Blockchain Papers

Wenming Wang, Haiping Huang, Lingyan Xue, Qi Li · 6 authors

No abstract is available for this record.

Anusha Vangala, Anil Kumar Sutrala, Ashok Kumar Das, Minho Jo

A blockchain-based smart farming technology provides the agricultural data to the farmers and other users associated with smart farming on a single integrated platform. Moreover, persistence and auditability of stored data in blocks into the blockchain provide the confidence of using the correct data when needed later and adds transparency, anonymity, and traceability at the same time. To fulfill such a goal, in this article, we design a new smart contract-based blockchain-envisioned authenticated key agreement mechanism in a smart farming environment. The device-to-device (D2D) authentication phase and device-to-gateway (D2G) authentication phase support mutual authentication and key agreement between two Internet-of-Things (IoT)-enabled devices and between an IoT device and the gateway node (GWN) in the network, respectively. The blocks are created by the edge servers on the authenticated data of IoT devices received from the GWNs and then sent to the cloud server (CS). The smart contract-based consensus mechanism allows verification and addition of the formed blocks by a peer-to-peer (P2P) CSs network. The security of the proposed scheme is done through formal and informal security analysis, and also using the formal security verification tool. A detailed comparative study reveals that the proposed scheme offers superior security and more functionality features as compared to existing competing authentication protocols. Finally, the blockchain-based simulation has been conducted to measure computational time for a varied number of mined blocks and also a varied number of transactions per block.

Chin‐Ling Chen, Yong‐Yuan Deng, Wei Weng, Ming Zhou · 5 authors

No abstract is available for this record.

Zaher Haddad, Mohamed Baza, Mohamed Mahmoud, Waleed Alasmary · 5 authors

The fifth generation (5G) cellular network provides users with high-quality services due to its high transmission rate and low latency. It will support Internet of Things (IoT) devices and enable new applications in health, banking, education, etc. Security is essential in this network because vulnerabilities may be exploited to disrupt these applications which may directly impact our life. Authentication and key agreement (AKA) and handover (HO) are usually the target of cyberattacks in any cellular network. On the other hand, blockchain is a peer-to-peer network that aims to maintain an immutable and secure ledger. This new technology will be used widely to secure many applications. This paper aims to develop an efficient and secure AKA scheme and uniform handover protocol for 5G network using blockchain. The home network (HN) is not involved in the AKA scheme and HO protocol to protect the HN from attacks, such as denial of service (DoS) attacks, and also lower the communication and computation overhead. Moreover, our HO protocol is uniform in the sense that it can be used for all HO scenarios. The protocol is also efficient because it requires exchanging a few amount of data. It can also achieve forward/backward secrecy. Furthermore, the blockchain is used to verify the public keys of the network nodes which is necessary to secure our AKA scheme and HO protocol. It also records the locations of the users which is necessary for the functionality of the network. Our evaluations demonstrate that the proposed HO protocol is secure, uniform, and can achieve the forward/backward secrecy. Furthermore, our AKA scheme requires lower computation and computation overhead comparing to the existing schemes, and preserves the energy of the limited-energy mobile devices.

Emre Karakoç, Danışman: Prof. Dr. Celal Çeken

Kablolu ortamda Yazılım Tanımlı Ağ (YTA) teknolojisinin başarısı, Kablosuz Algılayıcı Ağlar (KAA) üzerinde YTA'nın konuşlandırılmasına ilişkin araştırmaları hızlandırmıştır. Kablosuz ortamın paylaşımlı bir doğası olduğundan, yönlendirme saldırılarına karşı daha savunmasızdır. Kablosuz ortamın fiziksel kısıtlamaları ve ağdaki düğümlerin sınırlı enerjisi, işleme kapasitesi ve belleği olduğundan, mevcut güvenlik protokollerinin çoğu KAA için uygulanamaz. Bu çalışma ile değişmezlik ve şeffaflık ilkesini temel alan Blokzincir teknolojisi ele alındı. YTA tabanlı KAA üzerinde Blokzincir teknolojisi uygulanarak enerji dostu yeni bir güvenlik modeli geliştirildi. YTA tabanlı KAA'daki olası tehditler araştırıldı ve önerilen modelin güvenirliğini ispat etmek için Kara Delik saldırısı ile model ayrıntılı analiz edildi. Ayrıca önerilen model üzerinde bir Blokzincir teknolojisi olan Akıllı Sözleşmeler kullanıldı. Üretici, hizmet sağlayıcı ve müşterinin taraf olduğu yeni bir güvenli SLA yönetim modeli geliştirildi. Önerilen model güvenilir ürün yaşam döngüsü ve güvenilir SLA sözleşmeleri içermektedir. Önerilen modeldeki yenilikçi yaklaşım sayesinde müşteri ile servis sağlayıcı arasındaki olası anlaşmazlıklar ortadan kaldırıldı. Böylece üretilen ürünün kullanım aşamasında kurcalanabilirlik açısından güvenilirliği sağlandı. Önerilen model var olan modele kıyasla ek veri iletim gecikmesi ve enerji tüketiminde artış meydana getirse de elde edilen simülasyon sonuçları aradaki yüzdesel farkın önemsenmeyecek seviyede (

