Abstract Recent work has demonstrated significant anonymity vulnerabilities in Bitcoin's networking stack. In particular, the current mechanism for broadcasting Bitcoin transactions allows third-party observers to link transactions to the IP addresses that originated them. This lays the groundwork for low-cost, large-scale deanonymization attacks. In this work, we present Dandelion++, a first-principles defense against large-scale deanonymization attacks with near-optimal information-theoretic guarantees. Dandelion++ builds upon a recent proposal called Dandelion that exhibited similar goals. However, in this paper, we highlight simplifying assumptions made in Dandelion, and show how they can lead to serious deanonymization attacks when violated. In contrast, Dandelion++ defends against stronger adversaries that are allowed to disobey protocol. Dandelion++ is lightweight, scalable, and completely interoperable with the existing Bitcoin network. 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Abstract We present and validate a novel mathematical model of the blockchain mining process and use it to conduct an economic evaluation of the double-spend attack, which is fundamental to all blockchain systems. Our analysis focuses on the value of transactions that can be secured under a conventional double-spend attack, both with and without a concurrent eclipse attack. Our model quantifies the importance of several factors that determine the attack's success, including confirmation depth, attacker mining power, and any confirmation deadline set by the merchant. In general, the security of a transaction against a double-spend attack increases roughly logarithmically with the depth of the block, made easier by the increasing sum of coin turned-over (between individuals) in the blocks, but more difficult by the increasing proof of work required. In recent blockchain data, we observed a median block turnover value of 6 BTC. Based on this value, a merchant requiring a single confirmation is protected against only attackers that can increase the current mining power by 1% or less. However, similar analysis shows that a merchant that requires a much longer 72 confirmations (~12 hours) will eliminate all potential profit for any double-spend attacker adding mining power less than 40% of the current mining power. References
Bonneau, J., Miller, A., Clark, J., Narayanan, A., Kroll, J., Felten, E.: Sok: Research perspectives and challenges for bitcoin and cryptocurrencies. In: IEEE S&P. pp. 104–121 (May 2015), http://doi.org/10.1109/SP.2015.14
Meiklejohn, S., Pomarole, M., Jordan, G., Levchenko, K., McCoy, D., Voelker, G., Savage, S.: A Fistful of Bitcoins: Characterizing Payments Among Men with No Names. In: Proc. ACM IMC. pp. 127–140 (2013), http://doi.acm.org/10.1145/2504730.2504747
Sasson, E.B., Chiesa, A., Garman, C., Green, M., Miers, I., Tromer, E., Virza, M.: Zerocash: Decentralized anonymous payments from bitcoin. In: IEEE S&P. pp. 459–474 (2014), http://dx.doi.org/10.1109/SP.2014.36
Why large chunks of early mined coins never been used?
Here is an interesting read, Analysis of the Bitcoin Transaction Graph http://eprint.iacr.org/2012/584.pdf It was ran in May 2012, so it is a bit old (and I would love to see a newer analysis), but what I am going to address this will still do. According to the analysis, by May 2012 there were about 9 million BTCs created, but only about 2 millions were in circulation, being transfered for whatever reasons. The authors also mention that most of the earliest created coins never moved. Now let's speculate what could be the reasons for this, and if we find the correct answer, we might find the answer why Bitcoins were created in the first place. By earliest coins I mean the first 3-4 million mined. Reasons for coins never moved after creation:
They were lost before they could be used. This is a fairly simple, neutral and probably true reason. We could argue just what % is lost, specially in the early days when the coins were useless (thus people who got them simply forgot about them and the coins never recovered), but this number could be significant. I read somewhere that the size of the newer coins lost is in the hundred thousands. So we could assume that as much as half million early coins could have been lost.
The early adopters trusted so much that Bitcoin's value is going to take off, that simply they are still holding them, instead of circulating them. This could also be possible, but I have a few problems with this explanation. First, it is incredibly hard to time any market. So if early adopters are still holding, they have to be very astute investors and they were able to hold through a pretty decent runup to $30 and the following crash last year, without the temptation and fear of cashing out. We also have to assume that in the time between now and the creation (2-3 years) they didn't need most of the money. Most investors would start to cash out at least partially, once the value takes off. But anyway,if the whole point of making Bitcoin was to create a new and decentralized currency, why are these people hording? Why didn't they spread the then worthless coins (keeping maybe a little for themselves, just in case) so more would be in circulation and it could be used as currency??? The whole altruistic, I create a virtual money for all to use and never to inflate thingy just sound fake, once you know the fact of early coins never been used... Again, it is hard to put a % on it, but I am sure at least a few of the earliest miners have been holding until this day. When you are planning to sell for 1000s, little price changes like 50 to 150 is just noise.
