Nowadays, blockchain has become one of the most cutting-edge technologies, which has been widely concerned and researched. However, the quantum computing attack seriously threatens the security of blockchain, and related research is still less. Targeting at this issue, in this paper, we present the definition of post-quantum blockchain (PQB) and propose a secure cryptocurrency scheme based on PQB, which can resist quantum computing attacks. First, we propose a signature scheme based on lattice problem. We use lattice basis delegation algorithm to generate secret keys with selecting a random value, and sign message by preimage sampling algorithm. In addition, we design the first-signature and last-signature in our scheme, which are defined as double-signature. It is used to reduce the correlation between the message and the signature. Second, by combining the proposed signature scheme with blockchain, we construct the PQB and propose this cryptocurrency scheme. Its security can be reduced to the lattice short integer solution (SIS) problem. At last, through our analysis, the proposed cryptocurrency scheme is able to resist the quantum computing attack and its signature satisfies correctness and one-more unforgeability under the lattice SIS assumption. Furthermore, compared with previous signature schemes, the sizes of signature and secret keys are relatively shorter than that of others, which can decrease the computational complexity. These make our cryptocurrency scheme more secure and efficient.
Christian Esposito, Alfredo De Santis, Genny Tortora, Henry Chang · 5 authors
One particular trend observed in healthcare is the progressive shift of data and services to the cloud, partly due to convenience (e.g. availability of complete patient medical history in real-time) and savings (e.g. economics of healthcare data management). There are, however, limitations to using conventional cryptographic primitives and access control models to address security and privacy concerns in an increasingly cloud-based environment. In this paper, we study the potential to use the Blockchain technology to protect healthcare data hosted within the cloud. We also describe the practical challenges of such a proposition and further research that is required.
The paradigm of Internet of Things (IoT) is paving the way for a world, where many of our daily objects will be interconnected and will interact with their environment in order to collect information and automate certain tasks. Such a vision requires, among other things, seamless authentication, data privacy, security, robustness against attacks, easy deployment, and self-maintenance. Such features can be brought by blockchain, a technology born with a cryptocurrency called Bitcoin. In this paper, a thorough review on how to adapt blockchain to the specific needs of IoT in order to develop Blockchain-based IoT (BIoT) applications is presented. After describing the basics of blockchain, the most relevant BIoT applications are described with the objective of emphasizing how blockchain can impact traditional cloud-centered IoT applications. Then, the current challenges and possible optimizations are detailed regarding many aspects that affect the design, development, and deployment of a BIoT application. Finally, some recommendations are enumerated with the aim of guiding future BIoT researchers and developers on some of the issues that will have to be tackled before deploying the next generation of BIoT applications.
Distributed ledger technologies (DLTs) are receiving much attention. As discussion focuses on the potential applications of DLTs, Blockchain-as-a-Service (BaaS) offerings are emerging to provide the underlying supporting infrastructure. BaaS entails a provider supplying and managing aspects of a DLT infrastructure to facilitate and bring efficiencies regarding the development, experimentation, deployment, and the ongoing management of DLT applications. However, much of the interest in DLTs stems from their potential to decentralise, disintermediate, and enable ‘trustless’ interactions. At first sight, BaaS – being offered by a provider – appears to run counter to this. In practice, whether BaaS raises substantive trust concerns depends on the nature of the offering, the application’s specifics, and the participants’ goals and risk appetite. This paper elaborates the nature of BaaS offerings, exploring the role of the provider as part of a wider infrastructure, and related issues of trust.
Blockchain ledgers and the Cloud are a perfect match. On the one hand, there is an inherent requirement for multiple separate authentication nodes to validate every Blockchain transaction with each node requiring substantial encryption calculation capability. On the other hand, massive economies of scale can bring down the cost per transaction, and provide service continuity. Additionally, the Cloud provides a perfect incubator for proof-of-concept projects. This paper considers the future implications of Blockchain, as the concept of disintermediated trustless ledgers stimulates the imagination of computer scientists and innovators. The Cloud’s role in implementing this new paradigm is also highlighted, as a new decentralized P2P-Cloud model. Finally, this paper discusses how Blockchain may be integrated into the university level computer science and information technology curriculum.
