BLOCKCHAINS IN NATIONAL DEFENSE: TRUSTWORTHY SYSTEMS IN A TRUSTLESS WORLD

Download here : Blockchains In National Defense: Trustworthy Systems In  A Trustless World

Source : http://www.dtic.mil/doctrine/education/jpme_papers/barnas_n.pdf

Extract from Abstract

The   ability   of the  USAF  to  prevail   in  the highly  contested  environment of 2040  will  be dictated by  its   ability   to   defend   cyber enabled  systems ,  and the  data within  them,  from compromise and manipulation.Yet contemporary  cyber defense  is faltering,  and incremental improvement s   seem  unlikely  to overcome   an  exponentially    growing   cyber  threat.    Thus,  an  entirely  new  model  for  cyber  defense  strategy  is  needed thats met by BLOCKCHAIN.   

Author Details
Neil  B. Barnas,  Major, USAF

HashGraph : An overview with example

Hashgraph is a superior consensus mechanism / data structure alternative to blockchain. A decentralized platform without servers built on Hashgraph technology will enable blockchain use cases to run:safe,secure and Fast.This pdf is a straight lift from http://www.swirlds.com

Hashgraph : An over view with example from anupriti

What is a Smart Contract? A Beginner’s Guide

A non technical,easy over view of what simply a Smart Contract means? Smart contracts help you exchange money, property, shares, or anything of value in a transparent, conflict-free way, while avoiding the services of a middleman. The best way to describe smart contracts is to compare the technology to a vending machine. Ordinarily, you would go to a lawyer or a notary, pay them, and wait while you get the document. With smart contracts, you simply drop a bitcoin into the vending machine (i.e. ledger), and your escrow, driver’s license, or whatever drops into your account. More so, smart contracts not only define the rules and penalties around an agreement in the same way that a traditional contract does, but also automatically enforce those obligations.

TRANSACTION MALLEABILITY : SIMPLY

Although little old video...but is good to give an easy to understand explanation on What Transaction Malleability is?

TRANSACTION MALLEABILITY : A DEMO TO GET AN OVERVIEW OF WHAT IT IS?

This is a demo of  presentation "Bitcoin Transaction Malleability" Theory in Practice" by Daniel Chechik. The demo simulates a trading website that is vulnerable to Transaction Malleability, by simply not following the transaction correctly. The attacker can exploit this vulnerability to receive more coins to his personal wallet than he originally should have in the first place.

SEGWIT EXPLAINED SIMPLY

An easy non technical overview of what SEGWIT is all about.Technical users can herein after dwell deeper..

QUANTUM ATTACKS ON BITCOIN, AND HOW TO PROTECT AGAINST THEM

Download here : Quantum attacks on Bitcoin, and how to protect against them

Source : https://arxiv.org/pdf/1710.10377.pdf

Extract from Abstract

The key cryptographic protocols used to secure the internet and financial transactions of today are all susceptible to attack by the development of a sufficiently large quantum computer. One particular area at risk are cryptocurrencies, a market currently worth over 150 billion USD. We investigate the risk of Bitcoin, and other cryptocurrencies, to attacks by quantum computers. We find that the proof-of-work used by Bitcoin is relatively resistant to substantial speedup by quantum computers in the next 10 years, mainly because specialized ASIC miners are extremely fast compared to the estimated clock speed of near-term quantum computers. On the other hand, the elliptic curve signature scheme used by Bitcoin is much more at risk, and could be completely broken by a quantum computer as early as 2027, by the most optimistic estimates. We analyze an alternative proof-of-work called Momentum, based on finding collisions in a hash function, that is even more resistant to speedup by a quantum computer. We also review the available post-quantum signature schemes to see which one would best meet the security and efficiency requirements of blockchain applications.

Author Details

Divesh  Aggarwal,Gavin  K.  Brennen,Troy Lee,Miklos  Santha and  Marco  Tomamichel at National University of Singapore, Singapore and Centre for Quantum Technologies, National University of Singapore, Singapore

BYZANTINE GENERALS AND HOW IS IT RELATED TO BITCOIN AND ETHEREUM?

An excellent video by Evan about What is the story of Byzantine Generals and how is it related to Bitcoin and Ethereum? 

Listen it with patience and you are bound to value add your understanding about the same if not already clear...

THE BITCOIN BACKBONE PROTOCOL:ANALYSIS AND APPLICATIONS

Download here : The Bitcoin Backbone Protocol:Analysis and Applications

Source : https://eprint.iacr.org/2014/765.pdf

Extract from Abstract

Bitcoin is the first and most popular decentralized cryptocurrency to date. In this work, we extract and analyze the core of the Bitcoin protocol, which we term the Bitcoin backbone , and prove two of its fundamental properties which we call common prefix and chain quality in the static setting where the number of players remains fixed. Our proofs hinge on appropriate and novel assumptions on the “hashing power” of the adversary relative to network synchronicity; we show our results to be tight under high synchronization.Next, we propose and analyze applications that can be built “on top” of the backbone protocol, specifically focusing on Byzantine agreement (BA) and on the notion of a public transaction ledger. Regarding BA, we observe that Nakamoto’s suggestion falls short of solving it,and present a simple alternative which works assuming that the adversary’s hashing power is bounded by 1/3.The public transaction ledger captures the essence of Bitcoin’s operation as a cryptocurrency, in the sense that it guarantees the liveness and persistence of committed transactions.  Based on this notion we describe and analyze the Bitcoin system as well as a more elaborate BA protocol, proving them secure assuming high network synchronicity and that the adversary’s hashing power is strictly less than 1/2, while the adversarial bound needed for security decreases as the network desynchronizes.Finally, we show that our analysis of the Bitcoin backbone protocol for synchronous networks extends with relative ease to the recently considered “partially synchronous” model, where there is an upper bound in the delay of messages that is unknown to the honest parties.

