Bitcoin: Can destroy China, the crypto currency number one? In the second part. In the first part we have considered the phenomenon of the empty blocks, the Chinese Miner mining. The consideration of the Papers by Kaiser et al. we will continue now and look at the hazards which have been identified by the authors of the Papers. For the classification we allow ourselves to be an important Framework of quality management for inspiration.
A column by Dr. Philipp Giese
In the first part of the consideration, if any, risk to Bitcoin from China, we have the blocks looked. Together with the Paper by Kaiser et al. we looked into the past and learned that from 2015 to 2016, higher than average number of empty blocks of Chinese miners were gemint. The reason for this is the Great Firewall of China, or that big data could be exchanged packages bad between Chinese Nodes, and the Rest of the world. The Bitcoin Protocol has been optimized, so that the mines of empty blocks should actually be useful.
With some concern, we had to see, however, that at least in the last days, the proportion of empty blocks was again very high. To give a lump sum of China, the debt would be unfair, because we were able to classify Antpool as the main responsible. We concluded, therefore, that the focus is on China alone, some narrow-minded, and that every single one of us should have, in accordance with the Motto of „Do Your Own Research“ the Bitcoin Blockchain with respect to any anomalies in the eye.
The main part of the Paper analyzes various attacks on the Bitcoin network and classifies them according to purpose, visibility, attack the target and prerequisites. As possible purpose the authors see as censorship, Deanonymization, destabilization of the consensus, and the interference of competing Miner.
censorship on the Blockchain – the role of The Miner
As a censorship-supporting attack vectors, one is the selective Forking or Feather Forking. In both cases, it is one of the miners outbound control. Selective Forking means that a minende entity, which holds about 51 percent of the Hashrate, integrated, specific transactions, their addresses are on a Blacklist, in blocks.
It is to call Feather Forking as a „weak variant“ of the selective Forking, must not be controlled 51 percent of the Hashrate. It can, however, lead to a risk if an attacker wants to dine his own Version of the Blockchain without the censoring transactions into the network. He succeeds often enough, it could cause other miners to join the censoring of consensus.
Both are variants of a 51-percent attacks, and quickly in the network would be visible. Nodes would see a disturbing correlation between Chain reorganizations and the Mining activity. Certain transactions would stay in the Mempool, so that the Nodes would notice that something is in the Bush.
an Eclipse attack could take control of a very powerful attacker, the Connections between miners and Nodes, respectively, of the Nodes to each other, so that the Nodes no censorship notice. A similar approach is the control of traffic on the Internet.
A look at the worldwide distribution of Full Nodes, but also shows what one can rely on the attacker for a global Power. Of the currently approximately 10,000 Nodes 24 percent in the Americas, 19 percent in Germany, and only seven percent in China. The remaining fifty per cent are distributed in 110 countries.
Deanonymization – hunting on the Blockchain
I find it interesting that the Paper Deanonymization devotes so much room. It is not known that Bitcoin is the most anonymous of all the block chains. Whom it comes to such systems, such as Monero. Here, the focus on China is also surprising. Because of the various Nations and authorities in the network to track the activity in the Bitcoin, is also known as suggestions for improvement, such as Taproot and Dandelion.
in any case, the authors see the clusters of Wallet addresses, or the Monitoring of the network by Association of the Wallet – with IP addresses as potential attack vectors. This work would not have to make a powerful attacker such as a government, but could require dealers and exchanges to the sharing of customer data. On the use of trackers, the attacker could also the anonymity of Bitcoin users is undermined. Finally, you could simply use the human factor and classic methods of denunciation.
destabilization of the Bitcoin consensus – is An attack on the Protocol
The Narrative Bitcoins the Immutabilität. A destruction of this would damage Bitcoin really. In order to make the Immutabilität in question needs to be asked of the Bitcoin consensus with regard to the order of the transactions in question. The classic Double-Spending attack, a Miner with 51 percent of the Hashrate has, would be such an attack on the Immutabilität.
Two different variants of this Double-Spending attack, the Race attack and the Finney attack, depending on whether the attacker wants to make one or more blocks back. Among such attacks, the Brute-Force attack in which the attacker’s own Blockchain mint.
A particularly common type of Double-Spending attack, the Balance-of-attack. Two different blocks are sent to different subsets of the Miner, resulting in confusion. The attacker could use its hash rate, which does not have to be the case, 51 percent, in the connector for the chosen subset, and so still „his“ Version of the Blockchain. Unlike the classic 51-percent attacks, one could not detect whether or not a centralized party organized the Chain Reorganizations.