Yu Chen, Qiang Tang, Yuyu Wang

No abstract is available for this record.

Tarik Hidar, Anas Abou El Kalam, Siham Benhadou, Oussama Mounnan

Since the Tactile Internet has been considered as a new era of Internet, delivering real-time interactive systems as well as ultra-reliable and ultra-responsive network connectivity, tremendous efforts have been made to ensure authentication between communication’s parties to secure remote surgery. Since this human to machine interaction like remote surgery is critical and the communication between the surgeon and the tactile actor i.e. robot arms should be fully protected during the surgical procedure, a fully secure mutual user authentication scheme should be used in order to establish a secure session among the communicating parties. The existing methods usually require a server to ensure the authentication among the communicating parties, which makes the system vulnerable to single of point failure and not fit the design of such critical distributed environment i.e. tactile internet. To address these issues, we propose a new decentralized blockchain based authentication solution for tactile internet. In our proposed solution, there is no need for a trusted party; moreover, the decentralized nature of our proposed solution makes the authentication immutable, efficient, secure, and low latency requirement. The implementation of our proposed solution is deployed on Ethereum official test network Ropsten. The experimental results show that our solution is efficient, highly secured, and flexible.

Thomas Kerber, Aggelos Kiayias, Markulf Kohlweiss

No abstract is available for this record.

Veronika Kuchta, Amin Sakzad, Ron Steinfeld, Joseph K. Liu

No abstract is available for this record.

Julia Hesse, Dennis Hofheinz, Lisa Kohl, Roman Langrehr

We investigate the quality of security reductions for non-interactive key exchange (NIKE) schemes. Unlike for many other cryptographic building blocks (like public-key encryption, signatures, or zero-knowledge proofs), all known NIKE security reductions to date are non-tight, i.e., lose a factor of at least the number of users in the system. In that sense, NIKE forms a particularly elusive target for tight security reductions. The main technical obstacle in achieving tightly secure NIKE schemes are adaptive corruptions. Hence, in this work, we explore security notions and schemes that lie between selective security and fully adaptive security. Concretely: We exhibit a tradeoff between key size and reduction loss. We show that a tighter reduction can be bought by larger public and secret NIKE keys. Concretely, we present a simple NIKE scheme with a reduction loss of O(N2log (ν) / ν2), and public and secret keys of O(ν) group elements, where N denotes the overall number of users in the system, and ν is a freely adjustable scheme parameter. Our scheme achieves full adaptive security even against multiple “test queries” (i.e., adversarial challenges), but requires keys of size O(N) to achieve (almost) tight security under the matrix Diffie-Hellman assumption. Still, already this simple scheme circumvents existing lower bounds. We show that this tradeoff is inherent. We contrast the security of our simple scheme with a lower bound for all NIKE schemes in which shared keys can be expressed as an “inner product in the exponent”. This result covers the original Diffie-Hellman NIKE scheme, as well as a large class of its variants, and in particular our simple scheme. Our lower bound gives a tradeoff between the “dimension” of any such scheme (which directly corresponds to key sizes in existing schemes), and the reduction quality. For ν= O(N), this shows our simple scheme and reduction optimal (up to a logarithmic factor). We exhibit a tradeoff between security and key size for tight reductions. We show that it is possible to circumvent the inherent tradeoff above by relaxing the desired security notion. Concretely, we consider the natural notion of semi-adaptive security, where the adversary has to commit to a single test query after seeing all public keys. As a feasibility result, we bring forward the first scheme that enjoys compact public keys and tight semi-adaptive security under the conjunction of the matrix Diffie-Hellman and learning with errors assumptions. We believe that our results shed a new light on the role of adaptivity in NIKE security, and also illustrate the special role of NIKE when it comes to tight security reductions.

