Key escrow

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

Towards Large-Scale and Privacy-Preserving Contact Tracing in COVID-19 Pandemic: A Blockchain Perspective

Abstract: Activity-tracking applications and location-based services using short-range communication (SRC) techniques have been abruptly demanded in the COVID-19 pandemic, especially for automated contact tracing. The attention from both public and policy keeps raising on related practical problems, including 1) how to protect data security and location privacy? 2) how to efficiently and dynamically deploy SRC Internet of Thing (IoT) witnesses to monitor large areas? To answer these questions, in this paper, we propose a decentralized and permissionless blockchain protocol, named Bychain . Specifically, 1) a privacy-preserving SRC protocol for activity-tracking and corresponding generalized block structure is developed, by connecting an interactive zero-knowledge proof protocol and the key escrow mechanism. As a result, connections between personal identity and the ownership of on-chain location information are decoupled. Meanwhile, the owner of the on-chain location data can still claim its ownership without revealing the private key to anyone else. 2) An artificial potential field-based incentive allocation mechanism is proposed to incentivize IoT witnesses to pursue the maximum monitoring coverage deployment. We implemented and evaluated the proposed blockchain protocol in the real-world using the Bluetooth 5.0. The storage, CPU utilization, power consumption, time delay, and security of each procedure and performance of activities are analyzed. The experiment and security analysis is shown to provide a real-world performance evaluation.

Proxy Signature Scheme with Effective Revocation Using Bilinear Pairings

Abstract: We present a proxy signature scheme using bilinear pairings that provides effective proxy revocation. The scheme uses a binding-blinding technique to avoid secure channel requirements in the key issuance stage. With this technique, the signer receives a partial private key from a trusted authority and unblinds it to get his private key, in turn, overcomes the key escrow problem which is a constraint in most of the pairing-based proxy signature schemes. The scheme fulfills the necessary security requirements of proxy signature and resists other possible threats.

New ID-based group signature from pairings

Abstract: We argue that traditional identity-based systems from pairings seem unsuitable for designing group signature schemes due to the problem of key escrow. In this paper we first propose new ID-based public key systems without trusted PKG (Private Key Generator) from bilinear pairings. In our new ID-based systems, if the dishonest PKG impersonates an honest user to communicate with others, the user can provide a proof of treachery of the PKG afterwards, which is similar to certificate-based systems. Therefore, our systems reach the Girault’s trusted level 3. We then propose a group signature scheme under the new ID-based systems, the security and performance of which rely on the new systems. The size of the group public key and the length of the signature are independent on the numbers of the group.

Identity-based security systems for vehicular ad-hoc networks

Abstract: Cooperative Intelligent Transport Systems (ITS) based on vehicular car to car ad-hoc networks have been extensively investigated by the research community and industry to improve efficiency and safety in road traffic. The management and control of the vehicular ad-hoc network (VANET) is still one of the most challenging research fields in the networking domain. In particular, security and privacy protection are very important requirements for the design of VANETs. The potential high dynamicity of VANETs and the need for flexibility and scalability in ITS applications supports the research for new security frameworks and the application of novel cryptographic schemes that ensure authentication, integrity and confidentiality given the constrained computational environment in which such applications usually operate. This paper investigates the application of identity based (id-based, for short) cryptographic (IBC) scheme (in particular, signature schemes) to provide better security and privacy for VANET. Along with a presentation of the state-of-the-art in this area, this paper presents a security framework for car-to-car VANETs based on a protocol for the distributed generation of signing keys that overcome key escrow issues.

Key Management Using Certificateless Public Key Cryptography in Ad Hoc Networks

Abstract: As various applications of wireless ad hoc network have been proposed, security has become one of the big research challenges and is receiving increasing attention. In this paper, we propose a distributed key management approach by using the recently developed concepts of certificateless public key cryptography and threshold secret sharing schemes. Without any assumption of prefixed trust relationship between nodes, the ad hoc network works in a self-organizing way to provide the key generation and key management services using threshold secret sharing schemes, which effectively solves the problem of single point of failure. Certificateless public key cryptography is applied here not only to eliminate the need for certificates, but also to retain the desirable properties of identity-based key management approaches without the inherent key escrow problem.