Author Details

Juan A. Garay
Yahoo Research
garay@yahoo-inc.com

Aggelos Kiayias
University of Edinburgh, IOHK
akiayias@inf.ed.ac.uk

THE ECONOMICS OF BITCOIN

Recorded at the Mises Institute in Auburn, Alabama, on 27 July 2017,views by Malavika Nair who is a assistant professor of economics in the Manuel H. Johnson Center for Political Economy at Troy University, Alabama. Her research focuses on questions related to monetary theory, financial history, private enterprise in money production and financial services, as well as the economics of caste.

DANDELION: REDESIGNING THE BITCOIN NETWORK FOR ANONYMITY

Download here : Dandelion: Redesigning the Bitcoin Network for Anonymity

Source : https://arxiv.org/abs/1701.04439

Extract from Abstract

Bitcoin and other cryptocurrencies have surged in popularity over the last decade. Although Bitcoin does not claim to provide anonymity for its users, it enjoys a public perception of being a `privacy-preserving' financial system. In reality, cryptocurrencies publish users' entire transaction histories in plaintext, albeit under a pseudonym; this is required for transaction validation. Therefore, if a user's pseudonym can be linked to their human identity, the privacy fallout can be significant. Recently, researchers have demonstrated deanonymization attacks that exploit weaknesses in the Bitcoin network's peer-to-peer (P2P) networking protocols. In particular, the P2P network currently forwards content in a structured way that allows observers to deanonymize users. In this work, we redesign the P2P network from first principles with the goal of providing strong, provable anonymity guarantees. We propose a simple networking policy called Dandelion, which achieves nearly-optimal anonymity guarantees at minimal cost to the network's utility. We also provide a practical implementation of Dandelion.

Author Details

Shaileshh Bojja Venkatakrishnan, Giulia Fanti, Pramod Viswanath
at bjjvnkt2@illinois.edu,fanti@illinois.edu and pramodv@illinois.edu

PROOF OF LUCK: AN EFFICIENT BLOCKCHAIN CONSENSUS PROTOCOL

Download here : Proof of Luck: an Efficient Blockchain Consensus Protocol

Source : https://arxiv.org/pdf/1703.05435.pdf

Extract from Abstract

In the paper, we present designs for multiple blockchain consensus primitives and a novel blockchain system, all based on the use of trusted execution environments (TEEs), such as Intel SGX-enabled CPUs. First, we show how using TEEs for existing proof of work schemes can make mining equitably distributed by preventing the use of ASICs. Next, we extend the design with proof of time and proof of ownership consensus primitives to make mining energy- and time-efficient. Further improving on these designs, we present a blockchain using a proof of luck consensus protocol. Our proof of luck blockchain uses a TEE platform's random number generation to choose a consensus leader, which offers low-latency transaction validation, deterministic confirmation time, negligible energy consumption, and equitably distributed mining. Lastly, we discuss a potential protection against up to a constant number of compromised TEEs.

Author Details

Mitar Milutinovic,UC Berkeley,mitar@cs.berkeley.edu
Warren He ,UC Berkeley,-w@berkeley.edu
Howard Wu,UC Berkeley,howardwu@berkeley.edu

LELANTOS: A BLOCKCHAIN-BASED ANONYMOUS PHYSICAL DELIVERY SYSTEM

Download here : Lelantos: A Blockchain-based Anonymous Physical Delivery System

Source : https://eprint.iacr.org/2017/465.pdf

Extract from Abstract

Real  world  physical  shopping  offers  customers  the privilege of maintaining their privacy by giving them the option of  using  cash,  and  thus  providing  no  personal  information such  as  their  names  and  home  addresses.  On  the  contrary,electronic  shopping  mandates  the  use  of  all  sorts  of  personally identifiable information for both billing and shipping purposes. Cryptocurrencies  such  as  Bitcoin  have  created  a  stimulated growth  in  private  billing  by  enabling  pseudonymous  payments. However, the anonymous delivery of the purchased physical goods is still an open research problem.

In  this  work,  we  present  a  blockchain-based  physical  delivery  system  called Lelantos that  within  a  realistic  threat model, offers customer anonymity, fair exchange and merchant customer  unlinkability.  Our  system  is  inspired  by  the  onion routing techniques which are used to achieve anonymous message delivery. Additionally, Lelantos relies on the decentralization and pseudonymity of the blockchain to enable pseudonymity that is hard to compromise, and the distributed consensus mechanisms provided by smart contracts to enforce fair irrefutable transactions between distrustful contractual parties.

Author Details

Riham AlTawy,Muhammad ElSheikh,Amr M. Youssef and Guang Gong
Electrical and Computer Engineering Department, University of Waterloo, Ontario, Canada.
Concordia Institute for Information Systems Engineering, Concordia University, Quebec, Canada

BLOCKCHAIN: A DISTRIBUTED SOLUTION TO AUTOMOTIVE SECURITY AND PRIVACY

Download here : Blockchain: A distributed solution to Automotive Security and Privacy

Source : https://arxiv.org/abs/1704.00073

Extract from Abstract

Interconnected smart vehicles offer a range of sophisticated services that benefit the vehicle owners, transport authorities, car manufacturers and other service providers. This potentially exposes smart vehicles to a range of security and privacy threats such as location tracking or remote hijacking of the vehicle. In this article, we argue that BlockChain (BC), a disruptive technology that has found many applications from cryptocurrencies to smart contracts, is a potential solution to these challenges. We propose a BC-based architecture to protect the privacy of the users and to increase the security of the vehicular ecosystem. Wireless remote software updates and other emerging services such as dynamic vehicle insurance fees, are used to illustrate the efficacy of the proposed security architecture. We also qualitatively argue the resilience of the architecture against common security attacks.

Author Details

Ali Dorri, Marco Steger,Salil S. Kanhere, and Raja Jurdak

This paper is accepted to be published in IEEE Communications Magazine and is subjected to IEEE copyright.

