다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

In this paper, we define and explore proofs of retrievability (PORs). A POR scheme enables an archive or back-up service (prover) to produce a concise proof that a user (verifier) can retrieve a target file F, that is, that the archive retains and reliably transmits file data sufficient for the user to recover F in its entirety.A POR may be viewed as a kind of cryptographic proof of knowledge (POK), but one specially designed to handle a large file (or bitstring) F. We explore POR protocols here in which the communication costs, number of memory accesses for the prover, and storage requirements of the user (verifier) are small parameters essentially independent of the length of F. In addition to proposing new, practical POR constructions, we explore implementation considerations and optimizations that bear on previously explored, related schemes.In a POR, unlike a POK, neither the prover nor the verifier need actually have knowledge of F. PORs give rise to a new and unusual security definition whose formulation is another contribution of our work.We view PORs as an important tool for semi-trusted online archives. Existing cryptographic techniques help users ensure the privacy and integrity of files they retrieve. It is also natural, however, for users to want to verify that archives do not delete or modify files prior to retrieval. The goal of a POR is to accomplish these checks without users having to download the files themselves. A POR can also provide quality-of-service guarantees, i.e., show that a file is retrievable within a certain time bound.

PORs: Proofs of Retrievability for Large Files

The Internet of Things (IoT) now permeates our daily lives, providing important measurement and collection tools to inform our every decision. Millions of sensors and devices are continuously producing data and exchanging important messages via complex networks supporting machine-to-machine communications and monitoring and controlling critical smart-world infrastructures. As a strategy to mitigate the escalation in resource congestion, edge computing has emerged as a new paradigm to solve IoT and localized computing needs. Compared with the well-known cloud computing, edge computing will migrate data computation or storage to the network “edge,” near the end users. Thus, a number of computation nodes distributed across the network can offload the computational stress away from the centralized data center, and can significantly reduce the latency in message exchange. In addition, the distributed structure can balance network traffic and avoid the traffic peaks in IoT networks, reducing the transmission latency between edge/cloudlet servers and end users, as well as reducing response times for real-time IoT applications in comparison with traditional cloud services. Furthermore, by transferring computation and communication overhead from nodes with limited battery supply to nodes with significant power resources, the system can extend the lifetime of the individual nodes. In this paper, we conduct a comprehensive survey, analyzing how edge computing improves the performance of IoT networks. We categorize edge computing into different groups based on architecture, and study their performance by comparing network latency, bandwidth occupation, energy consumption, and overhead. In addition, we consider security issues in edge computing, evaluating the availability, integrity, and the confidentiality of security strategies of each group, and propose a framework for security evaluation of IoT networks with edge computing. Finally, we compare the performance of various IoT applications (smart city, smart grid, smart transportation, and so on) in edge computing and traditional cloud computing architectures.

A Survey on the Edge Computing for the Internet of Things

All one needs to know about fog computing and related edge computing paradigms: A complete survey

Edge computing: A survey

Existing security and identity-based vehicular communication protocols used in Vehicular Ad-hoc Networks (VANETs) to achieve conditional privacy-preserving mostly rely on an ideal hardware device called tamper-proof device (TPD) equipped in vehicles. Achieving fast authentication during the message verification process is usually challenging in such strategies and further they suffer performance constraints from resulting overheads. To address such challenges, this paper proposes a novel Chinese remainder theorem (CRT)-based conditional privacy-preserving authentication scheme for securing vehicular authentication. The proposed protocol only requires realistic TPDs, and eliminates the need for pre-loading the master key onto the vehicle's TPDs. Chinese remainder theorem can dynamically assist the trusted authorities (TAs) whilst generating and broadcasting new group keys to the vehicles in the network. The proposed scheme solves the leakage problem during side channel attacks, and ensures higher level of security for the entire system. In addition, the proposed scheme avoids using the bilinear pairing operation and map-to-point hash operation during the authentication process, which helps achieving faster verification even under increasing number of signature. Moreover, the security analysis shows that our proposed scheme is secure under the random oracle model and the performance analysis shows that our proposed scheme is efficient in reducing computation and communication overheads.