Prabhanjan Ananth, Gilad Asharov, Hila Dahari, Vipul Goyal

Abstract It is well known that several cryptographic primitives cannot be achieved without a common reference string (CRS). Those include, for instance, non-interactive zero-knowledge for NP, or maliciously secure computation in fewer than four rounds. The security of those primitives heavily relies on the assumption that the trusted authority, who generates the CRS, does not misuse the randomness used in the CRS generation. However, we argue that there is no such thing as an unconditionally trusted authority and every authority must be held accountable for any trust to be well-founded. Indeed, a malicious authority can, for instance, recover private inputs of honest parties given transcripts of the protocols executed with respect to the CRS it has generated. While eliminating trust in the trusted authority may not be entirely feasible, can we at least move towards achieving some notion of accountability? We propose a new notion in which, if the CRS authority releases the private inputs of protocol executions to others, we can then provide a publicly-verifiable proof that certifies that the authority misbehaved. We study the feasibility of this notion in the context of non-interactive zero knowledge and two-round secure two-party computation.

Soumyashree S. Panda, Debasish Jena, Bhabendu Kumar Mohanta, Srikanta Patnaik

With the omnipresence of technology, intelligent transportation system (ITS) is no more a distant dream but has become an achievable reality. One of the fundamental challenges in the implementation of an ITS is the proper management of security and privacy issues, especially how the system confirms the validity of its users. Most of the existing security mechanisms are based on a centralized framework and assume the registration authority and roadside units to be trustful. Therefore, a distributed framework using Blockchain and, a very lightweight and privacy-preserving authentication protocol employing an interactive zero-knowledge proof (ZKP) based on elliptic curve cryptography (ECC) is proposed. An in-depth analysis of the protocol demonstrates that it meets all the security and privacy requisites of an ITS. In addition, the suggested protocol is also validated using the widely used AVISPA tool. The reliability and effectiveness of the protocol are analyzed through simulation using NS2 which proves the practicality of the protocol.

Yilei Chen, Alex Lombardi, Fermi Ma, Willy Quach

No abstract is available for this record.

Olivier Blazy, Xavier Bultel, Pascal Lafourcade, Octavio Pérez Kempner

No abstract is available for this record.

Thomas Haines, Johannes Müller

No abstract is available for this record.

Julien Devigne, Céline Duguey, Pierre-Alain Fouque

No abstract is available for this record.

E. A. Shliakhtina, Dennis Gamayunov

In this paper, we address the problem of mutual authentication in user groups in decentralized messaging systems without trusted third party. We propose a mutual authentication algorithm for groups using zero-knowledge proof. Using the algorithm, which is based on trust chains existing in decentralized network, users are able to authenticate each other without establishing a shared secret over side channel. The proposed algorithm is based on Democratic Group Signature protocol (DGS) and Communication-Computation Efficient Group Key algorithm for large and dynamic groups (CCEGK). We have performed security analysis of the proposed mutual authentication scheme against several attacks including Sybil attack and have made complexity estimation for the algorithm. The algorithm is implemented in an experimental P2P group messaging application, and using this implementation we estimate overhead of the authentication scheme and convergence time for several initial configurations of user groups and trust chains.

Xiao Liang, Omkant Pandey

General-purpose zero-knowledge proofs for all \(\mathsf {NP} \) languages greatly simplify secure protocol design. However, they inherently require the code of the underlying relation. If the relation contains black-box calls to a cryptographic function, the code of that function must be known to use the ZK proof, even if both the relation and the proof require only black-box access to the function. Rosulek (Crypto’12) shows that non-trivial proofs for even simple statements, such as membership in the range of a one-way function, require non-black-box access.

Xavier Salleras, Vanesa Daza

Zero-Knowledge Proofs (ZKPs) are cryptographic primitives allowing a party to prove to another party that the former knows some information while keeping it secret. Such a premise can lead to the development of numerous privacy-preserving protocols in different scenarios, like proving knowledge of some credentials to a server without leaking the identity of the user. Even when the applications of ZKPs were endless, they were not exploited in the wild for a couple of decades due to the fact that computing and verifying proofs was too computationally expensive. However, the advent of efficient schemes (in particular, zk-SNARKs) made this primitive to break into the scene in fields like cryptocurrencies, smart-contracts, and more recently, self-sovereign scenarios: private-by-design identity management and authentication. Nevertheless, its adoption in environments like the Internet of Things (IoT) remains unexplored due to the computational limitations of embedded systems. In this paper, we introduce ZPiE, a C library intended to create ZKP applications to be executed in embedded systems. Its main feature is portability: it can be compiled, executed, and used out-of-the-box in a wide variety of devices. Moreover, our proof-of-concept has been proved to work smoothly in different devices with limited resources, which can execute state-of-the-art ZKP authentication protocols.

