Posts tagged bitcoin

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.
My quick reaction to the latest salvo of shots fired in the war between Core developers and miners.
BitFury has been mining smallest-transactions-first. We argue why this is bad for Bitcoin.

The Greening of Blockchains

Blockchains are beginning to turn green. This post describes some of the IC3 research in this direction.
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 is an evaluation platform which provides a principled way of evaluating different blockchain proposals.
As regulators take a closer interest in cryptocurrencies, IC3 faculty weigh in on if and how they should be regulated.
We unveil a new technology for secure, high throughput, low latency Bitcoin transactions using secure hardware, on the current Bitcoin network.
We introduce the first workable sharding solution for blockchains.
We introduce a novel consensus mechanism that greatly improves security, throughput, and transaction confirmation latency of blockchain-based cryptocurrencies.
The Bitfinex attack, and similar heists from Bitcoin exchanges, are preventable with a small extension to Bitcoin.
I point out some of the pitfalls I see my colleagues fall into as Craig Wright's Satoshi saga unfolds.
Craig Wright has made yet another claim to be Satoshi Nakamoto. This post describes what it takes to make a credible claim.
There was a bitcoin transaction carrying a $137K fee. This posts examines why transactions might carry such large fees, and rules out some explanations.
There was a series of heists at ShapeShift, followed by an offered explanation. That offered explanation has more holes in it than Swiss cheese.
My take on how software gets bloated, using a cautionary tale from the telephony world, with applications to Bitcoin.
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 have the potential to stop Bitcoin thefts from Bitcoin clients. This post answers some frequently asked questions about them.
We have come up with a simple and elegant technique for implementing hack-proof Bitcoin vaults, to deter Bitcoin thefts.
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.
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.
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.
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.
Some people say that "if Bitcoin relies on altruism, then it has already failed." Bitcoin relies heavily on altruism, and it has not failed.
I try to lay to rest a bad way to account for Bitcoin network costs and a flawed argument for exorbitantly high fees.
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.
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 modest suggestion on how to proceed with the block size debate, wherein we suggest explicitly defining the criteria for evaluating block size increase proposals.
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.
We introduce a new technique for increasing the throughput and reducing the latency, at the same time, of blockchain-based protocols
The recent Bitcoin blocksize debate demonstrates the need for a robust governance structure.
There is a new craze in the Bitcoin world, and it's not good for Bitcoin.
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 remains dismal, as evidenced by the lengths Bitcoin users must go through to secure their digital assets.
This is a quick blog post to dispel a common Bitcoin misconception/myth involving voting power.
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.
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.
A Bitcoin mining pool, called GHash and operated by an anonymous entity called, just reached 51% of total network mining power today. Bitcoin is no longer decentralized. This note describes what we should do about it.
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.
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.
A quick summary of the red flags that preceded the demise of Neo & Bee, the latest Bitcoin startup from Cyprus.
A story that explains every public utterance by a man who wrote his own SSH server in PHP.
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 when someone in the network is engaged in selfish mining
BTC Guild released a number of blocks in quick succession, making some people worry that they are selfish mining. We discuss the evidence.
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.
New measurements show that successful selfish mining attacks are quite feasible.

Cash-Boycotts: How to Use Bitcoins for Social Change

Bitcoin's unique features allow it to be used to for social causes. A cash boycott is one such way to affect social change.
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.
There is now a visual simulator for our selfish mining attack.
There have been some early, and often misplaced, responses to the vulnerabilities we discovered in the Bitcoin system. This post addresses them.
Came across a video describing how Bitcoin works for a non-techie audience.
The claim that our results were previously known to the Bitcoin community is specious.
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.
Policy regarding comments.
If the health of your cryptocurrency requires Gordon Gekko to make sacrifices, it is doomed.
Some clarifications and answers to frequently asked questions about the selfish mining attack on Bitcoin.
We discovered an attack against the Bitcoin mining protocol that can have a significant impact on the Bitcoin community.
Introducing Virtual Notary, a free, novel service for attesting to online facts.