The concept of proxy signature introduced by Mambo, Usuda, and Okamoto allows a designated person, called a proxy signer, to sign on behalf of an original signer in 1996. However, most existing proxy signature schemes...The concept of proxy signature introduced by Mambo, Usuda, and Okamoto allows a designated person, called a proxy signer, to sign on behalf of an original signer in 1996. However, most existing proxy signature schemes does not support nonrepudiation. In this paper, we propose two secure nonrepudiable proxy signature schemes, which overcome disadvantages of M U O and K P W proxy signature schemes, respectively. The schemes proposed can withstand public key substitution attack and forge attack. In addition, our new schemes have some other advantages such as proxy signature key generation and updating using insecure channels. Our approach can also be applied to other ElGamal like proxy signature schemes.展开更多
In this study, the author has designed new verifiable (t, n) threshold untraceable signature schemes. The proposed schemes have the following properties: ( 1 ) Verification: The shadows of the secret distributed by th...In this study, the author has designed new verifiable (t, n) threshold untraceable signature schemes. The proposed schemes have the following properties: ( 1 ) Verification: The shadows of the secret distributed by the trusted center can be verified by all of the participants; (2) Security: Even if the number of the dishonest member is over the value of the threshold, they cannot get the system secret parameters , such as the group secret key, and forge other member's individual signature; (3) Efficient verification: The verifier can verify the group signature easily and the verification time of the group signature is equivalent to that of an individual signature; (4) Untraceability: The signers of the group signature cannot be traced.展开更多
miRNAs are a class of small, ∽22nt, non-coding RNAs that negatively regulate gene expression at the posttranscriptional level. They play profound and pervasive roles in manipulating gene expression involved in cell d...miRNAs are a class of small, ∽22nt, non-coding RNAs that negatively regulate gene expression at the posttranscriptional level. They play profound and pervasive roles in manipulating gene expression involved in cell development, proliferation and apoptosis in various eukaryotes, which, in theory, could provide an access to many human diseases in theory. Recent evidence demonstrates that aberrant miRNA expression is a hallmark of tumor development, revealing that miRNA genes could function as potential oncogenes and repressors in the human body. miRNAs can affect tumorigenesis mainly by interrupting the cell cycle at the cellular level and by interacting with signaling, oncogenes and with the response to environmental factors at the molecular level. The established miRNA expression signature could be a potent tool to diagnose and treat human cancers in the future.展开更多
低速率分布式拒绝服务(LDDoS,low-rate distributed denial of service)攻击是一种新型的DDoS攻击方式。LDDoS具有流量小和隐蔽性强的特点,现有的DDoS攻击检测方法不能正确发现LDDoS攻击流量。根据LDDoS攻击流量呈现周期性的特点,采用...低速率分布式拒绝服务(LDDoS,low-rate distributed denial of service)攻击是一种新型的DDoS攻击方式。LDDoS具有流量小和隐蔽性强的特点,现有的DDoS攻击检测方法不能正确发现LDDoS攻击流量。根据LDDoS攻击流量呈现周期性的特点,采用缓存队列占有率统计的方法,重点研究了受害目标路由器的缓存队列,分别统计分析了正常和攻击流量的占有率,并在NS-2环境中进行了仿真实验,成功提取了LDDoS攻击流量上的2个特征,提高了LDDoS攻击的检测率。展开更多
为了使学习者更深入的了解数字证书的原理及应用,完善实验室数字证书应用教学系统,文章以Java为开发语言,以Microsoft SQ L Server2008为数据管理平台,开发了该数字证书系统,实现了数字证书申请、数字证书签发与销毁、数字证书挂失、数...为了使学习者更深入的了解数字证书的原理及应用,完善实验室数字证书应用教学系统,文章以Java为开发语言,以Microsoft SQ L Server2008为数据管理平台,开发了该数字证书系统,实现了数字证书申请、数字证书签发与销毁、数字证书挂失、数字证书加密及数字证书的数字签名等功能。该系统的应用不仅可以很好地解决网络应用中存在的信息泄露、窃听和用户抵赖等问题,同时还可以让使用者更快、更直接地了解数字证书技术。展开更多
Certificateless public key cryptography is a new paradigm introduced by Al-Riyami and Paterson.It eliminates the need of the certificates in traditional public key cryptosystems and the key escrow problem in IDentity-...Certificateless public key cryptography is a new paradigm introduced by Al-Riyami and Paterson.It eliminates the need of the certificates in traditional public key cryptosystems and the key escrow problem in IDentity-based Public Key Cryptography(ID-PKC).Due to the advantages of the certificateless public key cryptography,a new efficient certificateless pairing-based signature scheme is presented,which has some advantages over previous constructions in computational cost.Based on this new signature scheme,a certificateless blind signature scheme is proposed.The security of our schemes is proven based on the hardness of computational Diffie-Hellman problem.展开更多
The infrared radiation signature of the plume from solid propellants with different energy characteristics is not the same. Three kinds of double-base propellants of different energy characteristics are chosen to meas...The infrared radiation signature of the plume from solid propellants with different energy characteristics is not the same. Three kinds of double-base propellants of different energy characteristics are chosen to measure the infrared spectral radiance from 1000 cm 1 to 4500 cm 1 of their plumes. The radiative spectrum is obtained in the tests. The experimental results indicate that the infrared radiation of the plume is determined by the energy characteristics of the propellant. The radiative transfer calculation models of the exhaust plume for the solid propellants are established. By including the chemical reaction source term and the radiation source term into the energy equation, the plume field and the radiative transfer are solved in a coupled way. The calculated results are consistent with the experimental data, so the reliability of the models is confirmed. The temperature distribution and the extent of the afterburning of the plume are distinct for the propellants of different energy characteristics, therefore the plume radiation varies for different propellants. The temperature of the fluid cell in the plume will increase or decrease to some extent by the influence of the radiation term.展开更多
文摘The concept of proxy signature introduced by Mambo, Usuda, and Okamoto allows a designated person, called a proxy signer, to sign on behalf of an original signer in 1996. However, most existing proxy signature schemes does not support nonrepudiation. In this paper, we propose two secure nonrepudiable proxy signature schemes, which overcome disadvantages of M U O and K P W proxy signature schemes, respectively. The schemes proposed can withstand public key substitution attack and forge attack. In addition, our new schemes have some other advantages such as proxy signature key generation and updating using insecure channels. Our approach can also be applied to other ElGamal like proxy signature schemes.