Blockchain and verifiable identities have a lot of potential in future distributed software applications e.g. smart cities, eHealth, autonomous vehicles, networks, etc. In this paper, we proposed a novel technique, namely VeidBlock, to generate verifiable identities by following a reliable authentication process. These entities are managed by using the concepts of blockchain ledger and distributed through an advance mechanism to protect them against tampering. All identities created using VeidBlock approach are verifiable and anonymous therefore it preserves user's privacy in verification and authentication phase. As a proof of concept, we implemented and tested the VeidBlock protocols by integrating it in a SDN based infrastructure. Analysis of the test results yield that all components successfully and autonomously performed initial authentication and locally verified all the identities of connected components.
Recently, cryptocurrencies and bitcoin have become the main topics in the financial industry. A cryptocurrency is a digital or virtual currency that uses cryptography for security. A cryptocurrency is difficult to counterfeit because of this security feature. A defining feature of a cryptocurrency, and arguably its most endearing allure, is its organic nature; it is not issued by any central authority, rendering it theoretically immune to government interference or manipulation. Cryptocurrencies have their benefits and drawbacks. The paper elaborates different aspects of cryptocurrencies, starting with their early development, challenges and risks, opportunities, advantages and disadvantages, and their future. In addition, the paper covered issues related to the practical and technical function of cryptocurrencies. It was concluded that is not easy to predict the future of cryptocurrencies, since there is a lot to be done especially in the field of formal regulations. However, the banks and other financial institutions should see and consider cryptocurrencies as an alternative for the financial transactions in the future. Key words: cryptocurrencies, development, advantages disadvantages, financial transactions
For the sake of protecting users' privacy from the malicious data which is shared by other people and leasing the pressure of the clouds, an approach of verification based on the Blockchain is put forward in our article. By using the Blockchain to record the hash value and other necessary information of data sharing by other people, we can guarantee that the data user received from a third-party source (such as a cloud storage platform) is the original uploaded data indeed. After taking some experiments on the following method. We confirm that it can be easily distinguished whether a data has been modified by malicious people through our Blockchain-based approach. This Blockchain-based approach of verification can effectively help users find out if the data received is the one exactly he wants. In addition, our approach will imply that the data is not the original one and that data cannot be opened or executed.
Blockchain Technology Applications and Security
Cloud Data Security Solutions
Advanced Steganography and Watermarking Techniques
Dec 1, 2017·2017 IEEE International Symposium on Parallel and Distributed Processing with Applications and 2017 IEEE International Conference on Ubiquitous Computing and Communications (ISPA/IUCC)
Lei Zhou, Guojun Wang, Tongshuai Cui, Xiaofei Xing
Untrusted Computing in cloud is the main obstacle to promote cloud computing services, even users get an initial trusted execution environment, the events of dynamic software deployment are easy to cause a risk of compromised system. TTP and ACS are the common strategies to reach an agreement of valid application list and operations, however, extra entity should be added into the origin network and the reliability of system rely on the trust operation of third party.,,,, ,,,, Consider this network computing model, the directly remote controlled security strategy is lacking for terminal users, while the security of user computing applications are controlled by its resources owner like cloud manager which might be not trusted in whole time. In this paper, we address this problem and propose a consortium blockchain based cleanroom security service protocol (CSSP), to track the deployment and usage of the user's software in a secure and tamper-resistant measure, to prevent running of error or illegal software in user computing environment. Unlike the traditional methods, CSSP is a two side protocol: service provider and user computing node, which reduce the redundant safety hazards nodes and its invalidation problem. Consortium Blockchain is an effectively method to reduce the energy consumption and keep the software service protocol between the manager and the user in safety state. The security analysis and evaluation shows that the approach has major potential in trusted network computing system and provide a higher secure level environment for users.