A TRACEABILITY ANALYSIS OF MONERO’S BLOCKCHAIN

Download here : A Traceability Analysis of Monero’s Blockchain

Source : https://eprint.iacr.org/2017/338.pdf

Extract from Abstract

Monero is a cryptocurrency that has rapidly gained popularity since its launch in April 2014. The source of its growth can be mainly attributed to its unique privacy properties that go well beyond the pseudonymity property of cryptocurrencies such as Bitcoin.In this work, we conduct a forensic analysis of the Monero blockchain. Our main goal is to investigate Monero’s untraceability guarantee, which essentially means that given a transaction input,the real output being redeemed in it should be anonymous among a set of other outputs. To this end, we develop three heuristics that lead to simple-to-implement attack routines. We evaluate our attacks on the Monero blockchain and show that in 87% of cases, the real output being redeemed can be easily identfi ed with certainty. Moreover, we have compelling evidence that two of our attacks also extend to Monero RingCTs — the second generation Monero that even hides the transaction value.

Author Details

Amrit Kumar
National University of Singapore
amrit@comp.nus.edu.sg

Clément Fischer
National University of Singapore
cfischer@comp.nus.edu.sg

2-HOP BLOCKCHAIN:COMBINING PROOF-OF-WORK AND PROOF-OF-STAKE SECURELY

Download here : 2-hop Blockchain:Combining Proof-of-Work and Proof-of-Stake Securely

Source : https://eprint.iacr.org/2016/716.pdf

Extract from Abstract

Cryptocurrencies like Bitcoin have proven to be a phenomenal success.  Bitcoin-like systems use proof-of-work mechanism, and their security holds if the majority of the computing power is under the control of honest players. However, this assumption has been seriously challenged recently and Bitcoin-like systems will fail when this assumption is broken.We propose the first provably secure 2-hop blockchain by combining proof-of-work and proof-of-stake mechanisms.  On top of Bitcoin’s brilliant ideas of utilizing the power of the honest miners, via their computing resources, to secure the blockchain, we further leverage the power of the honest users/stakeholders, via their coins/stake, to achieve this goal. The security of our blockchain holds if the honest players control majority of the collective resources (which consists of both computing power and stake).That said, even if the adversary controls more than 50% computing power, the honest players still have the chance to defend the blockchain via honest stake

Author Details

Tuyet Duong,Lei Fan and Hong-Sheng Zhou
available at duongtt3@vcu.edu,fanlei@sjtu.edu.cn
and hszhou@vcu.edu

P2P MIXING AND UNLINKABLE BITCOIN TRANSACTIONS

Download here : P2P Mixing and Unlinkable Bitcoin Transactions

Source : https://eprint.iacr.org/2016/824.pdf

Extract from Abstract

Starting   with   Dining   Cryptographers   networks (DC-net),  several  peer-to-peer  (P2P)  anonymous  communication protocols  have  been  proposed. Despite  their  strong  anonymity guarantees   none   of   those   has   been employed   in   practice   so far:  Most  fail  to  simultaneously  handle  the  crucial  problems of  slot  collisions  and  malicious  peers,  while  the  remaining  ones handle those with a significant increased latency (communication rounds)  linear  in  the  number  of  participating  peers  in  the  best case,  and quadratic in  the  worst  case.  We  conceptualize  these P2P  anonymous  communication  protocols  as P2P  mixing ,  and present a novel P2P mixing protocol, DiceMix, that only requires constant  (i.e.,  four)  communication  rounds  in  the  best  case,  and 4 + 2 rounds  in  the  worst  case  of malicious  peers.  As  every individual malicious peer can prevent a protocol run from success by  omitting  his  messages,  we  find  DiceMix  with  its  worst-case linear-round  complexity  to  be  an  optimal  P2P  mixing  solution.

Author Details

Tim Ruffing
CISPA, Saarland University
tim.ruffing@mmci.uni-saarland.de

Pedro Moreno-Sanchez
Purdue University
pmorenos@purdue.edu

Aniket Kate
Purdue University
aniket@purdue.edu

MIXCOIN : ANONYMITY FOR BITCOIN WITH ACCOUNTABLE MIXES

Download here : Mixcoin :Anonymity for Bitcoin with accountable mixes

Source : https://eprint.iacr.org/2014/077.pdf

Extract from Abstract

We propose Mixcoin, a protocol to facilitate anonymous payments in Bitcoin and similar cryptocurrencies. We build on the emergent phenomenon of currency mixes, adding an accountability mechanism to expose theft. We demonstrate that incentives of mixes and clients can be  aligned  to  ensure  that  rational  mixes  will  not  steal.  Our  scheme  is efficient and fully compatible with Bitcoin. Against a passive attacker,our  scheme  provides  an  anonymity  set  of all other  users  mixing  coins contemporaneously.  This  is  an  interesting  new  property  with  no  clear analog in better-studied communication mixes. Against active attackers our scheme offers similar anonymity to traditional communication mixes.

Author Details

Joseph Bonneau,Arvind Narayanan,Andrew Miller,Jeremy Clark,Joshua A. Kroll and Edward W. Felten

THE BLOCKCHAIN ANOMALY BY CHRISTOPHER NATOLI, VINCENT GRAMOLI

Download here : The Blockchain Anomaly

Source : https://arxiv.org/pdf/1605.05438.pdf

Extract from Abstract

Most popular blockchain solutions, like Bitcoin, rely on proof-of-work, guaranteeing that the output of the consensus is agreed upon with high probability. However, this probability depends on the delivery of messages and that the computational power of the system is sufficiently scattered among pools of nodes in the network so that no pool can mine more blocks faster than the crowd. New approaches, like Ethereum, generalise the proof-of-work approach by letting individuals deploy their own private blockchain with high transaction throughput. As companies are starting to deploy private chains, it has become crucial to better understand the guarantees blockchains offer in such a small and controlled environment. In this paper, we present the \emph{Blockchain Anomaly}, an execution that we experienced when building our private chain at NICTA/Data61. Even though this anomaly has never been acknowledged before, it may translate into dramatic consequences for the user of blockchains. Named after the infamous Paxos anomaly, this anomaly makes dependent transactions, like "Bob sends money to Carole after he received money from Alice" impossible. This anomaly relies on the fact that existing blockchains do not ensure consensus safety deterministically: there is no way for Bob to make sure that Alice actually sent him coins without Bob using an external mechanism, like converting these coins into a fiat currency that allows him to withdraw. We also explore smart contracts as a potential alternative to transactions in order to freeze coins, and show implementations of smart contract that can suffer from the Blockchain anomaly and others that may cope with it.