Su-Min Yoo, Soo-Bin Yoo, Jung-Hwa Jo, Ae-Seon Son

현대 사회에서는 인터넷 상의 데이터 유출을 보장하면서 데이터 송 수신자들의 증명을 확인시켜 주는 공개키 기반구조(Public Key Infrastructure)를 활용하여, 온라인상에서 안전한 데이터 교환과 신원인증을 위해서 대칭키, 비대칭키 암호화 기반의 디지털 인증서 기술을 제공하고 있다. 하지만 CA(Certificate Authority, 인증기관)의 보안이 취약하다면 CA의 디지털 인증서를 사용하는 모든 사용자들 또한 데이터 유출에 취약해지며, 또한 유출된 정보로 인해 발생할 수 있는 2차적인 피해가 있다. 본 논문은 디지털 인증서 와 키 유출로 인한 피해를 방지하기 위해 자기주권 신원증명 기술을 활용하여 분산 원장 환경인 블록체인을 사용하여 데이터의 무결성을 보장하고 블록체인에 등록된 DID(Decentralized Identifier) Document의 공개키를 사용하여 탈중앙화 구조에서 안전하게 공개키를 교환할 수 있는 보안성을 확보하는 체계를 제안한다.

Oliver Kattwinkel, Michael Rademacher

In 2008, the cryptocurrency Bitcoin, which is equivalent to the original idea of a blockchain, emerged as a new currency and revolutionized the digital exchange of value. Despite the great user and research interest, the customary practice is still complex. Poor usability and negative user experience lead to several security threats. This work examines the mitigation of third party attack vectors and non-malicious human failure types identified in the personal payment process. Current approaches are analyzed and a new payment protocol is specified to foster the exchange of preparatory payment information. The qualitative evaluation reveals a significant improvement over the current best-practice exchange procedure. The system demonstrates a balance between security and usability and provides a method for more user-friendly blockchain transactions.

Altynbek Seitenov, Gulnur Smagulova

Abstract: In the contemporary world, Ethereum is a very reliable financial saving among cryptocurrencies. It is also well known as a blockchain platform for creating and launching its own cryptocurrency. The applications run on Ethereum executed by a platform-specific cryptographic token, ether. During 2014, Ethereum had launched a pre-sale for ether, which had received an overwhelming response. Ether is used broadly for two purposes: it is traded as a digital currency exchange like other cryptocurrencies, and it is used inside Ethereum to run applications and even to monetize work. It should be noticed that the smart contract has brought a significant share of the success to Ethereum. The smart contract is a computer programme that independently performs assigned tasks between network participants without the participation of a third trusted party. Smart contracts and their intranet transactions have facilitated the rapid expansion of the Ethereum network. Smart contracts are widely represented on the market, either as electronic transaction payments or as applications for the implementation of logistics supplies, gambling, and other sectors. These transactions are irreversible and fully tracked online. Whereas the electronic records are available in a public distributed ledger and include data about user addresses, whereas the real names are hidden. The article explains the usage of decentralized accounts and their electronic transactions in the Ethereum network. The results are presented through different application sectors. Additionally, a new method for extracting blockchain records through node cluster via IPFS path is implemented in the research.

Mubarak Umar, Zhenqiang Wu, Xuening Liao

No abstract is available for this record.

Basudeb Bera, Ashok Kumar Das, Mohammad S. Obaidat, Pandi Vijayakumar · 6 authors

In Internet of Everything (IoE), malicious attacks detection and mitigation are important issues. These issues can be resolved through an access control framework where two entities first authenticate each other prior to establishing any secret key for their secure communication. The sensing data of various smart devices in an IoE environment are processed securely at the nearby fog servers and at the same time legitimate users can also access the real-time data directly from designated smart devices through access control mechanism. We first discuss various attack trends in an IoE environment. After that, we discuss evolution of the blockchain technology in the IoE. An artificial intelligence based blockchain-envisioned access control framework for malicious attacks detection and mitigation has been suggested to secure the IoE environment. Finally, a blockchain-based implementation has been conducted on the proposed blockchain-envisioned access control framework for measuring the computational time needed for varying number of blocks mined in the blockchain and also for varying number of transactions per block.