Dec 1, 2017·2017 IEEE International Symposium on Parallel and Distributed Processing with Applications and 2017 IEEE International Conference on Ubiquitous Computing and Communications (ISPA/IUCC)
With the development of ICT industry, the volume of produced data is experiencing tremendous growth, which motivates more demands of storage capacity. Because of the limited storage capacity of users' terminals, more and more applications prefer to upload data to cloud platforms. However, it is well known that security should not be neglected in existing cloud storage architectures. Motivated by the increasing popularity of emerging blockchain technology, we propose a blockchain-based security architecture for distributed cloud storage. Moreover, we customize a genetic algorithm to solve the file block replica placement problem between multiple users and multiple data centers in the distributed cloud storage environment. Numerical experimental results show that the proposed architecture outperforms the traditional cloud storage architectures in terms of security, with acceptable network transmission delay.
Bitcoin's underlying blockchain database is a novel approach to recordkeeping that has the potential to decentralize big data. Bitcoin's success has inspired a multitude of spinoff projects hoping to use blockchain as a distributed database for records-management innovation in other fields. Misconceptions and exaggerations about blockchain and its capabilities are pervasive in the media. Drawing on perspectives from archival science, dependable computing, and secure computing, this paper surveys current applications, research, and critiques of blockchain to provide an objective assessment of its benefits and limitations. Based on the findings of the survey, this paper proposes three criteria that predict success for blockchain-based data management projects, briefly: dependability, security, and trust.
Because of the distributed nature of cloud computing, the data of cloud may be stored and processed across jurisdictional borders. In such case, collecting digital evidence from cloud computing requires multiparty cooperation. However, as far as we known, there is still no available technic approach for improving the trustworthy of the interaction records of all stakeholders in cloud forensics. This work proposed a process provenance, which provides proof of existence and privacy preservation for process records by using technologies of blockchain and cryptography group signature. The process provenance enhances the trustworthy of the chain of custody for cloud forensics.
Siwan Noh, Youngho Park, Chur Sur, Sang Uk Shin · 5 authors
privacy. An exposure of personal medical records causes damage to the finance, etc. Sometimes, it could put patient's life in danger. To achieve secure data sharing between institutions, many studies use cloud storage to store medical records. However, many studies suppose that cloud service providers were trustworthy. These systems required a key establishment with the cloud service providers and all the access logs are governed by cloud service providers. Patients should ask cloud service providers to check these access logs. However, it can be forged by cloud service providers during the request process. In this paper, we propose blockchain based medical records management system for secure data sharing. In order to share securely, we use proxy re-encryption scheme. Also, we use blockchain technology to audit access logs without modification.
Blockchain is an emerging technology for decentralized and transactional data sharing across a large network of untrusted participants. It enables new forms of distributed software architectures, where agreement on shared states can be established without trusting a central integration point. As a database and computational platform, blockchain has both advantages and disadvantages compared with conventional techniques. Blockchain may be an appropriate choice for some use cases while conventional technologies will be more appropriate for other use cases. A major difficulty for practitioners to decide whether or not to use blockchain is that limited product data or reliable technology evaluation available to assess the suitability of blockchains. In this paper, we propose an evaluation framework that comprises a list of criteria and a typical process for practitioners to assess the suitability of applying blockchain using these criteria based on the characteristics of the use cases. We then use several existing industrial trails to evaluate the feasibility of our framework.
Summary In a data sharing group, each user can upload, modify, and access group files and a user is required to generate a new signature for the modified file after modification. There is a situation that two or more users modify the same file at almost the same time, which should be avoided as it gives rise to a signature conflict. However, the existing schemes do not take it into consideration. In this paper, we proposed a new mechanism SeShare for data storing based on blockchain to realize signature uniqueness, which solves the problem of generating signatures for the same file meanwhile by different group users. Specifically, we record every signature of a file in a blockchain in chronological order, and only one user is allowed to add new signature at the end of the blockchain when modification conflicts occur. On the other hand, to provide a secure data sharing service, SeShare introduces an efficient public auditing scheme for file integrity verification when a group user leaves the group. We also prove the security of the proposed scheme and evaluate the performance at the end of this paper. Our experimental results demonstrate the efficiency of public auditing for user leaving.
