9

Are there any others that are particularly effective? Yes, if you know what wallet was used and if its transactions have distinguishing features. For example, multisig wallets usually use p2sh change, but the recipient rarely uses p2sh, which allows to determine the correct change output with high probability. Data-Driven De-Anonymization in Bitcoin ...


7

You're missing the main point: when a selfish miner finds a new block, he keeps it private, does not broadcast it to the network, and starts mining on top of that privately. The rest of the network is still mining on a block that was actually already found, but not broadcast. When the rest of the network finally finds this block, the selfish miner ...


6

Biggest problem facing spaceborne bitcoin is communications latency. Consider possible Mars colony. Light speed imposes delay, 4 to 24 minutes. Bad enough this is. If miners on both Earth and Mars, each comes up with new block, possibly extends blockchain twice more, before signal from other crosses distance. Means very long transaction confirmation ...


5

To answer your direct question, transactions will be delayed by the round-trip time light takes to get to the nearest mining community. With low-earth orbit, this really shouldn't make much of a difference. That said, the deeper problem once space travel is wide-spread is that the current protocol is inherently space-time centralized. This is because the ...


5

What use is a transaction that is never relayed? None, unless it is generated by the same person who mines it into a block. But it is not the case that non-standard transactions are never relayed. There are nodes that relay non-standard transactions and miners who include them. How did the transaction make it into a block in the first place if it cannot ...


4

The report is not heavily disputed. In the hours following the paper's release, several developers are discussing solutions: http://www.mail-archive.com/bitcoin-development@lists.sourceforge.net/msg03128.html and http://bitcointalk.org/index.php?topic=324413.0 There has not been any evidence that such an attack is imminent or likely even. And remember,...


4

Hashcash is one of the many anti-spam techniques used today, which is essentially a proof-of-work system designed to limit not only email spam but also denial-of-service attacks. A similar proof-of-work methodology is being used in bitcoin for block generation. With an average of 150 billion e-mails sent out on a daily basis I cannot see how this could be ...


3

b-money proposes to pay for money minting by means of proof-of-work. The minted money then has the value of the expended computational power. For value transfers it either relied on a synchronous unjammable channel and arbitration, or on a set of trusted servers that had to be regularly audited by the other network participants. In other words, b-money used ...


3

I know of one researcher off hand who has worked in this area, Adam Hayes. You can find his papers on the subject at: http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2648366 http://www.economicpolicyresearch.org/econ/2015/NSSR_WP_052015.pdf You could also look around on http://arxiv.org/. Just searching for 'bitcoin price', I found: http://arxiv.org/...


3

Note that there is a new and better paper about this topic by Aviv Zohar et al. - http://arxiv.org/pdf/1507.06183v1.pdf. None of the solutions suggested have been implemented yet. The attack is significant enough that some solution will need to be found, but that's up to researchers, not developers.


3

I haven't read any papers trying to analyze the amount of unspent outputs. More often, people are interested in the distribution of address' balances. This could be interesting because it reflects how evenly distributed bitcoin is. I did find this article: http://www.coindesk.com/what-block-chain-analysis-tells-bitcoin/, which seems like it might be of ...


3

I think that http://bitcoinacademic.wordpress.com could be able to help. There is a wide collection of academic research in many fields. However, you are right, there are not that many peer reviewed journal articles out there, but I do think some of this research is valuable and provides interesting insights.


2

The interesting thing about that paper is that, if I understood correctly, it doesn't require pools to collude in order to attempt the "selfish miner" strategy - any pool with more than 25% of the total hash power could do it solo - right now there are pools which could do it. And with just slightly more than 33% of total hash power, they could make their ...


2

Bitcoin, as it works now should work fine in low-earth orbits. I'm pretty sure that anyone currently in space has sufficient internet access and computing resources to view the network, post transactions, and probably even mine. But that's boring... Beyond low-earth orbits, say more than 5 light-minutes* out, I wouldn't recommend mining. There is a limit to ...


2

Selfish mining is probably one of the most addressed issues that was theorized by a group at Cornell university. I find this interesting, because rather than being a technical issue such as transaction malleability, it is more of a conceptual issue with how Bitcoin and its consensus system works. That should get you started and give you some food for ...


