Questions tagged [attack]

Relates to attempts to harm the Bitcoin network. In cryptography, an attack is a method/technique to break the code. Bitcoin also has to deal with other types of attack, such as double spends and denial of service.

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1answer
1k views

What does a double spend look like?

What does a double spend look like? Can anyone link to an example on blockchain.info? Will invalid half of the double spend simply remain at 0-confirmations, or might it ever reach 1 or 2? Will the ...
8
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2answers
2k views

What is the story behind the "Linode problem"?

What is the story behind the "Linode problem"? How did the service become compromised and what has exactly happened because of it?
2
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1answer
511 views

What is the story behind MyBitcoin?

The name of MyBitcoin eWallet comes up quite often here and there. What is the story behind it and the attack on it they claimed occurred?
3
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1answer
131 views

Is an attack on a local bitcoind via an img or embedded flash viable?

In this thread on the Bitcoin forums it was suggested that a local attack on bitcoind might be possible through malformed img tags or (more likely in my opinion) through embedded flash. This also ...
16
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3answers
4k views

What can be done about the no-transaction block relayer (currently 71.123.170.150)?

An unknown major solo miner (currently IP 71.123.170.150), most likely a botnet, is relaying blocks with zero transactions. Two weeks ago this miner constituted ~15% of the network, now it constitutes ...
10
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2answers
2k views

Which blocks get to be checkpoints?

Which blocks get to be checkpoints, and why is one block chosen to be a checkpoint, rather than another block? And where can I find a list of checkpoint blocks?
2
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2answers
750 views

How would one inject a blockchain fork to the Bitcoin network?

For theoretical purposes, how would one inject a blockchain fork in to the Bitcoin network? For example, lets say we have a small chain of blocks prepared in a program that is not a standard client / ...
5
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2answers
152 views

Current block vs whole block chain attack

If an evil computer network wanted to attack Bitcoin, would they need to have more computing power than the present Bitcoin network and then attack a current block, or would they need even more to go ...
17
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4answers
6k views

What are the risks of using Strongcoin.com as an online wallet?

Strongcoin claims it is "The Safest way to store your Bitcoins. The only Bitcoin e-wallet service that's not vulnerable to security breaches. Your Bitcoin keys are encrypted in the browser." ...
11
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3answers
824 views

Flaw in Bitcoin protocol regarding incentives to share transactions

Once the 50BTC per block rewards have halved many times and the transaction fees start to become the primary reward for miners, it sound like there is incentive for miners to not pass on transactions ...
8
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4answers
586 views

Would any of the current botnets be able to launch and sustain a 51% attack?

The "owners" of botnets probably runs them as businesses, meaning that they will always seek profit-optimization. Do you believe that it is a matter of time before they will seek to launch and sustain ...
5
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2answers
681 views

How to perform a double spend attack in websites that accept transactions with 0 confirmations?

To perform a Finney attack or a 51% attack I need to have lots of computational power, but in this case (a website that accepts transactions with 0 confirmations) it seems to me that I only need to ...
7
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4answers
243 views

Do no-fee transaction represent a greater risk if the product is delivered instantly?

Let's say I want to accept payments instantly on a site for digital downloads. So I publish an address and wait for the unconfirmed transaction, I see the transaction and release the digital download....
7
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1answer
486 views

What is the maximum number of signature check operations a transaction script can request?

As transaction size, the number of signature checks per transaction can affect client performance and the inclusion of many O_CHECKSIG opcodes could be used as a tool for denial-of-service attacks. I ...

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