1 thought on “merkaba jewelry wholesale How to prevent tampering by Bitcoin”
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custom engraved jewelry wholesale Bitcoin networks will mainly ensure that the transactions issued by users and historical transactions will not be tampered with by the following two technologies:
formable encryption can ensure that the attacker cannot forge the signature of the owner of the account owner. ; The consensus algorithm can ensure that the historical transactions in the network will not be replaced by attackers; Oxly encryption
Aspicide plus algorithm 3 is currently widely used encryption technology, TLS Sites such as certificates and electronic signatures use asymmetric encryption algorithms to ensure safety. The asymmetric encryption algorithm also contains a public key (Public Key) and a private key (Secret Key). The data encrypted by private key can only be decrypted by the public key, and the data using the public key can only be decrypted by private key. Please click Enter Picture Description Figure 2 -asymmetric encryption features
Bitcoin uses asymmetric plus encryption algorithms to ensure the security of each transaction, each account in the network, each account in the network (Address) All the public keys in a pair of keys.
The note that it is extremely dangerous to use the website to generate Bitcoin address and private key. We do not know whether the website will store private keys. right.
The people can transfer to the account through the address above; the holder of the account can also use a private key signature transaction to other addresses. When we want to submit a stroke to the Bitcoin network When a new transaction, you need to build a transaction structure as shown below: { "txid": "", "hash": "": ", " version "" " : 1, "size": 224, "vsize": 224, "locktime": 0, "vin": [...], "vout": [...], "hex": "", "blockhash": "", "": 5, "time": , "blocktime": }
Next, we can use the private key to sign to sign all the fields in the entire transaction, and then pack the signature and transaction and pack up and packed the transaction Just confirm the confirmation of the Bitcoin network to the network.
In all the addresses of Bitcoin, the address currently holds more than 250,000 Bitcoin5, and the current market value is about $ 2 billion. In the case of only knowing the address, let's calculate how long it takes to get the private key to get the address. Bitcoin's private key has a total of 256 bits, that is, the possibility of 22562256:
This we do not have relatively fast cracking methods, and we can only use violent crack calculation private keys. Suppose we use IBM's supercomputer Summit6 in 2018, and it can do 1.4 ∗ ∗ ∗ ∗ 10171.4 ∗ 1017 floating -point calculation per second. The calculation of the floating point number is complicated), the time to find the corresponding private key to find the address of the $ 2 billion asset requires the following time:
The existence time of our entire universe is only one billionth of the private key time, so there is no current computing power without the current computing power. Under the premise of revolutionary breakthroughs, only the theoretical possibilities to obtain the public key to obtain the public key through the way of violent cracking, which is completely impossible in practice. consensus algorithm
Mysql and other databases to store data with behavioral units, while Bitcoin, the basic unit stored in the distributed database of Bitcoin, is the block. The tree, as shown in the figure below, the longest green chain in the figure is the main chain of the network. Please click Enter the picture description Figure 3 -Blockchain and main chain
How to make all nodes in the network reach the consensus on the next block The key issues that need to be solved. Only by allowing nodes to reach the data can ensure that past transactions will not be tampered with, but as a distributed database running on the public network, the scene it faces is very complicated. Distributed consistency issues.
The general Byzantine general is the fault tolerance problem of distributed and stricter fault -tolerant models of Leslie Lamport in The Byzantine Generals Privem paper. Under this model, the system will not have any restrictions on the nodes in the cluster. They can send random data and error data to other nodes, or they can choose the requests that do not respond to other nodes. More complicated.
The general Byzantine general described a following scenario. One group of generals commanded some army. Each general did not know whether the other generals were reliable and whether the information passed by other generals was reliable. But they need to choose whether to attack or retreat through voting: Please click Enter the picture description -Figure 4 -Byzantine general n The node realizes distributed consistency in the Byzantine General Scene. Bitcoin uses the following rules to allow multiple nodes to implement distributed consistency: This introduction of workload certificates — allows nodes to calculate hash that meets specific conditions before submitting a new block, replacing traditional distributed consistency algorithms The setting of one person, one vote (or one node, one vote); Thestable the longest chain is the setting of the main chain -only transactions on the main chain are considered legitimate transactions; The introduction of incentives- The nodes submitted to the block can get Bitcoin rewards;
In the above rules, each node will calculate hash on the longest chain and strive to submit legal blocks. However, once someone in the node has more than 51% of the computing power, it can change the history of the blockchain through strong computing power. Because the block is continuous, the change of the previous block will make the latter calculation of the latter computing failure. As shown in Figure 4, if the attacker needs to change the third yellow block in the main chain, it will be It is necessary to continuously build four blocks in order to complete the tampering of history. Other nodes will continue to calculate on this longer chain: Please click Enter the picture description R n 1 The code shown below can be calculated in the infinite long time. When the attacker holds 51% of the computing power, the probability of rewriting history 0-9 blocks 9: #include #include
double (double Q, int Z) { double p = 1.0 -q; double lambda = z * (q / p); dough sum = 1.0; int i, k; for (k = 0; k u003C= z; k ) { double poisson = exp (-lambda); for (i = 1; i u003C= k; i ) poisson * = lambda / i; sum -= poisson * (1 -pow (q / p, z -k)); } return abs to Return; }
int main () { for (int i = 0; i u003C10; i ) { Printf ("z =%d, p =%f n", i, (0.51, i)); } return 0; }
Through the above calculations, we will find that in the infinitely long period of time, the probability of 51% of the nodes that can initiate a 51% attack to modify history is 100%; It is relatively dynamic, and the nodes of the Bitcoin network are also avoiding 51% of the computing power of a single node, so it is difficult to tampering the history of Bitcoin. In some blockchain networks, 51% of attacks are still extremely common.
