Identity-based Public Key Cryptosystem Research Articles

Hierarchical Identity-Based Authenticated Encryption with Keyword Search over encrypted cloud data

With the rapid development of cloud computing technology, cloud storage services are becoming more and more mature. However, the storage of sensitive data on remote servers poses privacy risks and is presently a source of concern. Searchable Encryption (SE) is an effective method for protecting sensitive data while preserving server-side searchability. Hierarchical Public key Encryption with Keyword Search (HPEKS), a new variant of SE, allows users with higher access permission to search over encrypted data sent to lower-level users. To the best of our knowledge, there exist only four HPEKS schemes in the literature. Two of them are in traditional public-key setting, and the remaining ones are identity-based public key cryptosystems. Unfortunately, all of the four existing HPEKS schemes are vulnerable against inside Keyword Guessing Attacks (KGAs). Moreover, all of the existing HPEKS schemes are based on the computationally expensive bilinear pairing operation which dramatically increases the computational costs. To overcome these issues, in this paper, we introduce the notion of Hierarchical Identity-Based Authenticated Encryption with Keyword Search (HIBAEKS). We formulate a security model for HIBAEKS and propose an efficient pairing-free HIBAEKS scheme. We then prove that the proposed HIBAEKS scheme is secure under the defined security model and is resistant against KGAs. Finally, we compare our proposed scheme with related constructions regarding security requirements, computational and communication costs to indicate the overall superiority of our proposed scheme.

Pairing-free certificateless blind signature scheme for smart grid

The smart grid is an emerging power system that can realize the information exchange between users and power companies in two-way communication and adjust power companies’ power supply according to the real-time power requests from smart meters on the users’ side. However, since malicious attackers can eavesdrop on two-way communication to collect and transmit information, they may leak users’ information. Therefore, this paper proposes a new certificateless blind signature (CLBS) scheme with batch verification function and improves a power request system model for the smart grid to protect users’ privacy. In addition, the proposed CLBS scheme simplifies the certificate management process in the traditional public key cryptosystem and eliminates the hidden key escrow in the identity-based public key cryptosystem. The unforgeability of the scheme is proved through the random oracle model, and the scheme’s security can be reduced to the intractability of the elliptic curve discrete logarithm problem (ECDLP). The analysis results show that our scheme does not use the time-consuming bilinear pairing operation, and has obvious advantages in computing performance compared with the existing signature schemes.

Construction of Certificateless Proxy Signcryption Scheme From CMGs

As a cryptography primitive for secure data transmission, certificateless proxy signcryption (CLPS) allows an original signcrypter to entrust his signing authority to a proxy signcrypter for signing specified message on his behalf. In this paper, we combine CLPS with cyclic multiplication groups (CMGs) to construct a new certificateless proxy signcryption scheme from CMGs (CMGs-CLPSS). CMGs-CLPSS will receive significant attention because it simplifies the traditional public key cryptosystem (PKC) and solves the key escrow issue suffered by identity-based public key cryptosystem (IB-PKC). In CMGs-CLPSS, an encrypted message can only be decrypted by a designated receiver who is also responsible for verifying the message; moreover, if a later dispute over repudiation occurs, the designated receiver can readily announce ordinary CLPS for public verification without any extra computation effort. CMGs-CLPSS is proved to have the indistinguishability under adaptive chosen-ciphertext attacks (IND-CCA2 security) and existential unforgeability under adaptive chosen-message attacks (UF-CMA security) in the random oracle model. CMGs-CLPSS outperforms the existing schemes on the basis of computational complexity and is suitable for applications in digital contract signing and online proxy auction, and so on.

Certificateless and identity-based authenticated asymmetric group key agreement

Group key agreement (GKA) is one of the traditional ways to guarantee the subsequent secure group communications. However, conventional GKA protocols face two limitations, i.e., they require two or more rounds to establish secure channels and are sender restricted. Asymmetric group key agreement (AGKA) eliminates above two limitations of GKA. It allows a group of users to establish a public group encryption key and a different secret decryption key of each group member in one round. Any user who knows the group encryption key can encrypt to the group members. This paper studies authenticated AGKA in certificateless and identity-based public key cryptosystems. We formalize the security model of certificateless authenticated asymmetric group key agreement and realize a one-round certificateless authenticated asymmetric group key agreement protocol to resist active attacks in the real world. We also investigate the relation between certificateless authenticated AGKA and identity-based authenticated AGKA. We propose a concrete conversion from certificateless authenticated AGKA to session key escrow-free identity-based authenticated AGKA.

