scholarly journals A Provably Secure Proxy Signcryption Scheme Using Bilinear Pairings

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Nai-Wei Lo ◽  
Jia-Lun Tsai

As people in modern societies are busier than any human era and computer network has profound impact on how people work and live through fast and convenient information exchange, people need more help from each other to accomplish more work via network connections in limited period of time. Therefore, privilege delegation mechanism has become a necessary service in modern enterprises and organizations. Proxy signcryption scheme provides a secure privilege delegation mechanism for a person to delegate his privilege to his proxy agent to accomplish things. In 2010, Lin et al. had proposed an efficient signcryption scheme using bilinear pairings. However, we found that the proxy signcryption scheme of Lin et al. is vulnerable to the chosen warrant attack. A provably secure proxy signcryption scheme using bilinear pairings is introduced accordingly. In terms of performance efficiency, the proposed scheme is superior to other existing schemes. In addition, a new security model is proposed to describe proxy signcryption scheme; based on the security model we show that the proposed scheme is provably secure in terms of indistinguishability under adaptive chosen ciphertext attack (IND-CCA2), unforgeability under adaptive chosen message attack (EF-CMA), and unforgeability under adaptive chosen warrant attack (EF-CWA).

2018 ◽  
Vol 29 (06) ◽  
pp. 1063-1088 ◽  
Author(s):  
Caixue Zhou ◽  
Guangyong Gao ◽  
Zongmin Cui ◽  
Zhiqiang Zhao

Generalized ring signcryption (GRSC) can realize ring signature and ring signcryption functions with only one key pair and one algorithm. It is very useful for a system with a large number of users, or whose function may be changed, or with limited storage space. We give a formal definition and security model of GRSC in the certificate-based cryptosystem setting and propose a concrete scheme by using bilinear pairings. The confidentiality of our scheme can be proved under the GBDH and CDH assumptions and the unforgeability of our scheme can be proved under [Formula: see text] and CDH assumptions in the random oracle model, and what is more, our scheme has unconditional anonymity. Compared with other certificateless ring signcryption schemes that use bilinear pairings, it is a highly efficient one.


2021 ◽  
Author(s):  
Jean Belo KLAMTI ◽  
Anwar Hasan

A key encapsulation mechanism (KEM) that takes as input an arbitrary string, i.e., a tag, is known as tag-KEM, while a scheme that combines signature and encryption is called signcryption. In this paper, we present a code-based signcryption tag-KEM scheme. We utilize a code-based signature and a CCA2 (adaptive chosen ciphertext attack) secure version of McEliece's {encryption} scheme. The proposed scheme uses an equivalent subcode as a public code for the receiver, making the NP-completeness of the equivalent subcode problem be one of our main security assumptions. We then base the signcryption tag-KEM to design a code-based hybrid signcryption scheme. A hybrid scheme deploys an asymmetric- as well as a symmetric-key encryption. We give security analyses of both our schemes in the standard model and prove that they are secure against IND-CCA2 (indistinguishability under adaptive chosen ciphertext attack) and SUF-CMA (strong existential unforgeability under chosen message attack).


2021 ◽  
Author(s):  
Jean Belo KLAMTI ◽  
Anwar Hasan

A key encapsulation mechanism (KEM) that takes as input an arbitrary string, i.e., a tag, is known as tag-KEM, while a scheme that combines signature and encryption is called signcryption. In this paper, we present a code-based signcryption tag-KEM scheme. We utilize a code-based signature and a CCA2 (adaptive chosen ciphertext attack) secure version of McEliece's {encryption} scheme. The proposed scheme uses an equivalent subcode as a public code for the receiver, making the NP-completeness of the equivalent subcode problem be one of our main security assumptions. We then base the signcryption tag-KEM to design a code-based hybrid signcryption scheme. A hybrid scheme deploys an asymmetric- as well as a symmetric-key encryption. We give security analyses of both our schemes in the standard model and prove that they are secure against IND-CCA2 (indistinguishability under adaptive chosen ciphertext attack) and SUF-CMA (strong existential unforgeability under chosen message attack).