A Goldfinger attack is a variant of the 51-percent-attack is ideologically motivated. The attacker is not looking for any financial Profit, but by questioning the Immutabilität the Bitcoin Ecosystem weaknesses.
Finally, call the Selfish Mining. A Miner keeps found blocks for himself, until the accumulated Proof-of-Work is at least as large as the actual Blockchain. The subsequent publication can lead to destructive Forks and the transcription of large parts of the Bitcoin history.
Up on the Balance attack all of these attacks require a very high Hashrate. This condition can be weakened in the case of parallel execution of an Eclipse attack something.
destabilization of the Miner-Community
the Above attacks focus on the User and the Ecosystem as a whole. With other Angriffsvektoren you can attack the other Miner. An entity with a large Hashrate would receive most of the Rewards. The Mining would be more profitable. Miner would then connect with your Hashrate, where appropriate, to the Mining Pool of the attacker.
in addition to the above Selfish Mining, the authors identify and hold the Back of the blocks as a possible attack vector. Miner on the side of the attacker would infiltrate a Mining Pool, and there, although partial Proofs of Work, but not the found blocks to the network to send. This would make the Pool self-starvation, so that other miners will leave that Pool. A repeated application could destroy the competing Pools. In addition to the back, an attacker could publish his blocks in such a way that it initiates a Fork to hold blocks up to Starve.
How to classify these attack vectors?
vectors as far as to the in the Paper described attack. What to make of this? We will use this classification, however, is similar to the FMEA principles.
FMEA stands for failure mode and effect analysis. In the context of quality management, it is used for, possible sources of error, assess whether your risk and to articulate on the Basis of measures. Each hazard is assigned a rating in respect of the risk and the importance of (B), the probability (A) and the detection probability (E).
it is Classically associated with the three sizes B, A, and E is a number between 1 and 10 and by multiplying the three another measure called the „risk priority number“ is formed. More and more Knowledgeable about go, however, to reduce the scales for B, A and E only to a few values such as „low“, „medium“ and „high“ and the risk priority number to an integer.
We will go this way, since the significance of a risk is always the most important one of all sizes. To get a crooked back due to a bad Desk chair, even if it occurs more frequent, less relevant than the power stroke to an open line, to put it figuratively. In addition, we will consider instead the probability of the occurrence of the requirements to be fulfilled by the attacker. Since no product is formed from the values, we can the importance, of assigning probability and the detection probability of occurrence of specific values.
A complete FMEA would blow up the framework, the authors discussed the attack can be estimated vectors according to:
The FMEA makes no dogmatic claim – neither on completeness nor on a hundred percent correctness. Just the reviews in terms of significance, likelihood of occurrence and the probability are reasonable, but subjective assessments. Should have something incorrect crept in, is, of course, constructive Feedback is welcome.
do Not panic, Bitcoin is evolving
So, objectively, the Paper reads in comparison to the articles in the digital forest of leaves, two things you can blame him for that: The focus on China is quite confusing. Probably, China has interest in control over Bitcoin, but similar allegations, you can make other States or powerful entities. Just about Deanonymization, it is surprising to corresponding measures as an attack on Bitcoin itself. The „Never-Ending-Story“ Silk Road demonstrates very well that Bitcoin can live without the guise of anonymity can be good, and that States other than China have an interest in a deanonymization.
Secondly, it is quite alarmist. „Bitcoin will destroy“ is a very hard formulation, which would deserve a more detailed specification. That such an attack can weaken the vectors and the possible global reach of the Internet to control Bitcoin and large problems, is obvious. However, this is not a Destroy. Similarly, the Paper overlooks the fact that these attack vectors are known. Measures in such cases are known.
Also, the developers are tinkering continues on the Bitcoin network. It is not a solidified ivory tower, whose gates are just waiting for a burglar. Between the attackers and the developers of a competition. The above analysis shows that the most critical attack vectors, mostly to be solved with the same measures. The Blockchain and the use of GATE-watching Services are two effective ways to be the aforementioned risks, Mr. Such attacks should be successful, can be considered further measures, such as switching to a new Proof of Work or the implementation of a new checkpoint. Although the complex solutions would be, but „“ would be destroyed Bitcoin for a long time.
Finally, no one is allowed to forget the world beyond Bitcoins. With a view to the great world of crypto currencies overall, it is definitely too early to see a death threat to Bitcoin and the entire cryptocurrency sector.