Infrared (IR) image synthesis method of IR real background and modeled IR target

An infrared (IR) image synthesis method is proposed for the synthesis of a real IR background and modeled IR target, used as IR signatures, as well as a band-transformation between short wave IR (SWIR), middle wave IR (MWIR), and long wave IR (LWIR) in an IR imaging system simulation. IR target images are created by the RadThermIR software, an IR signature prediction software. Individual radiances for IR signatures, corresponding to the max/min temperatures of a real IR background and modeled IR target image, are calculated with Planck’s law. First, an IR background of an arbitrary wavelength band is transformed to one of the other wavelength bands with the temperature-radiance characteristics. And then, after adjusting the gray levels of the arbitrary IR target signatures based on their radiances for the wavelength band of the transformed IR background, these IR target and background signatures can be synthesized as one image for a specific wavelength band. The experimental results show that the modeled IR target images, such as a modeled helicopter and F16, can be synthesized on the IR background images of three IR wavelength bands. And we confirmed that IR background images of the three IR wavelength bands can diversely be synthesized with the modeled IR targets as the setting temperature of the target and background, the target distance, and the field of view (FOV) arbitrarily.     

基于身份的带凭证部分委托代理多重签名方案

本文基于椭圆曲线上的双线性对性质，提出了一个基于身份的带凭证部分委托代理多重签名方案，该方案具有强不可伪造性、强不可否认性、强可识别性和预防误用性．     

A New Signature Scheme with Shared Verification

1Introduction Withthedevelopmentofcomputerandnetworkcom municationtechnology,andwiththedifferenceofuser s demands,digitalsignaturetechniquesarebeingexpand edgreatly,fromthesinglesignature,singleverification modetothemulti user sone.Forexample,adocument sy…     

一种改进的可控制匿名性的离线电子现金系统

利用RSA盲签名算法和Schnorr一次数字签名算法,对Juels的电子现金方案[1]做了改进,提出一个新的可控制匿名性的电子现金系统。在用户向商家支付电子现金时,用户利用自己的秘密密钥对其将要支付的信息进行数字签名,解决了原方案中TTP(可信第三方)能冒充用户去花费用户的电子现金、他人获得合法用户的电子现金可盗用的问题,而且TTP使用公钥数字签名算法对可信标记签名,进一步增强了系统的安全性。最后对系统的安全性进行了分析。     

一种改进的ECC数字签名方案

利用组合公钥体制（CPK）的基本思想，结合椭圆曲线加密（ECC）算法，提出了一种改进的数字签名方案。该方案中，签名者使用双私钥对消息进行签名，并通过结合运用CPK和ECC的特点，实现了高效的密钥管理以及高可靠性，较传统数字签名方法有更高的安全性和方便性。最后，对该签名方案进行了安全性分析。     

Matrix presentations of braids and applications

We show that there exists a one-to-one correspondence between the class of certain block tridiagonal matrices with the entries or and the free monoid generated by generators and relation and give some applications for braids. In particular, we give new formulation of the reduced Alexander matrices for closed braids.

     

The -homology class of the Euler characteristic operator is trivial

On any manifold , the de Rham operator (with respect to a complete Riemannian metric), with the grading of forms by parity of degree, gives rise by Kasparov theory to a class , which when is closed maps to the Euler characteristic in . The purpose of this note is to give a quick proof of the (perhaps unfortunate) fact that is as trivial as it could be subject to this constraint. More precisely, if is connected, lies in the image of (induced by the inclusion of a basepoint into ).

     

On the Selection of Random Numbers in the EIGamal Algorithm

The EIGamal algorithm, which can be used for both signature and encryption, is of importance in public-key cryptosystems. However, there has arisen an issue that different criteria of selecting a random number are used for the same algorithm. In the aspects of the sufficiency, necessity, security and computational overhead of parameter selection, this paper analyzes these criteria in a comparative manner and points out the insecurities in some textbook cryptographic schemes. Meanwhile, in order to enhance security a novel generalization of the EIGamal signature scheme is made by expanding the range of selecting random numbers at an acceptable cost of additional computation, and its feasibility is demonstrated.