What if Satoshi and his team were really US government employees and Bitcoin is a test, an experience by the NSA (or your favorite government agency)? Then the earliest millions of coins were mined on government computers and thus they would be considered government property. When Bitcoin was worthless, who cared? But when it started to take off in value, they couldn't just sell government property for personal gain, right? I guess they could donate it and give it away, but not cashing it out... IAlso they might keep them for future action, if let's say they eventually want to crash the market and the idea.
Some combination of the above reasons... I would like to hear more possible reasons, but I think these 3 could be the main ones. I personally don't buy the altruistic/hobby creator explanation and tend to think that Bitcoin was either made for personal gains or as a government experience....
Why do I believe it was BCN destiny to be born in 2012?
Why do I believe it was BCN destiny to be born in 2012? Just look at this and see yourself: 1983 - Blind signatures were invented by David Chaum link 1997 - HashCash (proof of work system) was invented by Adam Back link 2001 - Ring signatures were invented by Ron Rivest, Adi Shamir, and Yael Tauman link 2003 - Mart n Abadi, Michael Burrows, and Ted Wobber presented "Moderately hard, memory-bound functions"link 2004 - Patrick P. Tsang and Victor K. Wei presented their paper "Short linkable ring signatures for e-voting, e-cash and attestation" link 2005 - Matthew Franklin and Haibin Zhang with "Unique Group Signatures" study link 2005 - Exponential memory-bound functions for proof of work protocols by Fabien Coelho link +2006 - "Traceable Ring Signature" by Fujisaki and Suzuki link 2008 - Bitcoin whitepaper by Satoshi Nakamoto link 2009 - Stronger key derivation via sequential memory-hard functions by Colin Percival link 2009 - First Bitcoin block was generated 2010 -2012 - Bitcoin Anonymity Problem Discussions link 2011 - An Analysis of Anonymity in the Bitcoin System, Fergal Reid and Martin Harrigwere link 5/15/2012 - Dorit Ron and Adi Shamir made Quantitative Analysis of the Full Bitcoin Transaction Graph link 6/8/2012 - Bytecoin Wiki started link 6/30/2012 - Bytecoin launch announcement link- first news 7/4/2012 - First BCN block was generated link 8/6/2012 - Destination Address Anonymization in Bitcoin (one-time addresses in BCN) link 10/19/2012 - Evaluating User Privacy in Bitcoin by Elli Androulaki, Ghassan O. Karame, Marc Roeschlin, Tobias Scherer, Srdjan Capkun. link 12/12/2012 -CryptoNote whitepaper v 1.0 link 12/13/2012 - Analysis of hashrate-based double-spending, Meni Rosenfeld link 10/17/2013 - CryptoNote whitepaper v 2.0 link Here we see how the technology logically came to the advent of cryptocurrencies with ring signature and memory-bound function PoW implementation. Soon after Bitcoin's release the community started to raise concerns about its anonymity with multiple solutions and propositions. High concentration of theoretical papers on these topics in 2009-2011 most probably spurred the brightest minds to make attempts of practical e-cash with ring signatures realization. Therefore, BCN couldn't but appear in 2012. Based on https://bitcointalk.org/index.php?topic=512747.msg7093354#msg7093354
We should probably not think of the Bitcoin money supply (Price x bitcoin in circulation) as market cap. Better to compare like with like. We can compare with other currencies. We can do this in terms of the M1 money supply (which equates to cash, checking accounts and other "near money" vehicles). One lightly used currency, the Icelandic Kroner, has M1 of about $3.3 bn at the moment. The population of Iceland is 327,000. Right now (June 12th) we could say that Bitcoin has an M1 of roughly $10 bn - three times as much, implying (very roughly) a Bitcoin population of about 1 million citizens. Bitcoin M1 is also a little less than one three hundredth of the MI money supply of the US with its 300+ millions of citizens - which also indicates a Bitcoin population of about 1 million citizens. Bitcoin is (clearly) also a vehicle for speculation, so this is only a rough equation and does not properly indicate how much Bitcoin usage reflects payments. However the Bitcoin transaction graph has a clear upward trend indicating a growing population of bitcoin users. This should lead us to expect that if the Bitcoin user population increase by a factor of 10 then so will the price - although it may do more than that because the speculators would probably go wild and create a temporary bubble in the currency's value. The Bitcoin population will definitely increase by such a factor because it is a viral currency. It is impossible (for me at least) to know how fast that population will grow and what its practical upper limit is.
