Posts tagged bitcoin

The Old Fee Market is Broken, Long Live the New Fee Market

bitcoin ethereum January 22, 2019 at 11:31 AM Soumya Basu, David Easley, Maureen O'Hara, and Emin Gün Sirer

We describe why the fee market is fundamentally broken and propose an alternative fee mechanism that fixes the issues with the current fee market.

Paralysis Proofs: How to Prevent Your Bitcoin From Vanishing

ethereum bitcoin sgx paralysis proofs January 18, 2018 at 09:30 AM Fan Zhang, Phil Daian, Iddo Bentov, and Ari Juels

Suppose that N players share cryptocurrency using an M-of-N multisig scheme. If N-M+1 players disappear, the remaining ones have a problem: They've permanently lost their funds. In this blog, we propose a solution to this critical problem using the power of the trusted hardware.

Decentralization in Bitcoin and Ethereum

bitcoin ethereum January 15, 2018 at 07:37 AM Adem Efe Gencer, Soumya Basu, Ittay Eyal, Robbert van Renesse, and Emin Gün Sirer

We have been examining the state of the Bitcoin and Ethereum networks over time. In a recent study, we examine the level of decentralization in these two networks, with some interesting takeaways for the future.

How Not To Run A Blockchain Lottery

lottery bitcoin blockchain December 25, 2017 at 08:05 AM Emin Gün Sirer

Devising a lottery based off of a blockchain is a lot harder than it seems. Also, this is a parable for the Bitcoin blockchain debate.

Who Has Your Back in Crypto?

bitcoin ecosystem August 26, 2017 at 01:55 PM Emin Gün Sirer

Between miners, businesses and developers, people think that the developers have their best interests at heart. I discuss why this is a fallacy.

Bitcoin's Impending Accounting Disaster

bitcoin bitfinex bcc fork July 31, 2017 at 04:20 AM Emin Gün Sirer

Shenanigans at Bitfinex are poised to mess up their accounting, confuse the price of BCC, and potentially bankrupt the already-bankrupt exchange.

Atomically Trading with Roger: Gambling on the success of a hardfork

bitcoin loaded roger atomic trade gamble unlimited July 11, 2017 at 07:20 PM Patrick McCorry, Ethan Heilman, and Andrew Miller

A new atomic trade protocol to allow two parties to publicly pledge support for different forks in the event a blockchain splits into two.

Hijacking Bitcoin: Routing Attacks on Cryptocurrencies

routing bgp bitcoin May 01, 2017 at 10:48 AM Maria Apostolaki, Aviv Zohar, and Laurent Vanbever

Cryptocurrencies are vulnerable to attacks targeting the network routing layer. In this guest post, Apostolaki, Zohar and Vanbever show that BGP attacks are back, and this time, they have a high value target.

A Thinking Person's Guide to the Latest Bitcoin Drama

bitcoin segwit April 05, 2017 at 08:48 PM Emin Gün Sirer

My quick reaction to the latest salvo of shots fired in the war between Core developers and miners.

BitFury's Smallest-First Mining Is Bad For Bitcoin

bitcoin mining February 27, 2017 at 10:33 AM Emin Gün Sirer

BitFury has been mining smallest-transactions-first. We argue why this is bad for Bitcoin.

The Greening of Blockchains

bitcoin green February 23, 2017 at 12:23 PM Phil Daian and Ari Juels

Blockchains are beginning to turn green. This post describes some of the IC3 research in this direction.

State of the Bitcoin Network

bitcoin measurement February 15, 2017 at 10:18 AM Adem Efe Gencer and Emin Gün Sirer

We characterize the state of the Bitcoin network as of this year, and discover that it has improved by 70% in terms of bandwidth compared to last year alone.

Miniature World: Measuring and Evaluating Blockchains

blockchain evaluation bitcoin emulation testbed February 10, 2017 at 10:10 AM Adem Efe Gencer and Emin Gün Sirer

Miniature world is an evaluation platform which provides a principled way of evaluating different blockchain proposals.

Will Cryptocurrencies Be Centrally Controlled? What Would Hamilton Do?

bitcoin sec ic3 January 09, 2017 at 08:42 AM Jim Ballingall

As regulators take a closer interest in cryptocurrencies, IC3 faculty weigh in on if and how they should be regulated.

