Key escrow

About: Key escrow is a research topic. Over the lifetime, 1162 publications have been published within this topic receiving 19616 citations.

Enhancing Data Security and Access Control in Cloud Environment using Modified Attribute Based Encryption Mechanism

Abstract: Social networking and growing popularity of cloud services have made everyone to communicate each other in an easiest way. File sharing and distribution are the frequently used services provided by cloud service providers, although these facilities reduce cost of data sharing but at the same time data security and access control is the major problem. Many renowned service providers have faced the challenges to secure data and provide better access control, and we know once the data is leaked we cannot recover the data loss. Thus in order to ensure better security we need for focus on the two major problems, and those are access control and encryption policy. Cipher text policy attribute based encryption is the most effective solution for access control in real time scenarios where owner can actually decide the access rights for the end-user, but it comes with key escrow problem. We are proposing our modified escrow-free key issuing protocol to solve the problem of key escrow and our Modified Attribute Based Encryption scheme to achieve all security requirements to get a robust and secure system. Further we evaluate our model on the basis of results and lastly we conclude the paper.

An Escrow-Free Hierarchical Identity-Based Signature Scheme from Composite Order Bilinear Groups

Abstract: Hierarchical Identity-Based Signature (HIBS) is an efficient digital signature scheme to be applied to the cloud storage. However, the key escrow problem, which is an inherent problem in HIBS scheme, primarily hinders the widespread adoption of this cryptosystem in practice. In this paper we propose an HIBS scheme using composite order bilinear groups, and present the methodology of dual system signature to prove that our scheme is secure against existential forgery on adaptively chosen message and identity attack under standard model. Based on the scheme, we propose an escrow-free method that employs user-selected-secret signing algorithm and obtain an escrow-free HIBS scheme. We illuminate that our scheme can resist the key abusing and user slandering attacks.

An Efficient Pairing-Free Certificateless Authenticated Two-Party Key Agreement Protocol Over Elliptic Curves

Abstract: Due to the high computation cost of bilinear pairings, pairing-free cryptosystems have received widespread attention recently. Various pairing-free two-party key agreement protocols in the context of public key cryptography (PKC) have been studied. To avoid complex certificate management in traditional PKC and key escrow problem in identity-based ones, several certificateless cryptosystems have been proposed in this research area. In this paper, we proposed a secure and efficient certificateless pairing-free two-party key agreement protocol. In comparison with related works, our protocol requires less computational cost.

Security analysis of two certificateless short signature schemes

Abstract: Certificateless public key cryptography (CL-PKC) combines the advantage of both traditional PKC and identity-based cryptography (IBC) as it eliminates the certificate management problem in traditional PKC and resolves the key escrow problem in IBC. Recently, Choi et al. and Tso et al. proposed two different efficient CL short signature schemes and claimed that the two schemes are secure against super adversaries and satisfy the strongest security. In this study, the authors show that both Choi et al. 's scheme and Tso et al. 's scheme are insecure against the strong adversaries who can replace users' public keys and have access to the signing oracle under the replaced public keys.

A Secure and Efficient Privacy-Preserving Authentication Scheme for Vehicular Networks with Batch Verification Using Cuckoo Filter

Abstract: The wireless nature of vehicular networks causes serious security and privacy issues that need to be addressed. To satisfy the security and privacy requirements in vehicular networks, a number of certificateless signature based authentication schemes have been proposed as it not only avoid certificate management issue in PKI-based solutions but also solves the key escrow problem in solutions that depends on ID-based signatures. However, many schemes are inefficient due to the use of computationally intensive bilinear pairing operation and map-to-point hash function. To further improve efficiency, schemes supporting batch verification is highly desirable. In this paper, based on a pairing-free online/offline certificateless signature scheme, we propose a secure and efficient privacy-preserving authentication scheme for vehicular networks by specifically improving the batch verification efficiency using cuckoo filter. The signature scheme does not use the expensive pairing operations or map-to-point hash functions, thus has a higher computation efficiency. More importantly, by using the cuckoo filters, the roadside units can generate a notification message for vehicles about the validity of the signatures in the batch verification to assist the message authentication of vehicles. Moreover, the binary search method is used in the batch verification process to avoid dropping the whole batch in case an invalid signature exists. Our proposed scheme is secure, efficient and it satisfies all the security and privacy requirements of vehicular networks.