Bitcoin malicious miner
after the Second World War, with the world economy becoming more prosperous and the fashion becoming bolder, in the 1960s, miniskirts and hippies brought women's skirts to the highest point. Then the world went through the oil crisis and so on; In the 1990s, the US stock market rose for the longest time in history. As a result, women's skirts changed from long skirts to short skirts again
the most amazing thing happened in 1987. Originally, the popular style of that year was miniskirts, but when October came, miniskirts suddenly became out of fashion. In the autumn of that year, the US stock market ushered in the second huge decline.
Nakamoto's mining is unreliable
On October 31, 2008, a person named Nakamoto published a research report called bitcoin: a peer-to-peer cash payment system on a secret cryptography discussion group, which elaborated the new idea of e-moneysoon after, he developed an operating system for bitcoin issuing, trading and account management on the platform of P2P (peer-to-peer or person to person) peer-to-peer network and distributed database, combining the working mode of open source software and block cipher in cryptography
the system enables all nodes throughout the peer-to-peer network to reach network agreements according to their seed files, so as to ensure fairness, security and reliability in currency issuance, management and circulation
after the advent of bitcoin, it quickly attracted the following and attention of geeks. However, what is puzzling is that after leaving bitcoin in cyberspace, Nakamoto Tsung has not been as frequently active in the bitcoin community as before, but graally faded out of the public's sight
in the spring of 2011, after leaving behind the sentence "I started to do something else", Nakamoto completely evaporated from the Internet space. No one can know his real identity, only that this mysterious figure left 2 million bitcoins for himself in the earliest block he owned, and these bitcoins have not been passive yet
people want to see the true face of Nakamoto, and even use the powerful human flesh search tool to search, which is still fruitless, Even the two Google engineers who later took charge of repairing the bitcoin project claimed that they had never found and met Nakamoto at the scene
extended data mining is a process of increasing bitcoin money supply. Mining also protects the security of the bitcoin system, prevents fraulent transactions, and avoids "double payment", which means spending the same bitcoin multiple times
miners provide algorithms for bitcoin network in exchange for the opportunity of bitcoin reward. The miners verify each new transaction and record it in the general ledger
every 10 minutes, a new block will be "mined", and each block contains all the transactions from the generation of the previous block to the present, which are added to the blockchain in turn
we call the transactions included in the block and added to the blockchain "confirmed" transactions. Only after the transaction is "confirmed" can the new owner spend the bitcoin he gets in the transaction
No, mining, as the cornerstone of blockchain development, is impossible for miners to disappear. Not all of them are digging for bitcoin now. Many people are digging for Monroe and Ethereum, with high profits
recently, I'm using the two currencies of ha Yu miner to earn a pack of cigarettes every day
1. Packet filtering
is firewall with packet filtering? Yes, that's right! According to the definition of firewall, any way that can effectively prevent illegal network connection is considered as firewall. Early firewalls usually use the set conditions to monitor the characteristics of packets to decide whether to release or block. Packet filtering is a very important feature. Although there are many new ideas of firewall technology, packet filtering is still a very important part, just as the primary function of layer 4 switch is to have the basic function of packet forwarding. Through packet filtering, firewall can block attacks, prohibit external / internal access to some sites, and limit the traffic and connection number of each IP
2. Transparent forwarding of packets
in fact, firewalls are usually set up in front of servers providing certain services. If it is represented by a schematic diagram, it is server firewall guest. Users' requests for access to the server and the information that the server feeds back to users need to be forwarded through the firewall. Therefore, many firewalls have the ability of gateway
3. Block external attacks
if the information sent by the user is not allowed by the firewall settings, the firewall will block it immediately to prevent it from entering the server behind the firewall
4. Log attacks
if necessary, in fact, the firewall can log all attacks. However, for the sake of efficiency, IDS is generally responsible for recording attacks, which will be mentioned later
the above are the basic characteristics of all firewalls. Although it is very simple, firewall technology is graally developed on this basis
the specific function of firewall:
1. First of all, it is natural to support the umbrella of the network. Firewalls will make their own rules. Those that comply with the rules will be released, and those that do not comply with the rules will be prohibited. Of course, these rules can be made by the network administrator himself, but some firewalls may only use built-in rules
2. The next step is to strengthen the network security strategy. Originally, the network security problem is handled by each security software independently, and the firewall can effectively configure all security software on the firewall, and call it uniformly with the firewall as the center. The centralized security management of firewall is more economical and secure
3. The firewall can also effectively record the activities on the Internet. If the access passes through the firewall, it can record all of them and form a log for users to view. When a suspicious situation occurs, the firewall will automatically issue appropriate alerts, and provide detailed information for users to query. Through this information, we can effectively grasp whether the current network is safe or not, and whether further configuration is needed to ensure safety
4. Firewalls can limit the exposure of user points. Firewall can separate the network into a network segment, and each network segment is independent of each other. When a network segment has a problem, it will not affect other network segments, which can effectively prevent the whole network security from being affected by a network segment problem
5. Another important function of the firewall is to prevent information leakage. Privacy should be the most concerned issue of every Internet user. Now is the sensitive period of privacy leakage, so it is more concerned by users. The firewall can block DNS information in the internal network, so that the domain name and IP address of the local computer will not be known by the outside world, Can effectively prevent information leakage
6. Of course, the role of firewall is not only in the scope of security, it also supports the enterprise internal network technology system (virtual private network) with internet service characteristics. Many firewalls have functions.