Scaling Bitcoin with Secure Hardware

bitcoin lightning payment channels December 22, 2016 at 09:10 AM Joshua Lind, Ittay Eyal, Peter Pietzuch, and Emin Gün Sirer

We unveil a new technology for secure, high throughput, low latency Bitcoin transactions using secure hardware, on the current Bitcoin network.

Service-Oriented Sharding with Aspen

bitcoin aspen bitcoin-ng service-oriented sharding December 06, 2016 at 02:35 PM Adem Efe Gencer and Emin Gün Sirer

We introduce the first workable sharding solution for blockchains.

ByzCoin: Securely Scaling Blockchains

bitcoin byzcoin blocksize August 04, 2016 at 12:57 PM Philipp Jovanovic

We introduce a novel consensus mechanism that greatly improves security, throughput, and transaction confirmation latency of blockchain-based cryptocurrencies.

How the Bitfinex Heist Could Have Been Avoided

bitcoin vaults security August 03, 2016 at 07:20 AM Emin Gün Sirer

The Bitfinex attack, and similar heists from Bitcoin exchanges, are preventable with a small extension to Bitcoin.

Logical Fallacies in the Hunt for Satoshi

bitcoin satoshi May 04, 2016 at 09:40 AM Emin Gün Sirer

I point out some of the pitfalls I see my colleagues fall into as Craig Wright's Satoshi saga unfolds.

Extraordinary Satoshi Claims

bitcoin satoshi May 02, 2016 at 04:00 PM Emin Gün Sirer

Craig Wright has made yet another claim to be Satoshi Nakamoto. This post describes what it takes to make a credible claim.

Bitcoin's $137,000 Jackpot

bitcoin fees tumblers money-laundering April 29, 2016 at 08:48 AM Christian Decker and Emin Gün Sirer

There was a bitcoin transaction carrying a $137K fee. This posts examines why transactions might carry such large fees, and rules out some explanations.

The ShapeShift Hack: Simply Incredible

shapeshift security bitcoin ethereum April 25, 2016 at 08:48 AM Emin Gün Sirer

There was a series of heists at ShapeShift, followed by an offered explanation. That offered explanation has more holes in it than Swiss cheese.

How Software Gets Bloated: From Telephony to Bitcoin

bloat software bitcoin segwit April 05, 2016 at 10:55 AM Emin Gün Sirer

My take on how software gets bloated, using a cautionary tale from the telephony world, with applications to Bitcoin.

Bitcoin Guarantees Strong, not Eventual, Consistency

bitcoin consistency cap March 01, 2016 at 12:15 PM Emin Gün Sirer

Some people claim that Bitcoin is eventually consistent. They are wrong. This post tries to dispel the myth and explain the right way to evaluate the consistency guarantees of distributed systems.

Bitcoin Vaults: How to Put an End to Bitcoin Theft

bitcoin security vaults February 29, 2016 at 01:15 PM Malte Möser, Ittay Eyal, and Emin Gün Sirer

Bitcoin vaults have the potential to stop Bitcoin thefts from Bitcoin clients. This post answers some frequently asked questions about them.

How to Implement Secure Bitcoin Vaults

bitcoin security vaults February 26, 2016 at 09:00 AM Malte Möser, Ittay Eyal, and Emin Gün Sirer

We have come up with a simple and elegant technique for implementing hack-proof Bitcoin vaults, to deter Bitcoin thefts.

Bitcoin's Value Derives from Users, not Miners

bitcoin voting January 05, 2016 at 10:40 AM Emin Gün Sirer

Evidently, a requirement for becoming a CEO at a Bitcoin exchange or payments company is to believe that your company has no power and works entirely at the discretion of the miners. I try once again to correct this myth.

Time for Bitcoin Users to Reclaim Their Voice

bitcoin voting blocksize January 01, 2016 at 03:40 PM Emin Gün Sirer

I make the case that Bitcoin users have just as much of a say, or more, than all the miners combined. They wield this power through exchanges, and the exchanges need to live up to their responsibilities.

A Technique to Unite Bitcoin Factions

bitcoin blocksize December 30, 2015 at 09:30 AM Emin Gün Sirer and Ittay Eyal

In an effort to bring the fruitless Bitcoin block size debate to a close, this post outlines Bitcoin-Unified, an approach to accommodate both small and large blocks.