Let's contact Ron and Shamir asking them to help us fully map MtGox presence on the blockchain.
Some time ago there was a really good paper studying the blockchain. In this they studied the whole blockchain and connected the accounts that sent money together as coming from the same wallet. Quantitative Analysis of the Full Bitcoin Transaction Graph from Dorit Ron and Adi Shamir By doing this they could identify several whales. Now, I think that with the situation with MtGox we should ask the help from those two researchers, and fully map MtGox activity. If we all share the entry point and the exit address in which we sent money and received money from MtGox it should be quite easy to just map the whole animal out. This would be divided, I suppose, in entry address, exit address, inside address never used but only rarely to store coins, in between address. And then maybe we can start to see exactly from which address some bitcoins have been siphoned out. It's just a simple unidirectional graph. I don't know how many nodes will it have, but probably we should be able to even draw it. Any comments before contacting them?
P2Pcash means no middlemen that you need to have faith in. I only need to trust the network. Because I know at least 1 miner will eventually mine my transaction and spread to the whole network. Because of a near complete graph in bitcoin network.
Graph: Mempool Transaction Count - The number of transactions waiting to be confirmed. Backlogs at an all-time high, users experiencing delays, unable to transact, miners losing fees. Bitcoin network congested and unreliable due to Core/Blockstream's never-ending obstructionism, censorship and lies.
These graphs show that fees for inclusion in 2nd block just shot up 10x from 50 to 500 satoshis/kB, and mempool size just shot up from <5 MB to 30 MB. Would you feel safe sending a transaction into the network now? Can Bitcoin rally if the blocksize remains artificially limited by Blockstream/Core?
http://statoshi.info/dashboard/db/fee-estimates To select a longer time period, zoom out on the graph by clicking on the word "6 hours ago" to the right of the words "Zoom Out" - which will reveal a drop-down menu. https://tradeblock.com/bitcoin To see the increase in the Mempool Size (from less than 5 MB, to 30 MB), go to the graph on the graph on the lower right called "Recent Mempool", and use the two menus to select "7 Days" and "Size". How can Bitcoin continue to rally, if the network is becoming backlogged due to unnecessary congestion?
Charts providing a snapshot of the Bitcoin Cash (BCH) ecosystem Bitcoin Charts & Graphs Bitcoin Evolution auszahlung. Die letzte Halbierung erfolgte im Juli 2020, die nächste im Jahr 2020. Schließlich können sie die lokalen Behörden nicht so gut kontaktieren und behaupten, dass die Gelder, die sie für den Verkauf illegaler Drogen erhalten haben, gestohlen wurden. Die crypto community ist normalerweise ziemlich schnell dabei, das Thema Betrug zu ... The median time for a transaction with miner fees to be included in a mined block and added to the public ledger. Average Confirmation Time . The average time for a transaction with miner fees to be included in a mined block and added to the public ledger. Mining Information. Total Hash Rate (TH/s) The estimated number of terahashes per second the bitcoin network is performing in the last 24 ... This analysis demonstrates the power of data mining techniques in analyzing large payment systems, and especially publicly available transaction graphs of the type provided by the Bitcoin scheme. View The number of daily confirmed transactions highlights the value of the Bitcoin network as a way to securely transfer funds without a third part. Notes. Transactions are accounted for only once they are included in a block. During times of peak mempool congestion, transactions with lower fees are likely to be confirmed after a few hours or even days in rare cases. While this graph is a suitable ...
CLICK HERE: http://top-deal.pro/cryptoenter?a=ndc According to Blockchain.info, over the past three days, fees on the Bitcoin network have risen by 191% from... In this quick video, we do our best to explain the mechanics of a single Bitcoin transaction in 5 minutes or less. We explain things like addresses, wallet a... Analyzing Blockchain and Bitcoin Transaction Data as Graph - Duration: 51:44. Oracle Developers 2,513 views. 51:44. Don't Make The Same MISTAKES As Me! Crypto Trading Tips For BEGINNERS! The biggest bitcoin transaction in history, how much was a transaction fee and how it affected the bitcoin price. About Bitwala Candles Bitwala Candles is an... Blockchain technology and Bitcoin will potentially revolutionize business transactions. Blockchain offers a robust, decentralized platform for privacy and tr...