A brief review of revocable ID-based public key cryptosystem

Summary The design of ID-based cryptography has received much attention from researchers. However, how to revoke the misbehaviour/compromised user in ID-based public key cryptosystem becomes an important research issue. Recently, Tseng and Tsai proposed a novel public key cryptosystem called revocable ID-based public key cryptosystem (RIBE) to solve the revocation problem. Later on, numerous research papers based on the Tseng-Tsai key RIBE were proposed. In this paper, we brief review Tseng and Tsai's RIBE. We hope this review can help the readers to understand the Tseng and Tsai's revocable ID-based public key cryptosystem.

NaEPASC: a novel and efficient public auditing scheme for cloud data

Cloud computing is deemed the next-generation information technology (IT) platform, in which a data center is crucial for providing a large amount of computing and storage resources for various service applications with high quality guaranteed. However, cloud users no longer possess their data in a local data storage infrastructure, which would result in auditing for the integrity of outsourced data being a challenging problem, especially for users with constrained computing resources. Therefore, how to help the users complete the verification of the integrity of the outsourced data has become a key issue. Public verification is a critical technique to solve this problem, from which the users can resort to a third-party auditor (TPA) to check the integrity of outsourced data. Moreover, an identity-based (ID-based) public key cryptosystem would be an efficient key management scheme for certificate-based public key setting. In this paper, we combine ID-based aggregate signature and public verification to construct the protocol of provable data integrity. With the proposed mechanism, the TPA not only verifies the integrity of outsourced data on behalf of cloud users, but also alleviates the burden of checking tasks with the help of users’ identity. Compared to previous research, the proposed scheme greatly reduces the time of auditing a single task on the TPA side. Security analysis and performance evaluation results show the high efficiency and security of the proposed scheme.

An identity-based strongly unforgeable signature without random oracles from bilinear pairings

This paper proposes an identity-based (ID-based) signature (IBS) scheme which is strongly unforgeable in the standard model whose security is reduced to the hardness of the computational Diffie-Hellman (CDH) problem in bilinear groups. Currently, the ID-based encryption scheme (IBE) due to Waters is known to be the most practically efficient IBE whose security is guaranteed in the standard model depending on the decisional bilinear Diffie-Hellman (BDH) assumption. While as a solution for an ID-based signature of a total ID-based public key cryptosystem cooperating with Waters IBE, we share Waters’s construction and system parameters to keep a key pair corresponding to each identity unchanged, our IBS needs only one group element for signing of messages and two elements for its randomness as supplementary parameters plus the original system parameters. Accordingly, thanks to requiring about half the system parameters against previous ID-based signatures proved secure without using random oracles under the standard complexity assumptions like CDH or BDH, our IBS is the more suitable for storage and communication requirements. In particular, this covers a stronger security property called strong unforgeability in the standard model in itself without applying any transformation technique.

A new construction of identity-based group signature

Identity-based (simply ID-based) public key cryptosystem allows the user to use his identity as the public key, which can be a good alternative for certificate-based public key setting. Group signature allows any member of a group to sign on behalf of the group without revealing his identity. A complete ID-based group signature scheme was proposed in ACISP’06. However, it was very impractical. In this paper, we give a construction of identity-based group signatures. Then, we construct an efficient ID-based group signature scheme. We also show that the group signature scheme is provably secure in the random oracle model.

New blind signature scheme without trusted private key generator

In order to eliminate the inherent key escrow problem in identity-based public key cryptosystem,a new identity-based blind signature scheme without trusted Private Key Generator(PKG) was proposed.Under the random oracle model,the scheme was proved to be existentially unforgeable against adaptive chosen message and identity attacks from common attackers or semi-honest PKG,and the security was reduced to computational Diffie-Hellman assumption.For the forgery attacks from the malicious PKG,the legitimate signer can prove to the arbitration institution that the signature is forged by trace algorithm.

