Ingolf Gunnar Anton Pernice, Sebastian Henningsen, Roman Proskalovich, Martin Florian · 6 authors
The price volatility of cryptocurrencies is often cited as a major hindrance to their wide-scale adoption. Consequently, during the last two years, multiple so called stablecoins have surfaced---cryptocurrencies focused on maintaining stable exchange rates. In this paper, we systematically explore and analyze the stablecoin landscape. Based on a survey of 24 specific stablecoin projects, we go beyond individual coins for extracting general concepts and approaches. We combine our findings with learnings from classical monetary policy, resulting in a comprehensive taxonomy of cryptocurrency stabilization. We use our taxonomy to highlight the current state of development from different perspectives and show blank spots. For instance, while over 91% of projects promote 1-to-1 stabilization targets to external assets, monetary policy literature suggests that the smoothing of short term volatility is often a more sustainable alternative. Our taxonomy bridges computer science and economics, fostering the transfer of expertise. For example, we find that 38% of the reviewed projects use a combination of exchange rate targeting and specific stabilization techniques that can render them vulnerable to speculative economic attacks - an avoidable design flaw.
Modern malware can take various forms, and has reached a very high level of sophistication in terms of its penetration, persistence, communication and hiding capabilities. The use of cryptography, and of covert communication channels over public and widely used protocols and services, is becoming a norm. In this work, we start by introducing Resource Identifier Generation Algorithms. These are an extension of a well-known mechanism called Domain Generation Algorithms (DGA), which are frequently employed by cybercriminals for bot management and communication. Our extension allows, beyond DNS, the use of other protocols. More concretely, we showcase the exploitation of the InterPlanetary file system (IPFS). This is a solution for the "permanent web", which enjoys a steadily growing community interest and adoption. The IPFS is, in addition, one of the most prominent solutions for blockchain storage. We go beyond the straightforward case of using the IPFS for hosting malicious content, and explore ways in which a botmaster could employ it, to manage her bots, validating our findings experimentally. Finally, we discuss the advantages of our approach for malware authors, its efficacy and highlight its extensibility for other distributed storage services.
A thermally activated absorption heat pump suitable for use in naval expeditionary Environmental Control Units, as well as residential space-conditioning, is developed. Waste heat characteristic of the exhaust stream from a diesel engine GenSet is used to drive an absorption cycle to provide cooling. The heat source is coupled to the heat pump using an intermediate fluid loop for flexible deployment. With minor modifications, the heat pump could also provide heating at high coefficients of performance, resulting in versatile functionality. This technology capitalizes on heat and mass transfer enhancement possible in microscale passages to provide a compact architecture for the components and the overall system. The working fluid pair with zero Global Warming Potential is contained within this assembly, reducing fluid inventories significantly over conventional systems. Quiet, reliable, long-life operation due to the absence of a compressor and the use of few moving parts are further critical distinguishing advantages. Modularity in cooling capacity has been demonstrated through scaling-up of component geometry and internal features and dimensions. The core technology was initially demonstrated with a proof-of-concept microscale absorption chiller measuring 200 × 200 × 34 mm and weighing 7 kg that delivered 300 W of cooling in laboratory tests. In the previous BEETIT project, the team made significant advances over the proof-of-concept. System and component designs with > 10× scale-up in capacity were developed, in a packaged unit capable of standalone operation with a semi-autonomous control system. A cooling capacity of 3.5 kW with a COP > 0.5 at an ambient temperature of 35°C was demonstrated for this natural gas-fired unit. Significant cost reductions in fabrication were achieved using low-cost brazing instead of diffusion bonding. In companion projects funded by the Southern Company and the Georgia Research Alliance, stamping and fluid forming techniques were investigated to fabricate microscale features instead of photochemical etching, thereby leading to significant cost reductions. In a follow-on effort funded by ARPA-E and NAVFAC, a 2.7 kW cooling unit was developed to provide cooling at a severe ambient condition of 51.7°C. The unit was driven directly by diesel engine exhaust heat. Innovative finned heat and mass exchangers for the ambient-coupled condenser and absorber were developed. In the present effort, a standalone, packaged and controllable 10.5 kW cooling capacity absorption chiller is developed. This demonstrates a 30× scale up from the proof-of-concept, thus validating the scalability of microchannel heat exchangers for absorption heat pumps. Autonomous operation algorithms demonstrated enhanced dynamic performance. The knowledge from previous projects was leveraged to develop novel component designs that further helped in miniaturizing the heat exchangers. All coupling fluids are hydronically coupled to aid flexible field deployment. The prototype unit provides design cooling capacity at high ambient temperature conditions of 44°C at COP > 0.6.