Author Details

Christopher Natoli
NICTA/Data61-CSIRO
University of Sydney
cnat5672@uni.sydney.edu.au

HAWK: THE BLOCKCHAIN MODEL OF CRYPTOGRAPHY AND PRIVACY-PRESERVING SMART CONTRACTS

Download here : Hawk: The Blockchain Model of Cryptography and Privacy-Preserving Smart Contracts

Source : https://eprint.iacr.org/2015/675.pdf

Extract from Abstract

Emerging smart contract systems over decentralized cryptocurrencies  allow  mutually  distrustful  parties  to  transact safely  without  trusted  third  parties.  In  the  event  of  contractual  breaches  or  aborts,  the  decentralized  blockchain  ensures that honest parties obtain commensurate compensation. Existing systems,  however,  lack  transactional  privacy.  All  transactions, including   flow   of   money   between   pseudonyms   and   amount transacted,  are  exposed  on  the  blockchain.We present Hawk , a decentralized smart contract system that does  not  store  financial  transactions  in  the  clear  on  the  blockchain, thus retaining transactional privacy from the public’s view.A Hawk programmer  can  write  a  private  smart  contract  in  an intuitive manner without having to implement cryptography, and our  compiler  automatically  generates  an  efficient  cryptographic protocol where contractual parties interact with the blockchain, using  cryptographic  primitives  such  as  zero-knowledge  proofs. To   formally   define   and   reason   about   the   security   of   our protocols,  we  are  the  first  to  formalize  the  blockchain  model of cryptography. The formal modeling is of independent interest. We advocate the community to adopt such a formal model when designing  applications  atop  decentralized  blockchains.

Author Details


Ahmed Kosba, Andrew Miller at University of Maryland and Cornell University
{akosba, amiller}@cs.umd.edu, {rs2358, zw385}@cornell.edu, cpap@umd.edu

Ouroboros: A Provably Secure Proof-of-Stake Blockchain Protocol

Download here : Ouroboros: A Provably Secure Proof-of-Stake Blockchain Protocol

Source : https://eprint.iacr.org/2016/889.pdf

Extract from Abstract

We  present  “Ouroboros”,  the  first  blockchain  protocol  based  on proof  of  stake with  rigorous  security  guarantees.   We  establish  security  properties  for  the  protocol  comparable  to those achieved by the bitcoin blockchain protocol.  As the protocol provides a “proof of stake” blockchain discipline, it offers qualitative efficiency advantages over blockchains based on proof of physical resources (e.g., proof of work).  We also present a novel reward mechanism for incentivizing Proof of Stake protocols and we prove that, given this mechanism, honest behavior is an approximate Nash equilibrium, thus neutralizing attacks such as selfish mining.  We also present initial evidence of the practicality of our protocol in real world settings by providing experimental results on transaction confirmation and processing.

Author Details

Aggelos Kiayias at university of Edinburgh and IOHK,akiayias@inf.ed.ac.uk

Alexander Russell ,University of Connecticut,acr@cse.uconn.ed

USER PRIVACY IN THE PUBLIC BITCOIN BLOCKCHAIN

Download here : User Privacy in the Public Bitcoin Blockchain

Source : http://www.dtic.upf.edu/~jbarcelo/papers/20140704_User_Privacy_in_the_Public_Bitcoin_Blockchain/paper.pdf
vide JOURNAL OF LATEX CLASS FILES, VOL. 6, NO. 1, JANUARY 2007

Extract from Abstract

Bitcoin is a peer-to-peer electronic cash system that maintains a public ledger with all transactions. The public availability of this information has implications for the privacy of the users. The public ledger consists of transactions that transfer funds from a set of inputs to a set of outputs. Both inputs and outputs are linked to Bitcoin addresses. In principle, the addresses are pseudonymous. In practice, it is sometimes possible to link Bitcoin addresses to real identities with the consequent privacy leaks. The possibilities of linking addresses to owners are multiplied when addresses are reused to receive funds multiple times. The reuse of addresses also multiplies the amount of private information that is leaked when an address is linked to a real identity. In this work we describe privacy-leaking effects of address reuse and gather statistics of address reuse in the Bitcoin network. We also describe collaborative (CoinJoin) transactions that prevent the privacy attacks that have been published in the literature. Then we analyze the Blockchain to find transactions that could potentially be CoinJoin transactions.

Author Details

Jaume Barcelo available at http://jaume.barcelo.cc/

BITCOIN ECOLOGY: QUANTIFYING AND MODELLING THE LONG-TERM DYNAMICS OF THE CRYPTOCURRENCY MARKET

Download here : Bitcoin ecology: Quantifying and modelling the long-term dynamics of the cryptocurrency market

Source : https://arxiv.org/pdf/1705.05334.pdf

Extract from Abstract

The cryptocurrency market has reached a record of $91 billion market capitalization in May 2017,after months of steady growth.  Despite its increasing relevance in the financial world,  however,  a comprehensive analysis of the whole system is still lacking, as most studies have focused exclusively on the behavior of one (Bitcoin) or few cryptocurrencies.  Here, we consider the history of the entire market and analyze the behavior of 1,469 cryptocurrencies introduced since April 2013.  We reveal that, while new cryptocurrencies appear and disappear continuously and their market capitalization is  increasing exponentially,  several  statistical properties of  the  market  have been  stable for  years.These include the number of active cryptocurrencies, the market share distribution and the turnover of cryptocurrencies.  Adopting an ecological perspective, we show that the so-called neutral model of evolution is able to reproduce a number of key empirical observations, despite its simplicity and the assumption of no selective advantage of one cryptocurrency over another.  Our results shed light on the properties of the cryptocurrency market and establish a first formal link between ecological modeling and the study of this growing system.  We anticipate they will spark further research in this direction.