Security Vulnerability in Identity-Based Public Key Cryptosystems from Pairings

 Abstract—Many identity-based public key cryptosystems from bilinear pairings use hash functions to construct their public keys. Most of these schemes only specify the need of applying cryptographic strong or collision free hash functions, without giving any detail of which or what hash functions should be used. Traditional understanding of a cryptographic strong hash function has three security properties, which are pre-image resistance, second pre-image resistance and collision resistance. However, with only these three properties, in this paper we show a potential security vulnerability of identity-based cryptographic cryptosystems if the hash functions used are not correctly constructed. To fix this vulnerability, this paper defines an additional desirable security property for the hash functions in these identity-based cryptosystems.

Certificateless undeniable signatures from bilinear maps

Certificateless public-key cryptosystem avoids the inherent key escrow problem in identity-based public-key cryptosystem, and does not need expensive certificates in the public key infrastructure. This cryptographic primitive has received a significant attention since it was introduced, and lots of certificateless schemes have been proposed in the past years. In this paper, we propose an certificateless undeniable signature scheme based on bilinear maps. To formally analyze the security of the proposed scheme, we extend security notions of undeniable signatures in the traditional public key infrastructure to the certificateless setting. Under the formally defined security models, we prove that our proposed scheme satisfies all the security properties under certain standard assumptions in the random oracle model. Compared with existed certificateless undeniable signatures, the sign algorithm of our scheme is more efficient, the weakness is that the unforgeability of our scheme is proved in a weak model.

An Identity (ID)-Based Threshold Multi-Secret Sharing Scheme

为了避免现有秘密共享方案中的秘密份额分发机制的不足,结合基于身份(ID)的公钥密码技术,提出了利用参与者私钥作为其主份额的秘密份额分发方法.首先,对Zheng提出的签密方案进行了安全分析,发现其不具备前向保密性,并针对该安全问题,提出了一个改进的签密方案.同时,在所提出的改进方案的基础上,结合基于ID的公钥密码系统,提出了一个新的门限多重秘密共享方案.该方案有效地解决了秘密份额的安全分发问题,不需要秘密分发者和参与者之间事先进行任何信息交互,能够在分发秘密的同时分发秘密份额.该方案还具有前向保密性,即使秘密分发者的私钥被泄漏,也不会影响之前所共享秘密的安全性.因此,所提出的基于身份的秘密共享方案具有更高的安全性和有效性,能够更好地满足应用需求.;In order to avoid the flaw of the secret shadow distribution method in the existing secret sharing schemes, a secret shadow distribution method is proposed with the ID-based public key technology integrated, which uses the participant's private key as his master shadow. Firstly, security analyses are made on Zheng's signcryption scheme, which shows his scheme does not offer forward secrecy. Then, an improvement is made on Zheng's signcryption scheme and a new scheme is proposed. Based on the proposed signcryption scheme and the ID-based public key cryptosystem, a new threshold multi-secret sharing scheme is proposed. The problem of the secret shadow distribution is well resolved, and no information exchange is needed between the secret dealer and each participant in advance. The secret shadow distribution can be processed during the secret distribution. At the same time, the proposed scheme offers forward secrecy. That is to say, even if the private key of the secret dealer is exposed, the security of the shared secrets will not be threatened. Therefore, the proposed ID-based secret sharing scheme is more secure and effective than others, and it can be more applicable.

ID-based cryptography using symmetric primitives

A general method for deriving an identity-based public key cryptosystem from a one-way function is described. We construct both ID-based signature schemes and ID-based encryption schemes. We use a ...

A new ID-based proxy multi-signature scheme from bilinear pairings

ID-based public key cryptosystem can be a good alternative for certificate-based public key setting. This paper provides an efficient ID-based proxy multi-signature scheme from pairings. In the random oracle model, we prove that our new scheme is secure against existential delegation forgery with the assumption that Hess's scheme-1 is existential unforgeable, and that our new scheme is secure against existential proxy multi-signature forgery under the hardness assumption of the computational Diffie-Hellman problem.

ID based public key cryptosystems based on Okamoto and Tanaka's ID based one way communication scheme

With a slight modification to Okamoto and Tanaka's ID-based one-way communication scheme, two identity-based public-key cryptosystems are proposed. These systems do not possess the conspiracy problem and can withstand certain key attacks common to most public-key cryptosystems.