Open access
Advanced Thermodynamic Systems and Engines
Refrigeration and Air Conditioning Technologies
Thermodynamic and Exergetic Analyses of Power and Cooling Systems
Cryptocurrencies like Bitcoin may turn upside down not only the system of currencies but that of the international trade.One of the most intriguing questions is how a currency, like Bitcoin, intended to be used globally, can be inserted in the soundly elaborated system of the Vienna Convention on International Sales of Goods (CISG).The paper focuses on the following topics: the nature of Bitcoin, exchange rate fluctuation and hardship, and the determination of late payment interest.
The Kenya Vision 2030 flagship projects expected to generate rapid economic growth in the country are threatened by inadequate source of funding, financial management problems and failure to link policy, planning and expenditure budgeting. The projects continue to experience inadequacies in project appraisal and implementation time overruns. Therefore, without a clear financial framework, fiscal indiscipline, resource misallocation and inefficient use of resources will militate against achieving the Kenya Vision 2030 targets. The overall objective of this study was to evaluate determinants of government expenditure on public flagship projects in Kenya. The specific objectives were to: evaluate the influence of planning process; source of funds; and management responsibility on government expenditure on public flagship projects in Kenya. The theories reviewed in the study were public finance, budget, cost-benefit analysis and principal-agent which provided grounds for conceptual framework. The study employed descriptive research design, positivist philosophy and multiple regression model. The target population was the planned 348 flagship projects for the period 2008-2012. The unit of analysis was projects based on sample size of 96 stratified random sample while data was collected using a questionnaire. The findings showed that planning process, source of funds and management responsibility had significant positive influence in determining government expenditure on public flagship project in Kenya. The study recommended that, public entities should strengthen and improve planning process by deepening MTEF within programme-based budgeting; the National Treasury should increase resources required for financing public flagship projects by considering public-private-partnerships as a potential source; and public entities should improve, strengthen and enforce management responsibility when designing public flagship projects. The two areas suggested for further research were; impact of project characteristics on the choice of Public-Private Partnership financing model; and impact of fiscal decentralization on financing public projects in light of devolved systems of governance in Kenya.
The purpose of the article is to study the forms of state participation in financing of culture in order to solve socio-cultural problems in the context of decentralization. The methodology of the research is characterized by a complex combination of general scientific (formal-logical, method of analysis and synthesis), philosophical (dialectical) and special (comparative, formal-legal) methods, which gave an opportunity to study the experience of other states and Ukraine in the sphere of state participation in financing of culture to overcome socio-cultural problems. The scientific novelty of the work lies in carrying out a comprehensive study of the state's participation in the financing of culture in Ukraine and in the world in order to overcome socio-cultural problems in the context of decentralization reform, and defining the forms of such participation. Conclusions. Ukraine takes direct and indirect participation in financing the culture in order to overcome socio-cultural problems regarding the decline of spirituality and prevention of a humanitarian catastrophe. The main forms of state participation in financing the culture include direct budget financing (at the expense of state and local budgets). Indirect participation provides certain special rights for more efficient use of own funds by budgetary institutions – cultural institutions.
A zero-knowledge proof is a fundamental cryptographic primitive that enables the verification of statements without revealing unnecessary information. Zero-knowledge proofs are a key component of many cryptographic protocols and, often, one of their main efficiency bottlenecks. In recent years there have been great advances in improving the efficiency of zero-knowledge proofs, bring them closer to wide deployability. In this thesis we make another step towards the construction of computationally-efficient zero-knowledge proofs. Specifically, we construct efficient zero-knowledge proofs for the satisfiability of arithmetic circuits for which the computational cost of the prover is only a constant factor more expensive than direct evaluation of the circuit. We also construct efficient zero-knowledge proofs to check the correct execution of (Tiny)RAM programs. In this case the computational cost for the prover is a superconstant factor larger than executing the program directly. Our proofs also support efficient verification and small proof sizes. For security, they rely on symmetric primitives and could potentially withstand attacks from quantum computers. On a different research direction, we look at group signatures, a fundamental primitive which relies on zero-knowledge proofs. A group signature enables users to sign anonymously on behalf of a group of users. In case of dispute a Manager can identify the author of a signature and potentially banish the user from the group. In this thesis we address the fundamental question of defining the security of fully dynamic group signatures, for which the users can join and leave at any time. Differently from other restricted settings, this case has been largely overlooked in the past. Our security model is general, does not implicitly assume existing design paradigms and captures the security of existing models for more restricted settings.