文摘In this study, the author has designed new verifiable (t, n) threshold untraceable signature schemes. The proposed schemes have the following properties: ( 1 ) Verification: The shadows of the secret distributed by the trusted center can be verified by all of the participants; (2) Security: Even if the number of the dishonest member is over the value of the threshold, they cannot get the system secret parameters , such as the group secret key, and forge other member's individual signature; (3) Efficient verification: The verifier can verify the group signature easily and the verification time of the group signature is equivalent to that of an individual signature; (4) Untraceability: The signers of the group signature cannot be traced.
基金the National Basic Research Program of China (2004CB1175004) and the National Natural Science of Foundation of China, No. 30025034
文摘miRNAs are a class of small, ∽22nt, non-coding RNAs that negatively regulate gene expression at the posttranscriptional level. They play profound and pervasive roles in manipulating gene expression involved in cell development, proliferation and apoptosis in various eukaryotes, which, in theory, could provide an access to many human diseases in theory. Recent evidence demonstrates that aberrant miRNA expression is a hallmark of tumor development, revealing that miRNA genes could function as potential oncogenes and repressors in the human body. miRNAs can affect tumorigenesis mainly by interrupting the cell cycle at the cellular level and by interacting with signaling, oncogenes and with the response to environmental factors at the molecular level. The established miRNA expression signature could be a potent tool to diagnose and treat human cancers in the future.
文摘低速率分布式拒绝服务(LDDoS,low-rate distributed denial of service)攻击是一种新型的DDoS攻击方式。LDDoS具有流量小和隐蔽性强的特点,现有的DDoS攻击检测方法不能正确发现LDDoS攻击流量。根据LDDoS攻击流量呈现周期性的特点,采用缓存队列占有率统计的方法,重点研究了受害目标路由器的缓存队列,分别统计分析了正常和攻击流量的占有率,并在NS-2环境中进行了仿真实验,成功提取了LDDoS攻击流量上的2个特征,提高了LDDoS攻击的检测率。
文摘为了使学习者更深入的了解数字证书的原理及应用,完善实验室数字证书应用教学系统,文章以Java为开发语言,以Microsoft SQ L Server2008为数据管理平台,开发了该数字证书系统,实现了数字证书申请、数字证书签发与销毁、数字证书挂失、数字证书加密及数字证书的数字签名等功能。该系统的应用不仅可以很好地解决网络应用中存在的信息泄露、窃听和用户抵赖等问题,同时还可以让使用者更快、更直接地了解数字证书技术。
基金the National Natural Science Foundation of China (No.60673070)the Natural Science Foundation of Jiangsu Province (No.BK2006217)the Open Project of the Key Lab. on Computer Networks and Information Security (Xidian University) of Ministry of Education of China(No.20040105)
文摘Certificateless public key cryptography is a new paradigm introduced by Al-Riyami and Paterson.It eliminates the need of the certificates in traditional public key cryptosystems and the key escrow problem in IDentity-based Public Key Cryptography(ID-PKC).Due to the advantages of the certificateless public key cryptography,a new efficient certificateless pairing-based signature scheme is presented,which has some advantages over previous constructions in computational cost.Based on this new signature scheme,a certificateless blind signature scheme is proposed.The security of our schemes is proven based on the hardness of computational Diffie-Hellman problem.
基金the National Natural Science Foundation of China(Grant No.11072032)
文摘The infrared radiation signature of the plume from solid propellants with different energy characteristics is not the same. Three kinds of double-base propellants of different energy characteristics are chosen to measure the infrared spectral radiance from 1000 cm 1 to 4500 cm 1 of their plumes. The radiative spectrum is obtained in the tests. The experimental results indicate that the infrared radiation of the plume is determined by the energy characteristics of the propellant. The radiative transfer calculation models of the exhaust plume for the solid propellants are established. By including the chemical reaction source term and the radiation source term into the energy equation, the plume field and the radiative transfer are solved in a coupled way. The calculated results are consistent with the experimental data, so the reliability of the models is confirmed. The temperature distribution and the extent of the afterburning of the plume are distinct for the propellants of different energy characteristics, therefore the plume radiation varies for different propellants. The temperature of the fluid cell in the plume will increase or decrease to some extent by the influence of the radiation term.