2

Is the attack really practical? Eh... maybe. The whitepaper you linked makes two assumptions, and it's not clear how well those hold up in practice. It costs nothing (or close to nothing compared to mining pool revenue) to run a sybil attack. From the paper: Because selfish mining is reactive, and it springs into action only after the honest nodes ...


2

There are some excellent papers by Aviv Zohar (Red balloons, GHOST etc.) which at least touch on game theory. There's also a comprehensive list of papers at https://docs.google.com/spreadsheets/d/1VaWhbAj7hWNdiE73P-W-wrl5a0WNgzjofmZXe0Rh5sg/edit#gid=0, you can browse it to see if any could be relevant.


2

There is none that I'm aware of, but technically speaking, the blockchain and the transaction hash would suffice to find it. It might be nice to add the block height number as well. Something like: Tx 35779d11b2c5aedc1ada50aaa33aafb53ccc07dae71e6d18a35a0ccb872a0efa, Bitcoin Block 342508 Would work as a citation.


2

The balance is calculated from the UTXO set where unspent outputs belong to the address in question. Most block explorers will enable the transaction index, parse the historical and live data, and dump it into a database that runs on top of bitcoin to track additional statistics. As you can imagine this requires a lot more disk storage, but it makes things ...


2

Currently, it seems, most of Bitcoin-related published research are of technical and legal nature (according to Google Scholar, Mendeley, Bitcoin Wiki). While there is some economical analysis performed by community (wiki, this question), I haven't managed to find any papers in peer-reviewed journals. This discission on Quora explains some of possible ...


2

You could in theory build an ASIC to brute force private keys of any cryptographic scheme, like EC or RSA. But ASICs only give linear improvements. That means that they 'accelerate' some search only by a constant factor, like 2, 3 or 100. Even if your ASIC does something a million times faster than a normal CPU, it's still a linear improvement. If ...


2

I held a research period on bitcoin (thanks to this project I became fond of Bitcoin) with the release of the alpha software at December, I had to extract information for the construction of an information graph. I believe in my opinion that there are really many ways to index information but I believe that the fastest ones are to use the same technique that ...


1

You could have a look at this long list of Bitcoin's weaknesses. Since your question is aimed at blockchains in general, why not also take a look at Ethereum's list of problems.


1

I think it's scalability. The cost to generate a block is getting more and more expensive. Couple months ago, CryptoKitties caused Ethereum network congestion due to the surge of transactions. For real world application, I think blockchain must be able to handle high volume of transaction. This can be achieved by reducing the cost to generate a block. AFAIK, ...


1

Although the phenomenon of Induced Demand is critical to effort to scale Bitcoin, it has not often been cited in public discussion. I refer to the following article, from Wired magazine, that discusses the issue in layman's terms: https://www.wired.com/2014/06/wuwt-traffic-induced-demand/ If we make an analogy between an urban public road network and the ...


1

As far as I understand the diagram was produced for IEEE Spectrum. They have a Reprints & Permissions page that might help to get in touch with them on this matter.


1

Most Bitcoin thefts occurs due to user careless and ignorance, like not using two-factor authentication and sharing email and password across questionable websites. The risk of theft can be easily reduced by taking the basic security measurements which you should follow in any case when you are dealing with Internet. Here are some things you should include ...


1

There are some research papers out there, including about bitcoins economical viability. A wonderful (a pleasure for hours) and fairly complete list can be found on the wiki. A random chosen abstract: Bitcoin has emerged as a fascinating phenomenon of the financial markets. Without any central authority issuing the currency, it has been associated with ...


1

While I didn't see it addressed explicitly in the paper, the attack could be defeated by requiring a competing blockchain to have common ancestry in the proof-chain in order for it to be considered. Out of the proposed triplet account-tree, mini-blockchain, and proof-chain, the proof-chain has by far the least memory requirement with only 512 bit (64 byte) ...


1

Selfish mining is not related to the three factors you mentioned. The basic idea is that a miner can do one of two things: Shift her mining efforts on top of any new legitimate block she hears about and broadcast to the network any block she finds as soon as she finds it When she finds a block, instead of broadcasting it immediately, keep it to herself ...


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