Author Details

Abeer ElBahrawy & Laura Alessandretti at Department of Mathematics - City, University of London - Northampton Square, London EC1V 0HB, UK

Email at Andrea.Baronchelli.1@city.ac.uk

THE ENVIRONMENT NEEDS CRYPTOGOVERNANCE by GUILLAUME CHAPRON

Download here : The environment needs cryptogovernance by Guillaume Chapron

Source : https://www.nature.com/polopoly_fs/1.22023!/menu/main/topColumns/topLeftColumn/pdf/545403a.pdf

Extract from Abstract

The blockchain technology that underpins cryptographic currencies can support sustainability by building trust and avoiding corruption, explains the author Guillaume Chapron along with technical challenges that come up expected.

Author Details

Guillaume Chapron  is associate professor in ecology at the Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences, Riddarhyttan, Sweden; and senior research associate at the Wildlife Conservation Research Unit, Recanati-Kaplan Centre, Department of Zoology, University of Oxford, Tubney, UK. 

e-mail: guillaume.chapron@slu.se

BLOCKCHAIN BASED TRUST & AUTHENTICATION FOR DECENTRALIZED SENSOR NETWORKS

Download here : Blockchain based trust & authentication for decentralized sensor networks

Source : https://arxiv.org/pdf/1706.01730.pdf

Extract from Abstract

Sensor networks and Wireless Sensor Networks (WSN) are key components for the development of the Internet of Things. These networks are subject of two kinds of constraints. Adaptability by the mean of mutability and evolutivity, and constrained node resources such as energy consumption, computational complexity or memory usage. In this context, none of the existing protocols and models allows reliable peer authentication and trust level management. In the field of virtual economic transactions, Bitcoin has proposed a new decentralized and evolutive way to model and acknowledge trust and data validity in a peer network by the mean of the blockchain. We propose a new security model and its protocol based on the blockchain technology to ensure validity and integrity of cryptographic authentication data and associate peer trust level, from the beginning to the end of the sensor network lifetime.

Author Details

Axel Moinet, Benoit Darties, and Jean-Luc Baril
axel.moinet@u-bourgogne.fr

BEYOND BITCOIN: ISSUES IN REGULATING BLOCKCHAIN TRANSACTIONS

Download here : BEYOND BITCOIN:  ISSUES IN REGULATING BLOCKCHAIN  TRANSACTIONS

Source : http://scholarship.law.duke.edu/cgi/viewcontent.cgi?article=3827&context=dlj

Extract from Abstract

The  buzz  surrounding  Bitcoin  has  reached  a  fever  pitch.  Yet  in  academic  legal  discussions,  disproportionate  emphasis  is  placed  on  bitcoins  (that  is,  virtual  currency),  and  little  mention  is  made  of  blockchain   technology ,the   true innovation   behind   the   Bitcoin   protocol. Simply, blockchain technology solves an elusive networking problem  by  enabling  “trustless” transactions:  value  exchanges  over  computer  networks  that  can  be  verified,  monitored,  and  enforced  without  central institutions  (for  example,  banks).  This  has  broad  implications for how we transact over electronic networks.  This   Note   integrates   current   research   from   leading   computer   scientists   and   cryptographers   to   elevate   the   legal  community’s   understanding  of blockchain  technology  and,  ultimately,  to  inform  policymakers  and  practitioners  as  they  consider  different regulatory  schemes. An examination of the economic properties of a blockchain-based currency suggests the technology’s true value lies in its potential to   facilitate   more   efficient   digital-asset   transfers.   For   example,   applications  of  special  interest  to  the  legal  community  include  more  efficient  document  and  authorship  verification,  title  transfers,  and  contract enforcement. Though a regulatory patchwork around virtual currencies  has  begun  to  form,  its  careful  analysis  reveals  much  uncertainty with respect to these alternative applications.

Author Details

TREVOR I.KIVIAT

Published in 2015

QUANTUM SECURED BLOCKCHAIN

Download here : Quantum Secured Blockchain

Source : https://arxiv.org/pdf/1705.09258.pdf

Extract from Abstract 

Blockchain is a distributed database which is cryptographically protected against malicious modifications. While promising for a wide range of applications, current blockchain platforms rely on digital signatures, which are vulnerable to attacks by means of quantum computers. The same, albeit to a lesser extent, applies to cryptographic hash functions that are used in preparing new blocks, so parties with access to quantum computation would have unfair advantage in procuring mining rewards. Here we propose a possible solution to the quantum-era blockchain challenge and report an experimental realization of a quantum-safe blockchain platform that utilizes quantum key distribution across an urban fiber network for information-theoretically secure authentication. These results address important questions about realizability and scalability of quantum-safe blockchains for commercial and governmental applications.

Author Details

E.O. Kiktenko and N.O. Pozhar at  Russian Quantum Center, Skolkovo, Moscow 143025

A.S. Trushechkin at Steklov Mathematical Institute of Russian Academy of Sciences, Moscow 119991

Published May 2017

IMPROVING DATA TRANSPARENCY IN CLINICAL TRIALS USING BLOCKCHAIN SMART CONTRACTS

Download here : Improving data transparency in clinical trials using blockchain smart contracts

Source : https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5357027/pdf/f1000research-5-10518.pdf

Extract from Abstract

The scientific credibility of findings from clinical trials can be undermined by a range of problems including missing data, endpoint switching, data dredging, and selective publication. Together, these issues have contributed to systematically distorted perceptions regarding the benefits and risks of treatments. While these issues have been well documented and widely discussed within the profession, legislative intervention has seen limited success. Recently, a method was described for using a blockchain to prove the existence of documents describing pre-specified endpoints in clinical trials. Here, we extend the idea by using smart contracts - code, and data, that resides at a specific address in a blockchain, and whose execution is cryptographically validated by the network - to demonstrate how trust in clinical trials can be enforced and data manipulation eliminated. We show that blockchain smart contracts provide a novel technological solution to the data manipulation problem, by acting as trusted administrators and providing an immutable record of trial history.