Electronic voting (e-voting) is an electronic means for casting and counting votes. It is an efficient and cost-effective way for conducting a voting procedure, which has characteristic of being magnanimous data and real time and requesting high safety. However, concerns on security of networking and privacy of communication for e-voting have been grown. Securing e-voting is very urgent and has becoming a popular topic in the area of communications and networking. We present techniques to exploit blockchain in P2P network to improve the security of e-voting. First, we design a synchronized model of voting records based on distributed ledger technology (DLT) to avoid forgery of votes. Second, we design a user credential model based on elliptic curve cryptography (ECC) to provide authentication and non-repudiation. Third, we design a withdrawal model that allows voters to change their vote before a preset deadline. By integrating the above designs, a blockchain-based e-voting scheme in P2P network is proposed for essential requirements of e-voting process. To prove and verify the scheme, a blockchain-based e-voting system for multiple candidates has been designed on Linux platforms in P2P network. The system involves electronic voting theory, cryptography, and software engineering theory. The implementation result shows that it is a practical and secure e-voting system, which solves the problem on forgery of votes during e-voting. The blockchain-based e-voting system can be applied to a variety of networking applications directly.
Open access
Internet Traffic Analysis and Secure E-voting
Advanced Steganography and Watermarking Techniques
Jim Kyung-Soo Liew, Richard Li, Tamás Budavári, Avinash Sharma
In this work we examine the largest 100 cryptocurrency return series ranging from 2015 to early 2018. We concentrate our analysis on daily returns and find several interesting stylized facts. First, principal components analysis reveals a complex return generating process. As we examine our data in the most recent year, we find that surprisingly more than one principal component appears to explain the cross-sectional variation in returns. Second, similar to hedge fund returns, cryptocurrency returns suffer from the “beta-in-the-tails” hidden risk. Third, we find that predicting cryptocurrency movements with machine learning and artificial intelligence algorithms is marginally attractive with variation in predictability power per cryptocurrency. Fourth, lower volatile cryptocurrencies are slightly more predictable than more volatile ones. Fifth, evidence exists that efficacy of distinct information sets varies across machine learning algorithms, showing that predictability may be much more complex given a set of machine learning algorithms. Finally, short-term predictability is very tenuous, which suggests that near-term cryptocurrency markets are semi-strong form efficient and therefore, day trading cryptocurrencies may be very challenging. Keywords: cryptocurrency, blockchain, machine learning, bitcoin, beta-in-the-tails, risks
Oliver Stengele, Andreas Baumeister, Pascal Birnstill, Hannes Hartenstein
The integrity of executable binaries is essential to the security of any device that runs them. At best, a manipulated binary can leave the system in question open to attack, and at worst, it can compromise the entire system by itself. In recent years, supply-chain attacks have demonstrated that binaries can even be compromised unbeknownst to their creators. This, in turn, leads to the dissemination of supposedly valid binaries that need to be revoked later.
Georgia Avarikioti, Eleftherios Kokoris Kogias, Roger Wattenhofer, Dionysis Zindros
Off-chain protocols (channels) are a promising solution to the scalability and privacy challenges of blockchain payments. Current proposals, however, require synchrony assumptions to preserve the safety of a channel, leaking to an adversary the exact amount of time needed to control the network for a successful attack. In this paper, we introduce Brick, the first payment channel that remains secure under network asynchrony and concurrently provides correct incentives. The core idea is to incorporate the conflict resolution process within the channel by introducing a rational committee of external parties, called Wardens. Hence, if a party wants to close a channel unilaterally, it can only get the committee's approval for the last valid state. Brick provides sub-second latency because it does not employ heavy-weight consensus. Instead, Brick uses consistent broadcast to announce updates and close the channel, a light-weight abstraction that is powerful enough to preserve safety and liveness to any rational parties. Furthermore, we consider permissioned blockchains, where the additional property of auditability might be desired for regulatory purposes. We introduce Brick+, an off-chain construction that provides auditability on top of Brick without conflicting with its privacy guarantees. We formally define the properties our payment channel construction should fulfill, and prove that both Brick and Brick+ satisfy them. We also design incentives for Brick such that honest and rational behavior aligns. Finally, we provide a reference implementation of the smart contracts in Solidity.
