How many months is bitcoin in 2011
By the end of July 2020, bitcoin is now 98 yuan
the bitcoin address and private key appear in pairs, and their relationship is just like the bank card number and password. A bitcoin address is like a bank card number, which records how much bitcoin you have on it. You can generate bitcoin address at will to store bitcoin. When each bitcoin address is generated, a corresponding private key of the address will be generated
extended materials:
whenever bitcoin comes into the view of mainstream media, mainstream media always ask some mainstream economists to analyze bitcoin. Earlier, these analyses always focused on whether bitcoin was a scam. Now the analysis is always focused on whether bitcoin can become the mainstream currency in the future. The focus of the debate is often on the deflationary nature of bitcoin
many bitcoin players are attracted by the fact that bitcoin can not be issued at will. The attitude of bitcoin players is quite the opposite, and the attitude of economists is polarized compared with the fixed amount of 21 million bitcoin
When bitcoin first appeared in 2009, its price was less than 1 cent. One dollar could be converted into 1300 bitcoins, that is to say, seven yuan could be converted into 1300 bitcoins
on May 5, 2017, bitfinex, an overseas digital currency trading platform, quoted a price. Bitcoin once hit US $1700, about RMB 11737
extended information:
in China, some Taobao stores have also begun to accept the use of bitcoin, and businesses will graally increase
in October 2013, the first bitcoin quarterly, one bit, was released
on October 15, 2013, the network accelerator service of the network announced its support for bitcoin
on October 26, 2013, btcmini reported that GBL was hacked
on October 31, 2013, Lei Teng, a famous Internet lawyer, proposed the event of "filing a case to investigate the closure of GBL bitcoin trading platform as soon as possible", analyzed the "value function" and "use function" of bitcoin, and bitcoin should be governed by relevant laws
on December 5, 2013, notice of the Ministry of instry and information technology of the people's Bank of China, China Banking Regulatory Commission, China Securities Regulatory Commission and China Insurance Regulatory Commission on preventing bitcoin risk: bitcoin is a specific virtual commodity; Bitcoin trading is a kind of commodity trading on the Internet. Ordinary people have the freedom to participate in it at their own risk
on September 4, 2017, the announcement of the people's Bank of China Central Network Information Office, Ministry of instry and information technology, State Administration for Instry and commerce, China Banking Regulatory Commission, China Securities Regulatory Commission and China Insurance Regulatory Commission on preventing the risk of token issuance financing: it is prohibited to engage in token issuance financing activities (ICO)
the trading platform shall not engage in the exchange business between legal tender and token, or virtual currency, or buy or sell token or virtual currency as a central counter party, or provide pricing, information intermediary and other services for token or virtual currency
on November 2, 2018, the people's Bank of China released the 12th topic of China financial stability report 2018, which talked about "encrypted assets"
Bitcoin is a kind of network virtual currency. Bitcoin network generates new bitcoin through "mining". In essence, the so-called "mining" is to use computers to solve a complex mathematical problem to ensure the consistency of bitcoin network distributed accounting system. Assuming that the mining computing power is 100 mhash / s and the total computing power is 4000 ghash / s per day, 3600 bitcoins can be g out every 24 hours
China's computing power has accounted for more than 75% of the world, that is to say, 75% of bitcoin in the world is made in China. How long does it take to dig a bitcoin
bitcoin used to be very good at "digging", which can be done by ordinary computer CPU, and it can automatically "solve problems" by downloading software. But with the rise of currency price, more and more people want to "solve the problem", and the difficulty of mining is also increasing. Now, the amount of computation needed to dig a bitcoin is beyond the reach of ordinary people. Ordinary computers can't afford it