Author Details :

Timothy Nugent,Corporate Research and Development, Thomson Reuters, London, UK,tim.nugent@thomsonreuters.com

David Upton and Mihai Cimpoesu,Applied Innovation, Thomson Reuters, London, UK

BLOCKCHAIN-ORIENTED SOFTWARE ENGINEERING: CHALLENGES AND NEW DIRECTIONS

Download here : Blockchain-oriented Software Engineering: Challenges and New Directions

Source : https://arxiv.org/pdf/1702.05146.pdf

Extract from Abstract of this paper

The Blockchain technology is reshaping finance, economy, money to the extent that its disruptive power is compared to that of the Internet and the Web in their early days. As a result, all the software development revolving around the Blockchain technology is growing at a staggering rate. In this paper, we acknowledge the need for software engineers to devise specialized tools and techniques for blockchain-oriented software development. From current challenges concerning the definition of new professional roles, demanding testing activities and novel tools for software architecture, we take a step forward by proposing new directions on the basis of a curate corpus of blockchain-oriented software repositories, detected by exploiting the information enclosed in the 2016 Moody's Blockchain Report and the market capitalization of cryptocurrencies. Ensuring effective testing activities, enhancing collaboration in large teams, and facilitating the development of smart contracts all appear as key factors in the future of blockchain-oriented software development.

A KNOWLEDGE-BASED ANALYSIS OF THE BLOCKCHAIN PROTOCOL

Download here : A Knowledge-Based Analysis of the Blockchain Protocol

Source : https://arxiv.org/pdf/1707.08751.pdf

Extract from Abstract of this paper :

At the heart of the Bitcoin is a blockchain protocol, a protocol for achieving consensus on a public ledger that records bitcoin transactions.  To the extent that a blockchain protocol is used for applications such as contract signing and making certain transactions (such as house sales) public,  we need to understand what guarantees the protocol gives us in terms of agents’ knowledge.  Here, we provide a complete characterization of agent’s knowledge when running a blockchain protocol using a variant of common knowledge that takes into account the fact that agents can enter and leave the system, it is not known which agents are in fact following the protocol (some agents may want to deviate if they can gain by doing so), and the fact that the guarantees provided by blockchain protocols are probabilistic.  We then consider some scenarios involving contracts and show that this level of knowledge suffices for some scenarios, but not others.

Authors detail :

Joseph Y. Halpern
Cornell University
Ithaca, NY 14853, USA
halpern@cs.cornell.edu

Rafael Pass
Cornell University
Ithaca, NY 14853, USA
rafael@cs.cornell.edu

WHERE IS CURRENT RESEARCH ON BLOCKCHAIN TECHNOLOGY?—A SYSTEMATIC REVIEW

Download here : Where Is Current Research on Blockchain Technology? A Systematic Review

Source :  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5047482/

Extract from Abstract

Blockchain is a decentralized transaction and data management technology developed first for Bitcoin cryptocurrency. In this research, we have conducted a systematic mapping study with the goal of collecting all relevant research on Blockchain technology. Our objective is to understand the current research topics, challenges and future directions regarding Blockchain technology from the technical perspective. We have extracted 41 primary papers from scientific databases. The results show that focus in over 80% of the papers is on Bitcoin system and less than 20% deals with other Blockchain applications including e.g. smart contracts and licensing. The majority of research is focusing on revealing and improving limitations of Blockchain from privacy and security perspectives, but many of the proposed solutions lack concrete evaluation on their effectiveness. Many other Blockchain scalability related challenges including throughput and latency have been left unstudied. On the basis of this study, recommendations on future research directions are provided for researchers.

Author Details : sujinchoi@sogang.ac.kr

Jesse Yli-Huumo,Dept of Innovation and Software ,Lappeenranta University of Technology,Finland

Deokyoon Ko,Dept of Computer Science & Engineering,Sogang University,Seoul,South Korea 

Published in Oct 2016

BigchainDB: A SCALABLE BLOCKCHAIN DATABASE

Download here : BigchainDB: A Scalable Blockchain Database by Trent McConaghy

Source : https://www.bigchaindb.com/whitepaper/bigchaindb-whitepaper.pdf

Extract from Abstract of this paper :

This paper describes BigchainDB that fills a gap in the decentralization ecosystem: a decentralized database, at scale. It points to performance of 1 million writes per second throughput, storing petabytes of data, and sub-second latency. The BigchainDB design starts with a distributed database (DB), and through a set of innovations adds blockchain characteristics: decentralized control, immutability, and creation & movement of digital assets. BigchainDB inherits characteristics of modern distributed databases: linear scaling in throughput and capacity with the number of nodes, a fullfeatured NoSQL query language, efficient querying, and permissioning. Being built on an existing distributed DB, it also inherits enterprise-hardened code for most of its codebase. Scalable capacity means that legally binding contracts and certificates may be stored directly on the blockchain database. The permissioning system enables configurations ranging from private enterprise blockchain databases to open, public blockchain databases. BigchainDB is complementary to decentralized processing platforms like Ethereum, and decentralized file systems like InterPlanetary File System (IPFS). This paper describes technology perspectives that led to the BigchainDB design: traditional blockchains, distributed databases, and a case study of the domain name system (DNS). We introduce a concept called blockchain pipelining, which is key to scalability when adding blockchain-like characteristics to the distributed DB.