The prevention of 51% of the attack method is also very simple. In most blockchain networks, the transactions in the blockchain network have not been confirmed. The transaction in the block will be confirmed. The number of transactions in Bitcoin is 6, and the average 10 -minute Bitcoin generates a block, so the confirmation time of a transaction is about 60 minutes, which is also to ensure the sacrifice of safety. However, this method of increasing confirmation cannot guarantee 100% security, and we can only increase the cost of attackers as much as possible without affecting the user experience. Summary
The blockchain technology such as Bitcoin is still very interesting. As a distributed database, it will also encounter problems often encountered in distributed systems, such as Nodes are unreliable and other issues; at the same time, as a financial system and ledger, it will also face more complicated transaction confirmation and verification scenarios. The design of the Bitcoin network is very interesting. It is the product of the combination of technology and finance. It is worthy of our time behind it.
Bitcoin cannot prevent 100% prevent transaction and data tampering. The two technologies mentioned in the article can only ensure safety from a certain probability, and the possibility of reducing the success of the attacker is also the need for security fields. Face the eternal issue. We can explain the problem today in a more rigorous way -which technologies do Bitcoin use to increase the cost of attackers and reduce the probability of being tampered with transaction: Bitcoin uses asymmetric plus algorithm algorithms to ensure that the attacker is in During the limited time, the signature of the owner of the account cannot be forged; Bitcoin uses the consensus algorithm of the workload certificate and introduces the inspiration of bookkeeping to ensure that the historical transactions in the network will not be quickly replaced by the attacker;
In the above two methods, Bitcoin can ensure that historical transactions will not be tampered with and the security of funds in all accounts.
custom engraved jewelry wholesale Bitcoin networks will mainly ensure that the transactions issued by users and historical transactions will not be tampered with by the following two technologies:
formable encryption can ensure that the attacker cannot forge the signature of the owner of the account owner. ;
The consensus algorithm can ensure that the historical transactions in the network will not be replaced by attackers;
Oxly encryption
Aspicide plus algorithm 3 is currently widely used encryption technology, TLS Sites such as certificates and electronic signatures use asymmetric encryption algorithms to ensure safety. The asymmetric encryption algorithm also contains a public key (Public Key) and a private key (Secret Key). The data encrypted by private key can only be decrypted by the public key, and the data using the public key can only be decrypted by private key.
Please click Enter Picture Description
Figure 2 -asymmetric encryption features
Bitcoin uses asymmetric plus encryption algorithms to ensure the security of each transaction, each account in the network, each account in the network (Address) All the public keys in a pair of keys.
The note that it is extremely dangerous to use the website to generate Bitcoin address and private key. We do not know whether the website will store private keys. right.
The people can transfer to the account through the address above; the holder of the account can also use a private key signature transaction to other addresses. When we want to submit a stroke to the Bitcoin network When a new transaction, you need to build a transaction structure as shown below:
{
"txid": "",
"hash": "": ",
" version "" " : 1,
"size": 224,
"vsize": 224,
"locktime": 0,
"vin": [...],
"vout": [...],
"hex": "",
"blockhash": "",
"": 5,
"time": ,
"blocktime":
}
Next, we can use the private key to sign to sign all the fields in the entire transaction, and then pack the signature and transaction and pack up and packed the transaction Just confirm the confirmation of the Bitcoin network to the network.
In all the addresses of Bitcoin, the address currently holds more than 250,000 Bitcoin5, and the current market value is about $ 2 billion. In the case of only knowing the address, let's calculate how long it takes to get the private key to get the address. Bitcoin's private key has a total of 256 bits, that is, the possibility of 22562256:
This we do not have relatively fast cracking methods, and we can only use violent crack calculation private keys. Suppose we use IBM's supercomputer Summit6 in 2018, and it can do 1.4 ∗ ∗ ∗ ∗ 10171.4 ∗ 1017 floating -point calculation per second. The calculation of the floating point number is complicated), the time to find the corresponding private key to find the address of the $ 2 billion asset requires the following time:
1.15 ∗ 1077365 ∗ 86400 ∗ 1.4 ∗ 1017 = 2.9 ∗ 1052 years 1.15 ∗ ∗ 1077365 ∗ 86400 ∗ 1.4 ∗ 1017 = 2.9 ∗ 1052
The existence time of our entire universe is only one billionth of the private key time, so there is no current computing power without the current computing power. Under the premise of revolutionary breakthroughs, only the theoretical possibilities to obtain the public key to obtain the public key through the way of violent cracking, which is completely impossible in practice.
consensus algorithm
Mysql and other databases to store data with behavioral units, while Bitcoin, the basic unit stored in the distributed database of Bitcoin, is the block. The tree, as shown in the figure below, the longest green chain in the figure is the main chain of the network.