In this work we consider the interplay between multiprover interactive proofs, quantum entanglement, and zero knowledge proofs - notions that are central pillars of complexity theory, quantum information and cryptography. In particular, we study the relationship between the complexity class MIP*, the set of languages decidable by multiprover interactive proofs with quantumly entangled provers, and the class PZK-MIP*, which is the set of languages decidable by MIP* protocols that furthermore possess the perfect zero knowledge property. Our main result is that the two classes are equal, i.e., MIP* = PZK-MIP*. This result provides a quantum analogue of the celebrated result of Ben-Or, Goldwasser, Kilian, and Wigderson (STOC 1988) who show that MIP = PZK-MIP (in other words, all classical multiprover interactive protocols can be made zero knowledge). We prove our result by showing that every MIP* protocol can be efficiently transformed into an equivalent zero knowledge MIP* protocol in a manner that preserves the completeness-soundness gap. Combining our transformation with previous results, we obtain the corollaries that i) all languages that can be solved in non-deterministic double exponential time have zero knowledge MIP* protocols and ii) all co-recursively enumerable languages (which include undecidable problems as well as all decidable problems) have zero knowledge MIP* protocols with vanishing promise gap.
Yixin Li, Bin Cao, Mugen Peng, Long Zhang · 7 authors
Direct Acyclic Graph (DAG)-based ledger and the corresponding consensus algorithm has been identified as a promising technology for Internet of Things (IoT). Compared with Proof-of-Work (PoW) and Proof-of-Stake (PoS) that have been widely used in blockchain, the consensus mechanism designed on DAG structure (simply called as DAG consensus) can overcome some shortcomings such as high resource consumption, high transaction fee, low transaction throughput and long confirmation delay. However, the theoretic analysis on the DAG consensus is an untapped venue to be explored. To this end, based on one of the most typical DAG consensuses, Tangle, we investigate the impact of network load on the performance and security of the DAG-based ledger. Considering unsteady network load, we first propose a Markov chain model to capture the behavior of DAG consensus process under dynamic load conditions. The key performance metrics, i.e., cumulative weight and confirmation delay are analysed based on the proposed model. Then, we leverage a stochastic model to analyse the probability of a successful double-spending attack in different network load regimes. The results can provide an insightful understanding of DAG consensus process, e.g., how the network load affects the confirmation delay and the probability of a successful attack. Meanwhile, we also demonstrate the trade-off between security level and confirmation delay, which can act as a guidance for practical deployment of DAG-based ledgers.
The issues of changing the tax system of the Russian Federation, the system of tax control under the influence of digital technologies have been examined. Electronic government services in the field of taxation, as well as the prospects and directions for the further development and expansion of electronic services used for taxpayers and tax authorities have been considered. The problems of taxation of operations with cryptocurrencies and their tax regulation have been touched upon. Conclusions have been formulated to improve the efficiency of taxation and tax control in the transition to a digital economy.
This article is devoted to the analyses of cryptocurrency investments return. The main purpose of the report is to compare profitability of a cryptocurrency portfolio and an investment portfolio. The report gives the detailed description to the investing. It outlines the essence of cryptocurrency. The report includes the possible definitions of the digital economy. By analyzing the return rates of equity investment and cryptocurrency investment, we define the investing benefits of it.
This article aims to provide a conceptual framework for small and medium-sized enterprises (SMEs) to evaluate the appropriation of blockchain technology for their business needs and challenges. This conceptual framework aims to respond to the problem of increasing speculations surrounding the blockchain that is considered to be an absolute and innovative solution to many business-related problems. However, this argument might not be realistic for SMEs despite this assumption. The main argument of the article is that SMEs should be skeptical while evaluating the appropriation of this technology for their business needs and they should follow a tailored approach whilst adopting it. Otherwise, the likelihood is high that a short-term and unstructured knowledge management process to adopt blockchain will end up with a waste of resources. The present paper conceptualizes an appropriation framework within nine factors namely, reduction of costs, internalization, digital representation of assets, unalterable data recording, network size, transparent and synchronized ledger, scalability, fair trade, and financing. Given the field’s infancy state of development, the paper relies on a qualitative document analysis involving SME literature and extant literature and white papers of blockchain applications.