instry insiders said that in 2014, 100 bitcoins were generated from 500000 yuan of electricity charge per day, and the cost of electricity charge alone was 5000 yuan per coin. But now, the same cost has more than doubled, and the electricity cost of each bitcoin is as high as 10000 yuan
in the generation mechanism of bitcoin, mining reward is decreasing. At the beginning of the birth of bitcoin, the miners could get 50 bitcoins for each page of the ledger, and then 25 bitcoins for each page of the ledger, decreasing in turn. It's like digging gold. At first, it's more and less. The time point at which each new reward is reced by half is called half bitcoin proction
assuming that the mining computing power is 100 mhash / s, the total computing power is 4000 ghash / s per day in 2014, and 3600 bitcoins are g out every 24 hours
now, we can understand the difficulty of bitcoin digging in this way, which is equivalent to 100 million dice throwing numbers less than 100 million and 50 million. Whoever throws them first will get the bookkeeping right. At this point, 1050 million is a hash value. The process of throwing dice is called hash collision. The unit of mining power is the number of hash collisions per second
at present, the computing power of bitcoin in the whole network has reached 2.36 billion hash collisions per second, which is equivalent to the number of water droplets in more than 200000 50 meter long standard swimming pools. But even with such a large amount of computing power, it will take about 10 minutes to hit a hash value that meets the requirements
in 2012, bitcoin's output was halved for the first time, and in July 2016, bitcoin's output was halved for the second time. At present, 12.5 bitcoins are awarded for recording one page of account book. The next halving will take place around 2020, and the total number of bitcoins will not increase by 2040, with a total of 21 million
Related videos: how long does it take to dig a bitcoin
The first half: on November 28, 2012, the 210000 block was excavated, and the block reward was halved for the first time, and the block reward was 25btc
the second half: on July 10, 2016, starting from the 420.000 block, the bitcoin reward of each block was halved to 12.5btc
the third half: on May 12, 2020, bitcoin reward will be halved to 6.25btc
the next half: on May 9, 2024, bitcoin reward will be halved to 3.125btc
About 400 percent
when bitcoin first appeared in 2009, one dollar could buy almost 1300 bitcoins. Before April 2011, the price of each bitcoin was always below $1. In June 2011, the highest price of bitcoin rose to $30. Then, the price almost fell within a week. In 2012, the price of bitcoin once fell below $2
further dropped to $114 on January 14, 2015. Since then, bitcoin has begun to rise again. In 2017, after the bitcoin ETF fund was rejected by the US Securities Regulatory Commission, bitcoin plummeted by $315 to below $1000. After that, it rose again. In the first four months of this year, the price of bitcoin and an ounce of gold were almost equal
However, with the strong rise of bitcoin in this round, the price of bitcoin has exceeded the price of an ounce of gold. On April 26, the price of bitcoin was $1282.97, compared with $1264 for an ounce of gold. Bitcoin has surpassed gold in price
extended data
in 2016, there were dozens of bitcoin exchanges in the world, and the trading volume of bitcoin in most countries and regions increased sharply. Among the countries and regions with the highest growth rate, the trading volume of bitcoin in Japan is second only to China, ranking second in the world; The local bitcoin trading volume in Venezuela increased by more than 913%
South Korea has become the sixth largest bitcoin trading market in the world, Korean people can buy bitcoin from a large number of convenience stores, and korbit's trading volume currently accounts for 70% of the South Korean market; Local bitcoin transactions in Colombia increased by about 370%; Bitcoin markets in Malaysia, Russia and Australia are also developing rapidly. Bitcoin trading in China once accounted for more than 80% of the global trading volume
1. Transfer platform: the current domestic trading is closed, and it can be transferred to foreign trading platforms
2. Cash withdrawal: users who do not want to hold bitcoin can make cash withdrawal
Third, storage: users who do not want to trade but continue to hold coins can save them in bitcoin wallets such as coin packets.