Author Details :

Trent McConaghy, Rodolphe Marques, Andreas M¨uller, Dimitri De Jonghe, T. Troy McConaghy, Greg McMullen, Ryan Henderson, Sylvain Bellemare, and Alberto Granzotto June 8, 2016 ascribe GmbH, Berlin, Germany

BLOCKCHAIN: THE HYPE, THE OPPORTUNITY AND WHAT YOU SHOULD DO ? BY ANGUS CHAMPION DE CRESPIGNY, ERNST & YOUNG LLP

Download here : Blockchain: the hype, the opportunity and what you should do ? By Angus Champion de

Source : https://goo.gl/7Ls9Hg

In Brief about this paper :

There has been plenty of noise, no doubt, but deep down there is substance. Blockchains (both public ones and those requiring permissions) carry great promise — databases are ubiquitous in every industry, and distributed consensus across an open network or a group of organizations is a valuable proposition and will force existing business models to evolve,creating entirely new business models in the process. And while in hindsight such developments seem to happen overnight,they take time, usually several years, to develop and mature.As with any new technology, there are risks,both technical and operational, associated with adoption, and organizations are right to consider these during their evaluations.This paper builds upon such threats and pro-active measures as may be desired to put the Cons at rest.

ENABLING BLOCKCHAIN INNOVATIONS WITH PEGGED SIDECHAINS

Download here : Enabling Blockchain Innovations with Pegged Sidechains

Source: https://www.blockstream.com/sidechains.pdf

Extract from Abstract of this Paper :

Since the introduction of Bitcoin in 2009, and the multiple computer science and electronic cash innovations it brought, there has been great interest in the potential of decentralised cryptocurrencies. At the same time, implementation changes to the consensus critical parts of Bitcoin must necessarily be handled very conservatively. As a result, Bitcoin has greater difficulty than other Internet protocols in adapting to new demands and accommodating new innovation.We propose a new technology, pegged sidechains, which enables bitcoins and other ledger assets to be transferred between multiple blockchains. This gives users access to new and innovative cryptocurrency systems using the assets they already own. By reusing Bitcoin’s currency, these systems can more easily interoperate with each other and with Bitcoin, avoiding the liquidity shortages and market fluctuations associated with new currencies. Since sidechains are separate systems, technical and economic innovation is not hindered. Despite bidirectional transferability between Bitcoin and pegged sidechains, they are isolated: in the case of a cryptographic break (or malicious design) in a sidechain, the damage is entirely confined to the sidechain itself. This paper lays out pegged sidechains, their implementation requirements, and the work needed to fully benefit from the future of interconnected blockchains.

Authors : 

Adam Back, Matt Corallo, Luke Dashjr, Mark Friedenbach, Gregory Maxwell, Andrew Miller, Andrew Poelstra, Jorge Timón, and Pieter Wuille

BLOCKCHAIN TECHNOLOGY: PRINCIPLES AND APPLICATIONS BY MARC PILKINGTON

Download here : Blockchain Technology: Principles and Applications by Marc Pilkington

Marc Pilkington is Associate Professor of economics at the University of Burgundy, France.

This paper expounds the main principles behind blockchain technology and some of its cutting-edge applications. It first presents the core concepts of the blockchain. Secondly, discusses a definition put forward by Vitalik Buterin; then sketch out the shift toward hybrid solutions, and sum up the main features of decentralized public ledger platforms. Thirdly, show why the blockchain is a disruptive and foundational technology, but expose the potential risks and drawbacks of public distributed ledgers that account for the shift toward hybrid solutions. Finally, presents a non-exhaustive list of important applications, bearing in mind the most recent developments.

Source : https://goo.gl/kSQeyv

ROADMAP FOR BLOCKCHAIN STANDARDS REPORT – MARCH 2017

 Download here : Roadmap for Blockchain Standards Report – March 2017

The emergence of new and exciting applications of blockchain and distributed ledger technologies (DLTs) present far-reaching opportunities for Australia and its international partners. Having first developed as a core component of the decentralized digital currency Bitcoin, Blockchain is now considered a  transformational technology with broader applications. Blockchain has the potential to support efficient and secure real time transactions across a large number of sectors. From enabling efficient and accurate financial services to providing visibility along the supply chain, and from streamlining government services to delivering confidence in identity accuracy to consumers,blockchain and DLTs have the capacity to revolutionize the way we do business.

The Roadmap for Blockchain Standards was developed through a collaborative and inclusive process involving the participation and contributions of key stakeholders representing government, industry, research and consumer organisations.The stakeholders collectively assessed the priority standards-related matters for Blockchain and the use-cases that Australia should be promoting internationally through ISO/TC 307.

About Standards Australia 

Founded in 1922, Standards Australia is an independent, not-for-profit organisation,recognised by the Commonwealth Government as the peak non-government Standards development body in Australia. It is charged by the Commonwealth Government to meet Australia’s need for contemporary, internationally-aligned Standards and related services. The work of Standards Australia enhances the nation’s economic efficiency,international competitiveness and contributes to community demand for a safe and sustainable environment.Source : www.standards.org.au

BITCOIN: AN INNOVATIVE ALTERNATIVE DIGITAL CURRENCY BY REUBEN GRINBERG

Download here : Bitcoin: An Innovative Alternative Digital Currency

Bitcoin is novel digital currency that has the potential to be a significant player in the micropayment and virtual world commerce markets. It is also a great alternative currency for gold bugs who prefer to hold currencies fully backed by commodities. Furthermore,because it is anonymous and decentralized, and therefore difficult to shut down, it may allow organisations hated by governments whether these are morally commendable or detestable organisations—to be funded without risk of monetary seizure or sanctions on financial contributors.

