Enhancing Privacy and Improving Security in Scalable Blockchain (original) (raw)
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Increasing Anonymity in Bitcoin
Lecture Notes in Computer Science, 2014
Bitcoin prevents double-spending using the blockchain, a public ledger kept with every client. Every single transaction till date is present in this ledger. Due to this, true anonymity is not present in bitcoin. We present a method to enhance anonymity in bitcoin-type cryptocurrencies. In the blockchain, each block holds a list of transactions linking the sending and receiving addresses. In our modified protocol the transactions (and blocks) do not contain any such links. Using this, we obtain a far higher degree of anonymity. Our method uses a new primitive known as composite signatures. Our security is based on the hardness of the Computation Diffie-Hellman assumption in bilinear maps.
Privacy and Anonymity Preserving Challenges in Bit Coin Transactions
2018
Bitcoin emerged as decentralized peer-to-peer (P2P) cryptocurrency, not under the hood of any ascendant obligation and is completely digital not backed by any physical commodity. The ownership of the money in Bitcoin form is completely anonymous and private. To prevent double-spending, Bitcoin uses asymmetric cryptography to create ownership of funds as well as proof-of-work (PoW) for making a transaction backed by P2P storage of transaction log in the form of distributed append-only public ledger called blockchain. Every transaction is digitally signed using public key cryptography and is irreversible and secure. Bitcoin transactions have to rely on global peer-to-peer network of participants who help to validate and certify each transaction in a decentralized system. The participating peers acting as miners certify validity of transaction by proving the ownership of the fund from the blockchain. If endorsed, it now completes new data block to add to the blockchain. This new data b...
Electronics
A permissioned blockchain includes a user in the network after verifying the user’s identity, in contrast to Bitcoin, which is a public blockchain that allows network participation without third-party approval. The two types of permissioned blockchains are private blockchains, each consisting of one server and multiple users, and consortium blockchains, which consist of groups of private blockchains. However, a blockchain has privacy issues, such as user tracking and inference. Therefore, cryptography should be applied for user privacy in a blockchain. There is a lot of research on anonymous protocols for privacy in a blockchain. In this paper, we provide a scheme for user management, i.e., identification and authorization, in a permissioned blockchain. We also propose an anonymous protocol with user identification and transaction linking capabilities provided by the private server, strictly to solve privacy concerns.
Privacy Protection Issues in Blockchain Technology
IJCSIS Vol 17 No 2, 2019
Blockchain is an innovative application model that integrates consensus mechanisms, distributed data storage, point-to-point transmission, digital encryption technology and many other computer technologies. It has the characteristics of being decentralized, safe, reliable, open and transparent. In blockchain, digital encryption technology occupies the core position. The security of user information and transaction data is the necessary condition for the popularization of blockchain, and the development of cryptography technology promotes and restricts the further development of blockchain. This article describes the whole infrastructure of the blockchain with its different layers such as data, network, consensus, contract and finally application. Taking the bitcoin running process as an example, this paper analyzes the problems that the blockchain still has in the aspect of privacy protection, and introduces the existing solutions to these problems, including the mixed coin mechanism, 0 knowledge certificate, Ring signature and other technologies, expounds the outstanding problems and makes a prospect.
An advanced Decentralized Conditional Anonymous Payment System for Cryptocurrency using Blockchain
2021
Blockchain, a circulated record innovation, can possibly be conveyed in a wide scope of utilizations. Among these applications, decentralized payment frameworks (for example Bitcoin) have been perhaps the most developed blockchain applications with inescapable appropriation. While the early plans (for example Bitcoin) are regularly the cash of decision by cybercriminals, they just give pseudo-secrecy, as in anybody can de-anonymize Bitcoin exchanges by utilizing data in the blockchain. To reinforce the security insurance of decentralized payment frameworks, various arrangements, for example, Monero and Zerocash have been proposed. Notwithstanding, totally Decentralized Anonymous Payment (DAP) frameworks can be criminally misused, for instance in online coercion and illegal tax avoidance exercises. Perceiving the significance of guideline, we present a novel meaning of Decentralized Conditional Anonymous Payment (DCAP) and portray the comparing security necessities. To develop a soli...
