Abstract—In this paper, we identify a new form of attack, called the Balance attack, against proof-of-work blockchain systems. The novelty of this attack consists of delaying network communications between multiple subgroups of nodes with balanced mining power. Our theoretical analysis captures the precise tradeoff between the network delay and the mining power of the attacker needed to double spend in Ethereum with high probability. We quantify our probabilistic analysis with statistics taken from the R3 consortium, and show that a single machine needs 20 minutes to attack the consortium. Finally, we run an Ethereum private chain in a distributed system with similar settings as R3 to demonstrate the feasibility of the approach, and discuss the application of the Balance attack to Bitcoin. Our results clearly confirm that main proof-of-work blockchain protocols can be badly suited for consortium blockchains.
We’re pleased to announce the first public release of our Imandra-based formal model of the Ethereum Virtual Machine (EVM). We’ve made the model open source under the Apache 2.0 license. This model gives Imandra a formal semantics of Ethereum bytecode, so that Imandra can be used to reason about the possible behaviours of compiled Ethereum smart contracts. It’s the first public entry in our community models repository. Read more at http://www.github.com/AestheticIntegration/contracts/. We hope this model will be useful to the community, and that it will be improved (see the ongoing TODO in the github repository), ported and built upon by many. Happy verifying!
Preamble IOTA was initiated with a very clear and focused vision of enabling the paradigm shift of the Internet of Things, Industry 4.0 and a trustless ‘On Demand Economy’ through establishing a de facto standardized ‘Ledger of Everything’. Since the very first lines of code was typed in middle of 2015 the project has come a long way, but in the big picture of this great journey IOTA development has only barely begun. This article unveils and outlines the IOTA Foundation’s public roadmap towards realizing this vision. This roadmap will be continuously updated in accordance with development progress and addition of new items. There are a lot of other stuff in the pipeline which will be added when ready to be unveiled.
AT&T, IBM, Nokia, Palo Alto Networks, Symantec, and Trustonic formed an IoT Cybersecurity Alliance earlier this week, seeking to research security challenges and influence security standards and policies. Whenever a conversation about security surfaces, the idea of applying blockchain inevitably appears. Now, you’ve probably heard of Bitcoin and blockchain, but if you are like most people, you might not really understand how it works.
Blockchain will do for transactions what the internet did for information. This collection features a selection of stories about the subject. DeepMind’s New Blockchain-Style System Will Track Health-Care Records Congress Takes Blockchain 101 The World’s Largest Shipping Company Trials Blockchain to Track Cargo Why Bitcoin’s $1,000 Value Doesn’t Matter Web Pioneer Tries to Incubate a Second Digital Revolution
IBM unveiled its "Blockchain as a Service" today, which is based on the open source Hyperledger Fabric, version 1.0 from The Linux Foundation. IBM..
The latest project from Google's AI lab depends less on trendy ideas than an apparent desire to solve a real problem in the real world.
When Bitcoin was created in 2009 it sparked a social and technological movement and has since sent ripples across the financial industry.
There is a tremendous amount of activity focused on blockchain. Several blockchain-related organiza...
The convergence of blockchain and the Internet of Things will happen. While IBM and others have solutions, challenges remain.
Learn how to use the IBM #Blockchain platform for an #IoT application in a multi-partner environment. #IBMcloud
By logging how every piece of patient data is used, the company hopes to leave behind an indelible audit trail.
In today’s digital age, there are many people on the quest towards the Internet of things (IoT). Now, a new micro-transaction crypto-token called IOTA looks to facilitate the architecture involved wit
What links flowers, mandarin oranges, and pineapples? They’re all neatly recorded on Maersk’s new digital shipping ledger.
innogy Innovation Hub explores IOTA for Machine Economy
IOTA is a revolutionary distributed ledger for the Internet of Things. It enables machine-to-machine payments as well as data transfers without any fees.