Matteo Campanelli, Rosario Gennaro, Steven Goldfeder, Luca Nizzardo
Zero Knowledge Contingent Payment (ZKCP) protocols allow fair exchange of sold goods and payments over the Bitcoin network. In this paper we point out two main shortcomings of current proposals for ZKCP, and propose ways to address them.
Muhamed Turkanović, Marko Hölbl, Kristjan Košič, Marjan Heričko · 5 authors
Blockchain technology enables the creation of a decentralized environment, where transactions and data are not under the control of any third party organization. Any transaction ever completed is recorded in a public ledger in a verifiable and permanent way. Based on the blockchain technology, we propose a global higher education credit platform, named EduCTX. This platform is based on the concept of the European Credit Transfer and Accumulation System (ECTS). It constitutes a globally trusted, decentralized higher education credit, and grading system that can offer a globally unified viewpoint for students and higher education institutions (HEIs), as well as for other potential stakeholders, such as companies, institutions, and organizations. As a proof of concept, we present a prototype implementation of the environment, based on the open-source Ark Blockchain Platform. Based on a globally distributed peer-to-peer network, EduCTX will process, manage, and control ECTX tokens, which represent credits that students gain for completed courses, such as ECTS. HEIs are the peers of the blockchain network. The platform is a first step toward a more transparent and technologically advanced form of higher education systems. The EduCTX platform represents the basis of the EduCTX initiative, which anticipates that various HEIs would join forces in order to create a globally efficient, simplified, and ubiquitous environment in order to avoid language and administrative barriers. Therefore, we invite and encourage HEIs to join the EduCTX initiative and the EduCTX blockchain network.
In this letter we propose Meta-key, a data-sharing mechanism that enables users share their encrypted data under a blockchain-based decentralized storage architecture. All the data-encryption keys are encrypted by the owner's public key and put onto the blockchain for safe and secure storage and easy key-management. Encrypted data are stored in dedicated storage nodes and proxy re-encryption mechanism is used to ensure secure data-sharing in the untrusted environment. Security analysis of our model shows that the proxy re-encryption adopted in our system is naturally free from collusion-attack due to the specific architecture of Meta-key.
We summarize the results and perspectives from a companion article, where we presented and evaluated an alternative architecture for data storage in distributed networks. We name the bio-inspired architecture RAIN, and it offers file storage service that, in contrast with current centralized cloud storage, has privacy by design, is open source, is more secure, is scalable, is more sustainable, has community ownership, is inexpensive, and is potentially faster, more efficient, and more reliable. We propose that a RAIN-style architecture could form the backbone of the Internet of Things that likely will integrate multiple current and future infrastructures ranging from online services and cryptocurrency to parts of government administration.
The Elliptic Curve Digital Signature Algorithm (ECDSA), de nes a technique for generating and validating digital signatures. We start by reviewing the mathematics behind the Digital Signature Algorithm (DSA) and its elliptic curve analogue (ECDSA). Secondly, we describe how the ECDSA is used in Bitcoin technology.
Blockchain's ever increasing size has become a major problem. Bitcoin [7], for example, has grown to 115120 MB as of May 2017, which is roughly 115 GB. This uncontrollable growth of the Blockchain is bound to become an issue in the future, as hard disks may become too small to store the entire Blockchain history and traversing the transactions databases may become increasingly slow. Already, there are lightweight clients in various Blockchain platforms (Bitcoin included), who do not store the entire chain locally but rely on a third party to send them the blocks they need. There are many issues with these clients, mainly security problems, since they go back to trusting a central authority rather than gaining trust from several distributed peers. These clients' knowledge of the Blockchain is solely based on some third party that should be trusted, while the conceptual base for Blockchain is trust distributing. In this paper we present two Blockchain abbreviation schemes. The first one is based on the Ethereum [8] project and proposes replacing the full Blockchain with a new Genesis block, which summarizes everyone's account balances at a certain point in time. One possible benefit is to use less communication while still storing the prefix of the old Blockchain (or signature of the Blockchain that can validate a version archived by other participants) in a local archive. Here we trade loss of transaction history for efficiency. Our second contribution is a UNIX based architecture using the file system, for implementing Blockchain. We demonstrate a Blockchain abbreviation technique for this architecture too.