/pdf/pa-crt-chinese-remainder-theorem-based-conditional-privacy-22bo0wqhit.pdf

PA-CRT: Chinese Remainder Theorem Based Conditional Privacy-Preserving Authentication Scheme in Vehicular Ad-Hoc Networks

Vehicular ad-hoc networks (VANETs) have been emerging based on the state-of-art technologies in wireless and network communications. The message authentications between vehicles and roadside units are essential for the security of VANETs. Messages should be signed and verified before they could be trusted. The real identity of vehicles should not be revealed, but which is only traceable by authorized parties. Existing solutions either rely heavily on a tamper-proof hardware device or cannot satisfy the security requirement. Communication overhead as another issue has also not been well addressed in previously reported studies. To address these issues, in this paper, we propose the SPACF scheme that is based on software without relying on any special hardware. We use the Cuckoo filter and the binary search methods to achieve higher success rate than the previous schemes in the batch verification phase. In order to guarantee that it can satisfy message authentication requirement, existential unforgeability of underlying signature against adaptively chosen-message attack is proved under the elliptic curve discrete logarithm problem in the random oracle model. The evaluation results show that our proposed scheme is more efficient than the previous schemes since it is pairing free and does not use map-to-point hash functions, and it satisfies security and privacy requirements of vehicular ad hoc networks.

SPACF: A Secure Privacy-Preserving Authentication Scheme for VANET With Cuckoo Filter

With the progress in wireless communication technology and the increasing number of vehicles, vehicular ad hoc networks (VANETs) have become essential for improving road conditions and enhancing driving experience. The core of the VANETs is the communication between different vehicles, and the security of the communication is based on message authentication. Several schemes have been designed to enhance the efficiency of message authentication. However, these schemes have the disadvantage of redundant authentication, i.e., repeated authentication of the same message, and fail to seek invalid messages from the batch of messages. To solve these problems, this paper introduces a novel edge-computing concept into the message-authentication process of VANETs. In our scheme, the roadside unit can efficiently authenticate messages from nearby vehicles and broadcast the authentication results to the vehicles within its communication range, thereby reducing redundant authentication and enhancing the efficiency of the entire system. The security analysis results show that the proposed scheme satisfies the security requirements of the VANETs. The performance analysis results show that the proposed scheme can not only work well in an ideal environment where the attacker is absent but also capable of quickly identifying valid and invalid messages even if the VANET is attacked.

An Efficient Message-Authentication Scheme Based on Edge Computing for Vehicular Ad Hoc Networks

Quantum key agreement protocol is a key establishment technique whereby a classical shared secret key is derived by two or more specified parties equally and fairly based on quantum mechanics principles. In this paper, we presented two novel quantum key agreement protocols for two parties and more parties based on entanglement swapping. The proposed protocols utilize Bell states as the quantum resources, and further perform Bell measurements as the main operations. In addition, they don't require the help of a trusted center or third party, but could ensure fairness, security and efficiency.

Multi-party quantum key agreement with bell states and bell measurements

With the advancements in social media and rising demand for real traffic information, the data shared in vehicular ad hoc networks (VANETs) indicate that the size and amount of requested data will continue increasing. Vehicles in the same area often have similar data downloading requests. If we ignore the common requests, the resource allocation efficiency of the VANET system will be quite low. Motivated by this fact, we propose an efficient and privacy-preserving data downloading scheme for VANETs, based on the edge computing concept. In the proposed scheme, a roadside unit (RSU) can find the popular data by analyzing the encrypted requests sent from nearby vehicles without having to sacrifice the privacy of their download requests. Further, the RSU caches the popular data in nearby qualified vehicles called edge computing vehicles (ECVs). If a vehicle wishes to download the popular data, it can download it directly from the nearby ECVs. This method increases the downloading efficiency of the system. The security analysis results show that the proposed scheme can resist multiple security attacks. The performance analysis results demonstrate that our scheme has reasonable computation and communication overhead. Finally, the OMNeT++ simulation results indicate that our scheme has good network performance.

Hong Zhong

Papers

PA-CRT: Chinese Remainder Theorem Based Conditional Privacy-Preserving Authentication Scheme in Vehicular Ad-Hoc Networks

SPACF: A Secure Privacy-Preserving Authentication Scheme for VANET With Cuckoo Filter

An Efficient Message-Authentication Scheme Based on Edge Computing for Vehicular Ad Hoc Networks

Multi-party quantum key agreement with bell states and bell measurements

Edge Computing in VANETs-An Efficient and Privacy-Preserving Cooperative Downloading Scheme