SoK: Research Perspectives and Challenges for Bitcoin and Cryptocurrencies
—Bitcoin has emerged as the most successful cryptographic currency in history. Within two years of its quiet launch in 2009, Bitcoin grew to comprise billions of dollars of economic value despite only cursory analysis of the system's design. Since then a growing literature has identified hidden-but-important properties of the system, discovered attacks, proposed promising alternatives, and singled out difficult future challenges. Meanwhile a large and vibrant open-source community has proposed and deployed numerous modifications and extensions. We provide the first systematic exposition Bitcoin and the many related cryptocurrencies or 'altcoins.' Drawing from a scattered body of knowledge, we identify three key components of Bitcoin's design that can be decoupled. This enables a more insightful analysis of Bitcoin's properties and future stability. We map the design space for numerous proposed modifications , providing comparative analyses for alternative consensus mechanisms, currency allocation mechanisms, computational puzzles, and key management tools. We survey anonymity issues in Bitcoin and provide an evaluation framework for analyzing a variety of privacy-enhancing proposals. Finally we provide new insights on what we term disintermediation protocols, which absolve the need for trusted intermediaries in an interesting set of applications. We identify three general disintermediation strategies and provide a detailed comparison.
2017 15th Annual Conference on Privacy, Security and Trust (PST), 2017
The most fundamental purpose of blockchain technology is to enable persistent, consistent, distributed storage of information. Increasingly common are authentication systems that leverage this property to allow users to carry their personal data on a device while a hash of this data is signed by a trusted authority and then put on a blockchain to be compared against. For instance, in 2015, MIT introduced a schema for the publication of their academic certificates based on this principle. In this work, we propose a way for users to obtain assured identities based on face-to-face proofing that can then be validated against a record on a blockchain. Moreover, in order to provide anonymity, instead of storing a hash, we make use of a scheme of Brands to store a commitment against which one can perform zero-knowledge proofs of identity. We also enforce the confidentiality of the underlying data by letting users control a secret of their own. We show how our schema can be implemented on Bitcoin's blockchain and how to save bandwidth by grouping commitments using Merkle trees to minimize the number of Bitcoin transactions that need to be sent. Finally, we describe a system in which users can gain access to services thanks to the identity records of our proposal.
Anonymous Alone? Measuring Bitcoin’s Second-Generation Anonymization Techniques
2017 IEEE European Symposium on Security and Privacy Workshops (EuroS&PW), 2017
This paper contributes a systematic account of transaction anonymization techniques that do not require trust in a single entity and support the existing cryptographic currency Bitcoin. It surveys and compares four known techniques, proposes tailored metrics to identify the use of each technique (but not necessarily its users), and presents longitudinal measurements indicating adoption trends and teething troubles. There is a tradeoff between the choice of users' preferred protection mechanisms and the risk that pertaining transactions can be singled out, which hurts privacy due to smaller anonymity sets unless a critical mass adopts the mechanism.
Data Privacy Management, Cryptocurrencies and Blockchain Technology
Lecture Notes in Computer Science, 2017
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Transparency and Protection of Personal Data in the Blockchain.
2021
Every day there are more threats in the violation of personal data, where privacy and security of information are the main challenge in this age of information and communication. Thus, Blockchain technology comes as a revolution due to its characteristics of immutability, trust, transparency, decentralization and distribution in the registers, turning it into a disruptive technology that breaks traditional paradigms about how we perceive the world. In its development and application, it raises many questions, mainly with the compatibility, with privacy and protection of personal data, which is why we will examine in a general way how this disruptive technology works, the intersection it has with the legal norms and the possible crossroads they must dialogue and resolve so that people are true owners of their identity and personal data.