This paper presents a novel leaderless protocol (FPC-BI: Fast Probabilistic Consensus within Byzantine Infrastructures) with a low communicational complexity and which allows a set of nodes to come to a consensus on a value of a single bit. The paper makes the assumption that part of the nodes are Byzantine, and are thus controlled by an adversary who intends to either delay the consensus, or break it (this defines that at least a couple of honest nodes come to different conclusions). We prove that, nevertheless, the protocol works with high probability when its parameters are suitably chosen. Along this the paper also provides explicit estimates on the probability that the protocol finalizes in the consensus state in a given time. This protocol could be applied to reaching consensus in decentralized cryptocurrency systems. A special feature of it is that it makes use of a sequence of random numbers which are either provided by a trusted source or generated by the nodes themselves using some decentralized random number generating protocol. This increases the overall trustworthiness of the infrastructure. A core contribution of the paper is that it uses a very weak consensus to obtain a strong consensus on the value of a bit, and which can relate to the validity of a transaction.
In the last few years, two technological events emerged. First, the rising of Industry 4.0 concepts and technologies such as IoT allowed the direct link between machines on the shop floor, establishing a machine-to-machine communication (M2M). Second, blockchain enables transactions such payments and contracts without a formal reliable or accreditation institutions, such as banks or government. Goal: The goal of this paper is to explore the state-of-art of the blockchain technology applied to the manufacture sector. In this sense, the option of the M2M transaction being intermediated by blockchain on the shop floor is a hypothesis to be tested. Moreover, it could be questioned if these subjects are being appreciated by the academia. Design / Methodology / Approach: a systematic review of the literature was conducted, considering blockchain, the industrial context, and the Industry 4.0 related technologies. Results: As a result, only 12 papers that were classified according to their application fields and practice stages were obtained. Limitations of the investigation: this field of application is brand new; thus, the available literature is scarce; only 12 papers were obtained. Practical implications: As the main result, it was identified that the possibilities of blockchain applications to Industry have been poorly explored by literature. Originality / Value: The paper addresses the possibility of application of blockchain in M2M-based manufacture, and detaches the research gap in the academic literature related to it.
João Antônio Aparecido Cardoso, Felipe Takeshi Ishizu, Jeferson Tadeu De Lima, Jefferson de Souza Pinto
Goal: The present work aims to present how the use of a blockchain two-factor authentication solution 2FA on a page developed on WordPress can contribute to the information security regarding user authentication. Design/Methodology/Approach: The research method employed is characterized as an exploratory research, since all the analysis is based on the theoretical reference data available on the subject. A field research was carried out in relation to the implementation of the multi-factor authentication plugin Hydro Raindrop MFA, which uses blockchain technology offered by The Hydrogen Technology Corporation and the Project Hydro platform over the Ethereum network. Thus, this paper sought to present and conceptualize some of the technologies used, pointing out their contribution to information security. Results: The main results showed that the use of decentralized technology, such as blockchain and the Hydro Raindrop Plugin, can contribute considerably in the process of user authentication, which may strengthen the safeguard of the information and assets of individuals and organizations by inhibiting or reducing the possibility of successful a hacker attack. This solution is at the forefront of innovation with regard to data security because it uses advanced blockchain technology. It might contribute in a satisfactory way to the preservation of critical data and information that are the core value of many organizations of the industry 4.0. Limitations of the investigation: This research was limited to analyzing how the implementation of the Hydro Raindrop multi-factor authentication solution on a WordPress page can be beneficial to ensure information security. Practical implications: This study’s findings can contribute to entities interested in cybersecurity. As a suggestion for future works, analyses of plugins or similar solutions available on the market in distinct types of websites, or performance comparisons between them, may be relevant to contribute to scientific research. Originality/Value: This work can contribute in an innovative way to scientific research, since it addresses a recently created solution that uses blockchain technology as its basis for a safer method of authentication.
Sandra Johnson, Peter Robinson, Kishore Atreya, Claudio Lisco
Supply chains lend themselves to blockchain technology, but certain challenges remain, especially around invoice financing. For example, the further a supplier is removed from the final consumer product, the more difficult it is to get their invoices financed. Moreover, for competitive reasons, retailers and manufacturers do not want to disclose their supply chains. However, upstream suppliers need to prove that they are part of a `stable' supply chain to get their invoices financed, which presents the upstream suppliers with huge, and often unsurmountable, obstacles to get the necessary finance to fulfil the next order, or to expand their business. Using a fictitious supply chain use case, which is based on a real world use case, we demonstrate how these challenges have the potential to be solved by combining more advanced and specialised blockchain technologies with other technologies such as Artificial Intelligence. We describe how atomic crosschain functionality can be utilised across private blockchains to retrieve the information required for an invoice financier to make informed decisions under uncertainty, and consider the effect this decision has on the overall stability of the supply chain.
