The technical side of Bitcoin
In recent months, the peer-to-pir Bitcoin currency has seriously increased in popularity, mainly due to press references and the involvement of a mass audience. At the same time, as far as I can tell, skepticism is widespread among experts, up to and including “Bitcoin is a scam” . In the past, I developed payment systems and P2P systems, and I had to work with cryptography. Therefore, I read the available sources and tried to consider the Bitcoin technology from a technical point of view, as carefully as possible. I offer you a brief Russian translation of the material .
So, it is stated that Bitcoin is (1) peer-to-peer (2) anonymous (3) secure digital currency. In my opinion, all three statements are controversial and can only be accepted if the definitions are somewhat broadened.
Bitcoin is not a peer-to-peer, because to perform operations, a participant needs information on all operations in the system. Accordingly, without having complete information on each transaction (in the world!), It is impossible to make transactions on your own. If the system serves any serious flow of transactions, it will inevitably split into "peers" (peers) and "commoners" (commoners).
Commoners will pay peers for the right to complete transactions, and peers will need to have non-trivial matfund funds to perform their functions.
With anonymity in Bitcoin, everything is also a bit vague. Yes, for each transaction, each participant creates a one-time wallet. However, in principle, complex transactions (involving several coins) potentially reveal one-time wallets belonging to the same holder. Also, given the ability to track all transactions, it is impossible to exclude the possibility of total surveillance of such a network. Such surveillance will be completely invisible to participants; in contrast to the classic special services, the spikes will not leave any papers or evidence.
')
With security, everything is also slightly doubtful. Cryptographic security is based on cost asymmetries: if I encrypt something with strong crypto, an attacker needs to burn two suns to blunt the cipher. Alas, only individual transactions are heavily encrypted in Bitcoin. The whole construction as a whole rests on very dubious bolts - proof-of-work chains. If an attacker has computing resources comparable to the network's power (peers), he can do various foci (see the original text ). The bad asymmetry is that the peers need to burn electricity around the clock to maintain the network. An attacker can mobilize their resources only for a short period. Another bad asymmetry: to try double-spending, the attacker can only offer a coin to several victims at the same time. Victims need to either be aware of all transactions (in the world), or wait from 10 minutes to 1 hour until the transaction is reliably postponed in the history of the "peers".
Thus, the main point of the Bitcoin program is to prevent double spending without attracting third parties, it does not hold water. Third parties (peers) will not care, but to what extent it is possible to avoid fraud in practice is not quite clear.
What also strikes the eye: with the exception of the “political” program and marketing packaging, it is unclear how Bitcoin is better than the modern European banking system. Moreover, it is much worse: in my Internet bank, zero commissions and instant payment within the country. In Bitcoin, commissions are inevitable, plus the operation takes 10 minutes.
The general conclusion: Bitcoin is a well-advertised project :)
So, it is stated that Bitcoin is (1) peer-to-peer (2) anonymous (3) secure digital currency. In my opinion, all three statements are controversial and can only be accepted if the definitions are somewhat broadened.
Bitcoin is not a peer-to-peer, because to perform operations, a participant needs information on all operations in the system. Accordingly, without having complete information on each transaction (in the world!), It is impossible to make transactions on your own. If the system serves any serious flow of transactions, it will inevitably split into "peers" (peers) and "commoners" (commoners).
Commoners will pay peers for the right to complete transactions, and peers will need to have non-trivial matfund funds to perform their functions.
With anonymity in Bitcoin, everything is also a bit vague. Yes, for each transaction, each participant creates a one-time wallet. However, in principle, complex transactions (involving several coins) potentially reveal one-time wallets belonging to the same holder. Also, given the ability to track all transactions, it is impossible to exclude the possibility of total surveillance of such a network. Such surveillance will be completely invisible to participants; in contrast to the classic special services, the spikes will not leave any papers or evidence.
')
With security, everything is also slightly doubtful. Cryptographic security is based on cost asymmetries: if I encrypt something with strong crypto, an attacker needs to burn two suns to blunt the cipher. Alas, only individual transactions are heavily encrypted in Bitcoin. The whole construction as a whole rests on very dubious bolts - proof-of-work chains. If an attacker has computing resources comparable to the network's power (peers), he can do various foci (see the original text ). The bad asymmetry is that the peers need to burn electricity around the clock to maintain the network. An attacker can mobilize their resources only for a short period. Another bad asymmetry: to try double-spending, the attacker can only offer a coin to several victims at the same time. Victims need to either be aware of all transactions (in the world), or wait from 10 minutes to 1 hour until the transaction is reliably postponed in the history of the "peers".
Thus, the main point of the Bitcoin program is to prevent double spending without attracting third parties, it does not hold water. Third parties (peers) will not care, but to what extent it is possible to avoid fraud in practice is not quite clear.
What also strikes the eye: with the exception of the “political” program and marketing packaging, it is unclear how Bitcoin is better than the modern European banking system. Moreover, it is much worse: in my Internet bank, zero commissions and instant payment within the country. In Bitcoin, commissions are inevitable, plus the operation takes 10 minutes.
The general conclusion: Bitcoin is a well-advertised project :)
Source: https://habr.com/ru/post/119527/
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