Fault tolerant deterministic secure quantum communication using logical Bell states against collective noise

This study proposes two novel fault tolerant deterministic secure quantum communication(DSQC) schemes resistant to collective noise using logical Bell states. Either DSQC scheme is constructed based on a new coding function, which is designed by exploiting the property of the corresponding logical Bell states immune to collective-dephasing noise and collective-rotation noise, respectively. The secret message can be encoded by two simple unitary operations and decoded by merely performing Bell measurements, which can make the proposed scheme more convenient in practical applications.Moreover, the strategy of one-step quanta transmission, together with the technique of decoy logical qubits checking not only reduces the influence of other noise existing in a quantum channel, but also guarantees the security of the communication between two legitimate users. The final analysis shows that the proposed schemes are feasible and robust against various well-known attacks over the collective noise channel.     

巡游电子系化合物La0.8Ce0.2(Fe1-xCox)11.4Si1.6的磁热效应

对制备的化合物La0.8Ce0.2(Fe1-xCox)11.4Si1.6(x=0.02,0.04,0.06)的相组成、巡游电子变磁转变(IEMT)特性和磁热效应(MCE)进行了研究。粉末X射线衍射结果表明,经1373 K真空退火处理7 d后,化合物La0.8Ce0.2(Fe1-xCox)11.4Si1.6(x=0.02,0.04,0.06)均为单相立方NaZn13型晶体结构。随着Co含量由x=0.02增加到x=0.06,样品的居里温度TC由207 K上升到277 K。在0~1.5 T磁场变化下,x=0.02,0.04,0.06时样品的最大磁熵变|ΔSM(T)|分别为40.17,12.60和7.65 J.kg-1.K-1,可见该化合物有巨大的磁熵变,而且随Co含量的增加最大磁熵变迅速减小。该化合物的巨大磁熵变来源于TC处的一级相变,以及在TC以上由磁场诱导IEMT,但由于Co原子对Fe原子的替代能够抑制变磁转变的发生,因此该系化合物最大磁熵变随Co含量的增加迅速减小。     

A Novel Deterministic Secure Quantum Communication Scheme with Einstein–Podolsky–Rosen Pairs and Single Photons

A novel deterministic secure quantum communication(DSQC)scheme is presented based on EinsteinPodolsky-Rosen(EPR)pairs and single photons in this study.In this scheme,the secret message can be encoded directly on the first particles of the prepared Bell states by simple unitary operations and decoded by performing the Bell-basis measurement after the additional classic information is exchanged.In addition,the strategy with two-step transmission of quantum data blocks and the technique of decoy-particle checking both are exploited to guarantee the security of the communication.Compared with some previous DSQC schemes,this scheme not only has a higher resource capacity,intrinsic efciency and total efciency,but also is more realizable in practical applications.Security analysis shows that the proposed scheme is unconditionally secure against various attacks over an ideal quantum channel and still conditionally robust over a noisy and lossy quantum channel.     

一种无密钥托管的移动IPv6网络匿名密钥分发协议

针对基于身份的密码体制IBE中固有的密钥托管问题,本文提出了一个移动IPv6网络环境中的无密钥托管匿名密钥生成机制与分发协议.该机制将节点身份认证和密钥生成与分发这两个过程分离,利用不可区分性匿名密文安全性在PKG不知道节点地址的情况下分发私钥给经过身份认证的节点,使得私钥生成中心或认证中心即使被单独攻破,攻击者也无法实现身份碰撞.可将身份认证中心部署于家乡服务器,而将PKG离线部署.经安全性分析,协议有效解决了移动IPv6网络中基于身份密码体制的密钥托管问题.     

