Papers by Keyword: Signature

Abstract: This paper presents a security of an attachable blind signature by Yeh et al. An eavesdropper is able to construct the attaches message m’ from an intercepted blind document. Consequently, attachable blind signature is breakable and cannot protect privacy.

Abstract: Private signature is a signature which provides signature privacy and restricted transference. Using the private scheme a user can sign a message in such a way that only a designated verifier can verify the signature. In some cases, the signer may want to preserve the privacy forever, which means that the initial verifier should not be able to convince anyone else of the fact that the signer signed the message. In some other cases, the signer may want to give the initial verifier the possibility to transfer his conviction to someone else, if desired. In this paper we first review the private signatures proposed by Javier Herranz, and point its drawback. Then we propose efficient private signature by combining a secure signature scheme and a non-interactive one-way key agreement.

Abstract: To extend the flexibility of data integrity verification method,adapted to the different verification environment, proposed an improved solution that can support multi-granularity.It organizes files into three kinds of granularity such as data blocks,data sub-blocks and basic-blocks,basic-block realize data gathered to form data sub-block.Sign in the data sub-block,using signature of the sub-block to generate signature of block. Improvement program can achieve the verification of data blocks and sub-blocks. Validation of data block can reduce the data traffic in the validation process,two particle combination can improve the overall efficiency.In the proposed layered merkel hash tree is put forward,the dynamic operation can be supported by the sub-block or the block.Securitycommunication performance analysis show that the improvement program is effective and has a better practicability

Abstract: Certificateless public key cryptography eliminates inherent key escrow problem in identity-based cryptography, and does not yet requires certificates as in the traditional public key infrastructure. Recently, Yu et al. propose a new certificateless signature scheme and their scheme offers shorter system parameters and higher computational efficiency than the previous schemes in the standard model. However, in this paper, we show Yu et al.'s certificateless signature scheme is vulnerable to malicious-but-passive KGC attack where a malicious KGC can forge valid signatures by embedding extra trapdoors in the system parameter.

Abstract: Partially blind signature is an important technique in secure electronic cash system. Recently, Zhang et al. presented the first certificateless partially blind signature scheme and constructed an electronic cash system based on this scheme. They claimed that their certificateless partially blind signature scheme is secure in the random oracle model. However, in this paper, we demonstrate the scheme is not secure. Our attack indicates that a malicious KGC in the electronic cash system based on Zhang et al.'s certificateless partially blind signature can forge valid electronic coins without being detected by the bank. It will result in loss of the bank.

Abstract: Electronic archive files have its advantage on speedy Operation relative to the archive file, however, it is hard to prevent tampering and safe for the file. The E-archives digital signature technology is very important for the Electronic information security. We analysis needs for the system, and design system solutions after the comparing various Signature and Encryption Technology, and propose function and design for the main module. Besides, there is the detailed design on the User registration, DEA file structure.

Abstract: Security and efficiency for using RSA signature scheme are critical requirements for many network applications. In this paper, we present a Game Model for RSA Signature Scheme (GMRS). By analyzing our model with information and game theory, we prove that the Nash-equilibrium is existent in GMRS. Accordingly, we propose an optimization scheme for updating the private key. The experiment result shows that, our scheme can significant promote the efficiency and ensure the security, even in the lowest risk-level case and for an adversary with unlimited computing power.

Abstract: The .NET platform is a very important commercial software platform, so understanding its protection and crack becomes very necessary. In the introduction, this article briefly introduces the platform, analyses the status quo of platform crack at home and abroad and what technology need to crack. Detailed descriptions of the crack .NET assembly principles and analytical methods for cracking tools are also described. Based on the existing methods, it provides an analogical method of crack, and it worked on a famous commercial software well.

Abstract: A verifiably encrypted signature scheme involves a signer, a verifier, and an adjudicator. It can convince a verifier that a given ciphertext is an encryption of signature on a given message. At a later stage on agreed or in case of dispute, the adjudicator can extract and give the signer's signature to the verifier. In existing verifiably encrypted signatures, the adjudicator is assumed to be a trusted third party who will not conspire with either of the two parties involved. Obviously, this assumption is naive. In this paper, we propose two new types of verifiably encrypted signature schemes. They can resolve the problem that the adjudicator may collaborate with the verifier. We also analyze the security of the proposed schemes.

Abstract: Ultrasonic signature of flaw is studied in the multipath scene, and a method is developed to localize the flaw by only single mono/bi-static measurement. A signal model based on the concept of multipath is built to construct flaw position, of which multipath scenarios are reviewed for signature of flaw depth. Multipath scenarios may be identified by direct path, which is relatively easy to be detected. Algebraic solution is proposed to solve the multipath equations to obtain the position of the flaw depth. Experiments show that the solution of the flaw depth is valid.