No Such Thing as Developing a Fee Market

bitcoin blocksize December 23, 2015 at 11:00 AM Emin Gün Sirer

The phrase "developing the fee market" gets used a lot in Bitcoin circles. This post makes the case that this is a thinly veiled euphemism for jacking up the fees.

Bitcoin Runs On Altruism

bitcoin altruism game theory December 22, 2015 at 01:30 PM Emin Gün Sirer

Some people say that "if Bitcoin relies on altruism, then it has already failed." Bitcoin relies heavily on altruism, and it has not failed.

A Bad Argument for High Bitcoin Fees

bitcoin blocksize December 16, 2015 at 03:30 PM Emin Gün Sirer

I try to lay to rest a bad way to account for Bitcoin network costs and a flawed argument for exorbitantly high fees.

How To Spot Satoshi

bitcoin satoshi not satoshi December 10, 2015 at 11:43 AM Emin Gün Sirer

The press is doing a fresh manhunt for Satoshi again. This post focuses on one of the effective techniques to recognize Satoshi if he were to walk among us.

How to Compress Bitcoin

bitcoin blocksize December 02, 2015 at 02:13 PM Emin Gün Sirer

Peter Tschipper has been looking into compressing the Bitcoin messages on the wire using generic compressors. In this post, I discuss why generic compressors will not work well with Bitcoin, make the case for a custom compressor, and suggest that we run a community challenge to develop the best compressor.

A Suggestion For How to Proceed with the Bitcoin Block Size Debate

bitcoin blocksize bitcoin-ng November 13, 2015 at 12:08 PM Emin Gün Sirer

A modest suggestion on how to proceed with the block size debate, wherein we suggest explicitly defining the criteria for evaluating block size increase proposals.

Bitcoin-NG: Unshackling Blockchains

bitcoin blocksize bitcoin-ng November 09, 2015 at 12:08 PM Ittay Eyal and Emin Gün Sirer

We review some of the feedback we received on Bitcoin-NG and discuss why every new permission-less ledger would be better off with NG compared to the alternatives.

Bitcoin-NG: A Secure, Faster, Better Blockchain

bitcoin blocksize bitcoin-ng October 14, 2015 at 01:05 PM Ittay Eyal and Emin Gün Sirer

We introduce a new technique for increasing the throughput and reducing the latency, at the same time, of blockchain-based protocols

A Coin Needs a Board

bitcoin blocksize governance August 17, 2015 at 02:35 PM Ittay Eyal

The recent Bitcoin blocksize debate demonstrates the need for a robust governance structure.

ChangeTip Must Die

changetip bitcoin privacy micropayments December 17, 2014 at 10:40 AM Emin Gün Sirer

There is a new craze in the Bitcoin world, and it's not good for Bitcoin.

The Miner's Dilemma

bitcoin mining pools security 51% December 03, 2014 at 12:15 PM Ittay Eyal

In a new analysis of Bitcoin mining, Ittay Eyal shows that the equilibrium between miners is unstable, and identifies a stable equilibrium that might, as a side effect, reduce the size of open, public mining pools.

State of Computer Security, 2014 Edition

bitcoin security November 30, 2014 at 09:17 AM Emin Gün Sirer

State of computer security remains dismal, as evidenced by the lengths Bitcoin users must go through to secure their digital assets.

Bitcoin and Voting Power

bitcoin security ghash 51% voting June 19, 2014 at 05:56 PM Emin Gün Sirer

This is a quick blog post to dispel a common Bitcoin misconception/myth involving voting power.

How to Disincentivize Large Bitcoin Mining Pools

bitcoin security mining pools 51% June 18, 2014 at 02:03 PM Ittay Eyal and Emin Gün Sirer

We outline a small change to the Bitcoin mining protocol that rules out big, public mining pools. It preserves the current investment in Bitcoin by both existing users and by existing miners. It presents a fix to GHash's recent 51% excursion.

How A Mining Monopoly Can Attack Bitcoin

bitcoin security mining pools 51% June 16, 2014 at 02:35 PM Ittay Eyal and Emin Gün Sirer

There seems to be a lot of confusion over the kinds of attacks that a Bitcoin mining monopoly can engage in. We clarify the space of attacks available to a Bitcoin mining monopoly.

