not necessary except for the eavesdropping checks.
基金Supported by the National Natural Science Foundation of China under Grant No.60173048 on“Research on Routing and W avelength Assignment in W DM All-optical Networks”.
文摘Steiner connected dominating set(SCDS)is a generalization of the famous connected dominating set problem,where only a specified set of required vertices has to be dominated by a connected dominating set,and known to be NP-hard.This paper firstly modifies the SCDS algorithm of Guha and Khuller and achieves a worst case approximation ratio of(2+1/(m-1))H(min(△,k))+O(1),which outperforms the previous best result(c+1)H(min(△,k))+O(1)in the case of m≥1+1/(c-1),where c is the best approximation ratio for Steiner tree,A is the maximum degree of the graph,k is the cardinality of the set of required vertices,m is an optional integer satisfying 0≤m≤min(△,k)and H is the harmonic function.This paper also proposes another approximation algorithm which is based on a greedy approach.The second algorithm can establish a worst case approximation ratio of 2 ln(min(△,k))+O(1),which can also be improved to 2 lnk if the optimal solution is greater than c·e^2c+1/2(c+1).
基金supported by the Major Research Plan of the National Natural Science Foundation of China (Grant No.90818005)the National Natural Science Foundation of China (Grant Nos.61173187 and 61173-188)+1 种基金the Natural Science Foundation of Anhui Province (Grant No.11040606M141)the Research Program of Anhui Province Education Department (Grant No.KJ2010A009)
文摘We present an efficient controlled quantum perfect teleportation scheme. In our scheme, multiple senders can teleport multiple arbitrary unknown multi-qubit states to a single receiver via a previously shared entanglement state with the help of one or more controllers. Furthermore, our scheme has a very good performance in the measurement and operation complexity, since it only needs to perform Bell state and single-particle measurements and to apply Controlled-Not gate and other single-particle unitary operations. In addition, compared with traditional schemes, our scheme needs less qubits as the quantum resources and exchanges less classical information, and thus obtains higher communication efficiency.
文摘In many models of all-optical routing, a set of communication paths in a network is given, and a wavelength is to be assigned to each path so that paths sharing an edge receive different wavelengths. The goal is to assign as few wavelengths as possible, in order to use the optical bandwidth efficiently. If a node of a network contains a wavelength converter,any path that passes through this node may change its wavelength. Having converters at some of the nodes can reduce the number of wavelengths required for routing. This paper presents a wavelength converter with degree 4 and gives a routing algorithm which shows that any routing with load L can be realized with L wavelengths when a node of an all-optical ring hosts such a wavelength converter. It is also proved that 4 is the minimum degree of the converter to reach the full utilization of the available wavelengths if only one node of an all-optical ring hosts a converter.