Please click Enter the picture description
Figure 3 -Blockchain and main chain
How to make all nodes in the network reach the consensus on the next block The key issues that need to be solved. Only by allowing nodes to reach the data can ensure that past transactions will not be tampered with, but as a distributed database running on the public network, the scene it faces is very complicated. Distributed consistency issues.
The general Byzantine general is the fault tolerance problem of distributed and stricter fault -tolerant models of Leslie Lamport in The Byzantine Generals Privem paper. Under this model, the system will not have any restrictions on the nodes in the cluster. They can send random data and error data to other nodes, or they can choose the requests that do not respond to other nodes. More complicated.
The general Byzantine general described a following scenario. One group of generals commanded some army. Each general did not know whether the other generals were reliable and whether the information passed by other generals was reliable. But they need to choose whether to attack or retreat through voting:
Please click Enter the picture description
-Figure 4 -Byzantine general
n The node realizes distributed consistency in the Byzantine General Scene. Bitcoin uses the following rules to allow multiple nodes to implement distributed consistency:
This introduction of workload certificates — allows nodes to calculate hash that meets specific conditions before submitting a new block, replacing traditional distributed consistency algorithms The setting of one person, one vote (or one node, one vote);
Thestable the longest chain is the setting of the main chain -only transactions on the main chain are considered legitimate transactions;
The introduction of incentives- The nodes submitted to the block can get Bitcoin rewards;
In the above rules, each node will calculate hash on the longest chain and strive to submit legal blocks. However, once someone in the node has more than 51% of the computing power, it can change the history of the blockchain through strong computing power. Because the block is continuous, the change of the previous block will make the latter calculation of the latter computing failure. As shown in Figure 4, if the attacker needs to change the third yellow block in the main chain, it will be It is necessary to continuously build four blocks in order to complete the tampering of history. Other nodes will continue to calculate on this longer chain:
Please click Enter the picture description
R n
1 The code shown below can be calculated in the infinite long time. When the attacker holds 51% of the computing power, the probability of rewriting history 0-9 blocks 9:
#include
#include
double (double Q, int Z) {
double p = 1.0 -q;
double lambda = z * (q / p);
dough sum = 1.0;
int i, k;
for (k = 0; k u003C= z; k ) {
double poisson = exp (-lambda);
for (i = 1; i u003C= k; i )
poisson * = lambda / i;
sum -= poisson * (1 -pow (q / p, z -k));
}
return abs to Return;
}
int main () {
for (int i = 0; i u003C10; i ) {
Printf ("z =%d, p =%f n", i, (0.51, i));
}
return 0;
}
Through the above calculations, we will find that in the infinitely long period of time, the probability of 51% of the nodes that can initiate a 51% attack to modify history is 100%; It is relatively dynamic, and the nodes of the Bitcoin network are also avoiding 51% of the computing power of a single node, so it is difficult to tampering the history of Bitcoin. In some blockchain networks, 51% of attacks are still extremely common.
The prevention of 51% of the attack method is also very simple. In most blockchain networks, the transactions in the blockchain network have not been confirmed. The transaction in the block will be confirmed. The number of transactions in Bitcoin is 6, and the average 10 -minute Bitcoin generates a block, so the confirmation time of a transaction is about 60 minutes, which is also to ensure the sacrifice of safety. However, this method of increasing confirmation cannot guarantee 100% security, and we can only increase the cost of attackers as much as possible without affecting the user experience.
Summary
The blockchain technology such as Bitcoin is still very interesting. As a distributed database, it will also encounter problems often encountered in distributed systems, such as Nodes are unreliable and other issues; at the same time, as a financial system and ledger, it will also face more complicated transaction confirmation and verification scenarios. The design of the Bitcoin network is very interesting. It is the product of the combination of technology and finance. It is worthy of our time behind it.
Bitcoin cannot prevent 100% prevent transaction and data tampering. The two technologies mentioned in the article can only ensure safety from a certain probability, and the possibility of reducing the success of the attacker is also the need for security fields. Face the eternal issue. We can explain the problem today in a more rigorous way -which technologies do Bitcoin use to increase the cost of attackers and reduce the probability of being tampered with transaction:
Bitcoin uses asymmetric plus algorithm algorithms to ensure that the attacker is in During the limited time, the signature of the owner of the account cannot be forged;
Bitcoin uses the consensus algorithm of the workload certificate and introduces the inspiration of bookkeeping to ensure that the historical transactions in the network will not be quickly replaced by the attacker;
In the above two methods, Bitcoin can ensure that historical transactions will not be tampered with and the security of funds in all accounts.