It's Time For a Hard Bitcoin Fork

bitcoin security ghash 51% June 13, 2014 at 02:05 PM Ittay Eyal and Emin Gün Sirer

A Bitcoin mining pool, called GHash and operated by an anonymous entity called CEX.io, just reached 51% of total network mining power today. Bitcoin is no longer decentralized. This note describes what we should do about it.

Willy and Markus Do Not Prove Market Manipulation

bitcoin mt. gox May 27, 2014 at 12:10 PM Emin Gün Sirer

Recent leaks of Mt. Gox trading history has caused people to claim that massive market manipulation was taking place. I argue that there is no evidence for this.

NoSQL Meets Bitcoin and Brings Down Two Exchanges: The Story of Flexcoin and Poloniex

nosql bitcoin mongo broken April 06, 2014 at 12:15 PM Emin Gün Sirer

The real story of how weak NoSQL systems allowed users to make money out of the thin air and brought down two Bitcoin exchanges, one permanently.

Five Red Flags that Preceded Neo & Bee's Collapse

bitcoin neo&bee broken April 05, 2014 at 05:00 PM Emin Gün Sirer

A quick summary of the red flags that preceded the demise of Neo & Bee, the latest Bitcoin startup from Cyprus.

A Just-So Story About What May Have Happened At Mt.Gox

bitcoin mt. gox March 22, 2014 at 09:08 AM Emin Gün Sirer

A story that explains every public utterance by a man who wrote his own SSH server in PHP.

What Did Not Happen At Mt. Gox

bitcoin mt. gox March 01, 2014 at 09:35 AM Emin Gün Sirer

There are lots of theories about what may have happened at Mt. Gox. This post examines what may not have happened, and how to avoid that which did happen.

How to Detect Selfish Miners

bitcoin selfish-mining January 15, 2014 at 12:25 PM Ittay Eyal and Emin Gün Sirer

How to detect when someone in the network is engaged in selfish mining

BTC Guild Gets Lucky

bitcoin security selfish-mining January 01, 2014 at 11:13 PM Ittay Eyal and Emin Gün Sirer

BTC Guild released a number of blocks in quick succession, making some people worry that they are selfish mining. We discuss the evidence.

Claiming Bitcoin's Bug Bounty

leveldb bitcoin November 27, 2013 at 04:53 PM Robert Escriva

Bitcoin was having problems with LevelDB. We identified and fixed the bug. In this article, we'll talk a little about LevelDB, Bitcoin, and our fix.

Bitcoin Block Propagation Speeds

bitcoin security selfish-mining November 25, 2013 at 03:15 PM Ittay Eyal and Emin Gün Sirer

New measurements show that successful selfish mining attacks are quite feasible.

Cash-Boycotts: How to Use Bitcoins for Social Change

bitcoin cash-boycott November 21, 2013 at 07:53 AM Giray Pultar, Selcuk Pultar, and Emin Gün Sirer

Bitcoin's unique features allow it to be used to for social causes. A cash boycott is one such way to affect social change.

Why Da Man Loves Bitcoin

bitcoin security anonymity November 19, 2013 at 08:41 AM Emin Gün Sirer

The Feds testified exuberantly in favor of Bitcoins yesterday, driving the BTC price through the roof to $900 USD. This is my quick reaction to what happened and what we should do about it.

Selfish Mining Simulator

bitcoin security selfish-mining November 17, 2013 at 02:40 PM Ittay Eyal and Emin Gün Sirer

There is now a visual simulator for our selfish mining attack.

Response to Feedback on Selfish Mining

bitcoin security selfish-mining November 14, 2013 at 09:45 AM Ittay Eyal and Emin Gün Sirer

There have been some early, and often misplaced, responses to the vulnerabilities we discovered in the Bitcoin system. This post addresses them.

Clearest Description of Bitcoin To Date

bitcoin silly November 10, 2013 at 10:36 AM Ittay Eyal and Emin Gün Sirer

Came across a video describing how Bitcoin works for a non-techie audience.

No, You Di'n't!

bitcoin security selfish-mining November 09, 2013 at 11:55 AM Ittay Eyal and Emin Gün Sirer

The claim that our results were previously known to the Bitcoin community is specious.

Response to Fairweather Mining

bitcoin security broken selfish-mining November 08, 2013 at 11:21 AM Ittay Eyal and Emin Gün Sirer

Fairweather mining has been suggested to argue that selfish mining would be a short-lived strategy, but fairweather mining analysis is flawed because it does not take proofs of work into account.