Blockchain technology is on the rise and considered to be a revolutionary technology. It has been applied to many domains including personal health records, regulatory investigation, and global supply chain. Applications that may potentially benefit from blockchain technology are those, which involve multiple parties across the different organization, each performing a subset of many steps needed to complete a given transaction and involve different technologies. In addition, security and trust is a major concern. Given this, a good candidate for blockchain technology is mortgage lending. The purpose of this paper is to prepare a model that identifies different elements that are needed when applying blockchain technology in the mortgage origination process. This paper uses a popular framework used in customer relationship management (CRM) that combines three constructs: People, Process and Technology to develop the intended model.
Perkembangan teknologi meghadirkan banyak inovasi. Salah satu inovasi teknologi adalah berkembangnya Cryptocurrency atau mata uang Kripto. Salah satu jenis Cryptocurrency adalah Bitcoin. Karena beberapa faktor, Bitcoin menjadi terkenal di seluruh dunia, sehingga sering diperdagangkan layaknya perdagangan mata uang pada umumya. Namun karena belum adanya regulasi dari pemerintah, membuat harga bitcoin menjadi tidak terkendali sehingga sering terjadi fluktuasi besar besaran. Metode Double Exponential Smoothing adalah sebuah metode yang sering diguakan dalam kebutuhan Forecastng. Metode ini memanfaatka data historis pada priode tertentu dalam proses prediksi. Untuk metode ini akan diuji dalam sebuah rancangan dan pengembangan system berbasis web, dimana sampel data akan di kalkulasikan dengan Metode Double Exponential Smoothing. Penelitian ini menguji sekitar 5 data setiap harinya selama 10 hari, dengan parameter a (alpha) 0.4035. menghasilkan tingkat akurasi senilai 70%. Hasil peramalan itu akan di sajikan dalam bentuk tabel dan grafik. Key Words : Bitcoin, Forecasting, Double Exponential Smoothing, Kurs, Cryptocurrency
Bitcoin is a top-ranked cryptocurrency that has experienced huge growth and survived numerous attacks. The protocols making up Bitcoin must therefore accommodate the growth of the network and ensure security. Security of the Bitcoin network depends on connectivity between the nodes. Higher connectivity yields better security. In this paper we make two observations: (1) current connectivity in the Bitcoin network is too low for optimal security; (2) at the same time, increasing connectivity will substantially increase the bandwidth used by the transaction dissemination protocol, making it prohibitively expensive to operate a Bitcoin node. Half of the total bandwidth needed to operate a Bitcoin node is currently used to just announce transactions. Unlike block relay, transaction dissemination has received little attention in prior work. We propose a new transaction dissemination protocol, Erlay, that not only reduces the bandwidth consumption by 40% assuming current connectivity, but also keeps the bandwidth use almost constant as the connectivity increases. In contrast, the existing protocol increases the bandwidth consumption linearly with the number of connections. By allowing more connections at a small cost, Erlay improves the security of the Bitcoin network. And, as we demonstrate, Erlay also hardens the network against attacks that attempt to learn the origin node of a transaction. Erlay is currently being investigated by the Bitcoin community for future use with the Bitcoin protocol.
Yongjun Ren, Yan Leng, Fujian Zhu, Jin Wang · 5 authors
Wireless body area networks (WBANs) are expected to play a vital role in the field of patient-health monitoring shortly. They provide a convenient way to collect patient data, but they also bring serious problems which are mainly reflected in the safe storage of the collected data. The privacy and security of data storage in WBAN devices cannot meet the needs of WBAN users. Therefore, this paper adopts blockchain technology to store data, which improves the security of the collected data. Moreover, a storage model based on blockchain in WBAN is proposed in our solution. However, blockchain storage brings new problems, for example, that the storage space of blockchain is small, and the stored content is open to unauthorized attackers. To solve the problems above, this paper proposed a sequential aggregate signature scheme with a designated verifier (DVSSA) to ensure that the user's data can only be viewed by the designated person and to protect the privacy of the users of WBAN. In addition, the new signature scheme can also compress the size of the blockchain storage space.