2017 ◽  
Vol 2017 ◽  
pp. 1-17 ◽  
Author(s):  
Caixue Zhou ◽  
Zhiqiang Zhao ◽  
Wan Zhou ◽  
Yuan Mei

Generalized signcryption (GSC) can be applied as an encryption scheme, a signature scheme, or a signcryption scheme with only one algorithm and one key pair. A key-insulated mechanism can resolve the private key exposure problem. To ensure the security of cloud storage, we introduce the key-insulated mechanism into GSC and propose a concrete scheme without bilinear pairings in the certificateless cryptosystem setting. We provide a formal definition and a security model of certificateless key-insulated GSC. Then, we prove that our scheme is confidential under the computational Diffie-Hellman (CDH) assumption and unforgeable under the elliptic curve discrete logarithm (EC-DL) assumption. Our scheme also supports both random-access key update and secure key update. Finally, we evaluate the efficiency of our scheme and demonstrate that it is highly efficient. Thus, our scheme is more suitable for users who communicate with the cloud using mobile devices.


2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Seth Alornyo ◽  
Kingsford Kissi Mireku ◽  
Mustapha Adamu Mohammed ◽  
Daniel Adu-Gyamfi ◽  
Michael Asante

AbstractKey-insulated encryption reduces the problem of secret key exposure in hostile setting while signcryption cryptosystem attains the benefits of digitally signing a ciphertext and public key cryptosystem. In this study, we merge the primitives of parallel key-insulation cryptosystem and signcryption with equality test to construct ID-based parallel key-insulated signcryption with a test for equality (ID-PKSET) in cloud computing. The construction prevent data forgery, data re-play attacks and reduces the leakage of secret keys in harsh environments. Our scheme attains the security property of existential unforgeable chosen message attack (EUF-CMA) and indistinquishable identity chosen ciphertext attack (IND-ID-CCA2) using random oracle model.


Author(s):  
Chanintorn Jittawiriyanukoon

<span>To secure a wealth of data traversing the computer network at your fingertips is compulsory. But when attack arises at various parts of the network it is difficult to protect, especially when each incident is investigated separately. Geography is a necessary construct in computer networks. The analytics of geography algorithms and metrics to curate insight from a security problem are a critical method of analysis for computer systems. A geography based representation is employed to highlight aspects (on a local and global level) of a security problem which are Eigenvalue, eccentricity, clustering coefficient and cliques. Network security model based on attack undirected geography (AUG) is familiarized. First, analysis based upon association rules is presented then the attack threshold value is set from AUG. The probability of an individual attack edge and associated network nodes are computed in order to quantify the security threat. The simulation is exploited to validate that results are effective.</span>


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Tzung-Her Chen ◽  
Ting-Le Zhu ◽  
Fuh-Gwo Jeng ◽  
Chien-Lung Wang

Although encryption and signatures have been two fundamental technologies for cryptosystems, they still receive considerable attention in academia due to the focus on reducing computational costs and communication overhead. In the past decade, applying certificateless signcryption schemes to solve the higher cost of maintaining the certificate chain issued by a certificate authority (CA) has been studied. With the recent increase in the interest in blockchains, signcryption is being revisited as a new possibility. The concepts of a blockchain as a CA and a transaction as a certificate proposed in this paper aim to use a blockchain without CAs or a trusted third party (TTP). The proposed provably secure signcryption scheme implements a designated recipient beforehand such that a sender can cryptographically facilitate the interoperation on the blockchain information with the designated recipient. Thus, the proposed scheme benefits from the following advantages: (1) it removes the high maintenance cost from involving CAs or a TTP, (2) it seamlessly integrates with blockchains, and (3) it provides confidential transactions. This paper also presents the theoretical security analysis and assesses the performance via the simulation results. Upon evaluating the operational cost in real currency based on Ethereum, the experimental results demonstrate that the proposed scheme only requires a small cost as a fee.


2013 ◽  
Vol 380-384 ◽  
pp. 2435-2438 ◽  
Author(s):  
Shu Rong Feng ◽  
Jiao Mo ◽  
Hua Zhang ◽  
Zheng Ping Jin

Certificateless short signature schemes can not only have the advantage of certificateless signature, but also provide a short signature size in communication. However, all existing certificateless short signature schemes only proven secure against a normal adversary which can only obtain the valid signature for the original public key rather than a super adversary which can obtain the valid signature for the replaced public key. Recently, Fan et al. proposed a certificateless short signature scheme which is very efficient, but we found it is still cannot against super adversary. In this paper, we first analysis their scheme, and then present an improved scheme which can against super adversaries. Furthermore, our scheme can provide both the strongest security level and the shortest signature size compared the existed provably secure certificateless short signature scheme.


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