While the history of currencies such as the Iraqi Swiss Dinar that had no backing by either commodities or government entities indicates that Bitcoin may succeed, potential users and investors should be aware of the many risks inherent in using such a young technology. Most importantly, Bitcoin currently operates in a legal grey area. The federal government’s supposed monopoly on issuing currency is somewhat narrow and statutes that impose that monopoly do not seem to apply to Bitcoin due to its digital nature. However, a bitcoin may be a “security” within the meaning of the federal securities laws, subjecting bitcoins to a vast regime of regulations, including general antifraud rules. Although the best argument is that a bitcoin is not a security, Bitcoin’s proponents will have to await an SEC or court interpretation for certainty. Furthermore, other legal issues that have not been analyzed in this Article are probably significant, including tax evasion, banking without a charter, state escheat statutes, and money laundering.

BITCOIN-NG: A SCALABLE BLOCKCHAIN PROTOCOL

Download here : Bitcoin-NG: A Scalable Blockchain Protocol

This paper is included in the Proceedings of the 13th USENIX Symposium on Networked Systems Design and Implementation (NSDI ’16).March 16–18, 2016 • Santa Clara, CA, USA

ISBN 978-1-931971-29-4

Open access to the Proceedings of the 13th USENIX Symposium on Networked Systems Design and Implementation (NSDI ’16) is sponsored by USENIX.

Extract from Abstract of this paper 

Cryptocurrencies, based on and led by Bitcoin, have shown promise as infrastructure for pseudonymous on-line payments, cheap remittance, trustless digital as-set exchange, and smart contracts. However, Bitcoin-derived blockchain protocols have inherent scalability limits that trade off between throughput and latency,which withhold the realization of this potential.This paper presents Bitcoin-NG (Next Generation), a new blockchain protocol designed to scale. Bitcoin-NG is a Byzantine fault tolerant blockchain protocol that is robust to extreme churn and shares the same trust model as Bitcoin.In addition to Bitcoin-NG, we introduce several novel metrics of interest in quantifying the security and efficiency of Bitcoin-like blockchain protocols. We implement Bitcoin-NG and perform large-scale experiments at 15% the size of the operational Bitcoin system, using unchanged clients of both protocols. These experiments demonstrate that Bitcoin-NG scales optimally,with bandwidth limited only by the capacity of the individual nodes and latency limited only by the propagation time of the network.

AN ANALYSIS OF ANONYMITY IN THE BITCOIN SYSTEM

Download here : An Analysis of Anonymity in the Bitcoin System

Paper Presented in 2011 IEEE International Conference on Privacy, Security, Risk, and Trust, and IEEE International Conference on Social Computing

Extract from Abstract of this paper

Anonymity in Bitcoin, a peer-to-peer electronic currency system, is a complicated issue. Within the system,users are identified by public-keys only. An attacker wishing to de-anonymize its users will attempt to construct the one-to-many mapping between users and public-keys and associate information external to the system with the users. Bitcoin frustrates this attack by storing the mapping of a user to his or her public-keys on that user’s node only and by allowing each user to generate as many public-keys as required. In this paper we consider the topological structure of two networks derived from Bitcoin’s public transaction history. We show that the two networks have a non-trivial topological structure,provide complementary views of the Bitcoin system and have implications for anonymity. We combine these structures with external information and techniques such as context discovery and flow analysis to investigate an alleged theft of Bitcoins, which, at the time of the theft, had a market value of approximately half a million U.S. dollars.

Authors Details

Fergal Reid
Clique Research Cluster
University College Dublin, Ireland
fergal.reid@gmail.com

Martin Harrigan
Clique Research Cluster
University College Dublin, Ireland
martin.harrigan@ucd.ie

A FISTFUL OF BITCOINS: CHARACTERIZING PAYMENTS AMONG MEN WITH NO NAMES

Download here : A Fistful of Bitcoins: Characterizing Payments Among Men with No Names

Extract from Abstract of this paper: 

Bitcoin is a purely online virtual currency, unbacked by either physical commodities or sovereign obligation; instead, it relies on a combination of cryptographic protection and a peer-to-peer protocol for witnessing settlements. Consequently, Bitcoin has the unintuitive property that while the ownership of money is implicitly anonymous, its flow is globally visible. In this paper we explore this unique characteristic further, using heuristic clustering to group Bitcoin wallets based on evidence of shared authority, and then using reidentification attacks (i.e., empirical purchasing of goods and services) to classify the operators of those clusters. From this analysis, we characterize longitudinal changes in the Bitcoin market,the stresses these changes are placing on the system, and the challenges for those seeking to use Bitcoin for criminal or fraudulent purposes at scale.

Author Details :

Sarah Meiklejohn, Marjori Pomarole ,Grant Jordan ,Kirill Levchenko, Damon McCoy, Geoffrey M. Voelker and Stefan Savage

University of California, San Diego George Mason University

BITCOIN: A PEER-TO-PEER ELECTRONIC CASH SYSTEM : ORIGINAL PAPER BY SATOSHI NAKAMOTO

Download here : Bitcoin: A Peer-to-Peer Electronic Cash System : ORIGINAL PAPER

EXTRACT from ABSTRACT of this paper

A purely peer-to-peer version of electronic cash would allow online payments to be sent directly from one party to another without going through a financial institution. Digital signatures provide part of the solution, but the main benefits are lost if a trusted third party is still required to prevent double-spending.We propose a solution to the double-spending problem using a peer-to-peer network.The network timestamps transactions by hashing them into an ongoing chain of hash-based proof-of-work, forming a record that cannot be changed without redoing the proof-of-work. The longest chain not only serves as proof of the sequence of events witnessed, but proof that it came from the largest pool of CPU power. As long as a majority of CPU power is controlled by nodes that are not cooperating to attack the network, they'll generate the longest chain and outpace attackers. The network itself requires minimal structure. Messages are broadcast on a best effort basis, and nodes can leave and rejoin the network at will, accepting the longest proof-of-work chain as proof of what happened while they were gone.

Author Details :

Satoshi Nakamoto
satoshin@gmx.com
www.bitcoin.org