一个人的“野蛮”战争周鸿神奋斗记

4月1日凌晨，知名互联网投资人蔡文胜在新浪微博中写道：“360上市这回事．让好多人明白了什么叫‘羡慕妒忌恨’!有木有？!有木有!!”360上市．让一些人睡不着觉，那是狂喜的投资人和360员工；360上市．也让另外一些人睡不着觉，那是“羡慕嫉妒恨”的竞争对手。正如一位互联网评论人所说的那样．360成功登陆纽交所。证明360免费模式得到了海外资本市场的认可．这是对360创新能力的肯定。然而，创新从来不是天上掉下来的，而是冲杀出来的。熟知中国互联网江湖的人都知道，偏执好斗的周鸿神绝对是一位绕不过的人物：多年来，他左奔右突，树敌无数，所过之处鸡犬不宁，硝烟弥漫。他是同行眼里心狠手辣的搅局者。投资人眼里藉以生财的摇钱树，网民心中第一个吃免费杀毒“螃蟹”的开山人：他一边开诚布公地与所有人合作．一边为了生存不惜与权威机构翻脸；因为年轻莽撞，他早早背上“流氓软件之父”的十字架．也曾因此反躬自省．发起打击流氓软件的全民运动。他是一个不创新毋宁死的理想主义者．更是一个不达目的不罢休的斗士。     

基于身份认证的安全量子中继器网络编码方案

本文将量子一次一密通信方法引入到量子中继器网络中,提出了基于身份认证的安全量子中继器网络编码方案.针对编码过程中存在的主动攻击问题,用一次一密的方式实现任意相邻节点通信过程中的身份认证,优化编码算法,最终在源节点与目的节点间生成量子纠缠态作为信道,构成量子隐形传态网络.方案分析表明,这种方案可以实现高可靠性、高安全性的远程量子通信.     

基于拟人化推理策略的行为模仿

本文从模仿机制的再现环节入手,采用知识使用和行动预见为主的拟人化推理策略,来实现有效的行为模仿.具体地,以模糊集合间的Hausdorff距离作为知识使用的尺度,导入知识半径到距离型模糊推理方法当中实现知识的选择使用;以预见控制的基本思想为指导,设计行动预见模型作为知识使用的高层决策,优化知识使用策略的参数.并以驾驶行为模仿为例,验证了拟人化推理策略对于动态知识使用的有效性,实现了即学即仿的模仿效果.     

分数阶记忆元件通用等效电路的设计

根据分数阶记忆元件之间的转换关系,设计了一种分数阶记忆元件通用等效电路。该等效电路在不改变电路拓扑结构的情况下,通过选择五个阻抗元件的类型,可以将任意一种接地型分数阶记忆元件转换为任意一种浮地型分数阶记忆元件。在仿真实验中,根据提出的通用等效电路,分别实现了三种分数阶记忆元件。对三种分数阶记忆元件的特性进行了分析,验证了该等效电路的正确性。     

Enhanced arbitrated quantum signature scheme using Bell states

We investigate the existing arbitrated quantum signature schemes as well as their cryptanalysis, including intercept- resend attack and denial-of-service attack. By exploring the loopholes of these schemes, a malicious signatory may success- fully disavow signed messages, or the receiver may actively negate the signature from the signatory without being detected. By modifying the existing schemes, we develop counter-measures to these attacks using Bell states. The newly proposed scheme puts forward the security of arbitrated quantum signature. Furthermore, several valuable topics are also presented for further research of the quantum signature scheme.     

一个人的“野蛮”战争——周鸿祎奋斗记

4月1日凌晨,知名互联网投资人蔡文胜在新浪微博中写道:"360上市这回事,让好多人明白了什么叫‘羡慕妒忌恨’!有木有?!有木有!!"360上市,让一些人睡不着觉,那是狂喜的投资人和360员工;360上市,也让另外一些人睡不着觉,那是"羡慕嫉妒恨"的竞争对手。正如一位互联网评论人所说的那样,360成功登陆纽交所,证明360免费模式得到了海外资本市场的认可,这是对360创新能力的肯定。然而,创新从来不是天上掉下来的,而是冲杀出来的。熟知中国互联网江湖的人都知道,偏执好斗的周鸿祎绝对是一位绕不过的人物:多年来,他左奔右突,树敌无数,所过之处鸡犬不宁,硝烟弥漫。他是同行眼里心狠手辣的搅局者,投资人眼里藉以生财的摇钱树,网民心中第一个吃免费杀毒"螃蟹"的开山人;他一边开诚布公地与所有人合作,一边为了生存不惜与权威机构翻脸;因为年轻莽撞,他早早背上"流氓软件之父"的十字架,也曾因此反躬自省,发起打击流氓软件的全民运动。他是一个不创新毋宁死的理想主义者,更是一个不达目的不罢休的斗士。