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