- I specifies the packet capture network card
- s specifies the packet capture length, and only the packet header is captured by default
- W saves the packet capture content, and then it is more convenient to use software such as Wireshark. If you want to scroll through the screen, ignore this option
UDP and port 67 and port 68: the filter conditions of DHCP message, UDP protocol, ports 67 and 68
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <netdb.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/ip.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <netpacket/packet.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <arpa/inet.h>
#include <errno.h>
/* 接收缓冲区大小 */
#define RCV_BUF_SIZE 1024 * 5
/* 接收缓冲区 */
static int g_iRecvBufSize = RCV_BUF_SIZE;
static char g_acRecvBuf[RCV_BUF_SIZE] = {0};
/* 物理网卡接口,需要根据具体情况修改 */
static const char *g_szIfName = "eth1";
/* 以太网帧封装的协议类型 */
static const int g_iEthProId[] = { ETHERTYPE_PUP,
ETHERTYPE_SPRITE,
ETHERTYPE_IP,
ETHERTYPE_ARP,
ETHERTYPE_REVARP,
ETHERTYPE_AT,
ETHERTYPE_AARP,
ETHERTYPE_VLAN,
ETHERTYPE_IPX,
ETHERTYPE_IPV6,
ETHERTYPE_LOOPBACK
};
static const char g_szProName[][24] = {
"none", "xerox pup", "sprite", "ip", "arp",
"rarp", "apple-protocol", "apple-arp",
"802.1q", "ipx", "ipv6", "loopback"
};
/* 输出MAC地址 */
static void ethmp_showMac(const int iType, const char acHWAddr[])
{ int i = 0;
if (0 == iType)
{
printf("SMAC=[");
}
else
{
printf("DMAC=[");
}
for(i = 0; i < ETHER_ADDR_LEN - 1; i++)
{
printf("%02x:", *((unsigned char *)&(acHWAddr[i])));
}
printf("%02x] ", *((unsigned char *)&(acHWAddr[i])));
}
/* 物理网卡混杂模式属性操作 */
static int ethmp_setPromisc(const char *pcIfName, int fd, int iFlags)
{ int iRet = -1;
struct ifreq stIfr;
/* 获取接口属性标志位 */
strcpy(stIfr.ifr_name, pcIfName);
iRet = ioctl(fd, SIOCGIFFLAGS, &stIfr);
if (0 > iRet)
{ perror("[Error]Get Interface Flags");
return -1;
}
if (0 == iFlags)
{ /* 取消混杂模式 */
stIfr.ifr_flags &= ~IFF_PROMISC;
}
else
{ /* 设置为混杂模式 */
stIfr.ifr_flags |= IFF_PROMISC;
}
iRet = ioctl(fd, SIOCSIFFLAGS, &stIfr);
if (0 > iRet)
{ perror("[Error]Set Interface Flags");
return -1;
}
return 0;
}
/* 获取L2帧封装的协议类型 */
static char *ethmp_getProName(const int iProNum)
{ int iIndex = 0;
for(iIndex = 0; iIndex < sizeof(g_iEthProId) / sizeof(g_iEthProId[0]); iIndex++)
{ if (iProNum == g_iEthProId[iIndex])
{
break;
}
}
return (char *)(g_szProName[iIndex + 1]);
}
/* Init L2 Socket */
static int ethmp_initSocket()
{ int iRet = -1;
int fd = -1;
struct ifreq stIf;
struct sockaddr_ll stLocal = {0};
/* 创建SOCKET */
fd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
if (0 > fd)
{ perror("[Error]Initinate L2 raw socket");
return -1;
}
/* 网卡混杂模式设置 */
ethmp_setPromisc(g_szIfName, fd, 1);
/* 设置SOCKET选项 */
iRet = setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &g_iRecvBufSize,sizeof(int));
if (0 > iRet)
{ perror("[Error]Set socket option");
close(fd);
return -1;
}
/* 获取物理网卡接口索引 */
strcpy(stIf.ifr_name, g_szIfName);
iRet = ioctl(fd, SIOCGIFINDEX, &stIf);
if (0 > iRet)
{ perror("[Error]Ioctl operation");
close(fd);
return -1;
}
/* 绑定物理网卡 */
stLocal.sll_family = PF_PACKET;
stLocal.sll_ifindex = stIf.ifr_ifindex;
stLocal.sll_protocol = htons(ETH_P_ALL);
iRet = bind(fd, (struct sockaddr *)&stLocal, sizeof(stLocal));
if (0 > iRet)
{ perror("[Error]Bind the interface");
close(fd);
return -1;
}
return fd;
}
/* 解析Ethernet帧首部 */
static int ethmp_parseEthHead(const struct ether_header *pstEthHead)
{ unsigned short usEthPktType;
if (NULL == pstEthHead)
{ return -1;}
/* 协议类型、源MAC、目的MAC */
usEthPktType = ntohs(pstEthHead->ether_type);
printf(">>>\nEth-Pkt-Type:0x%04x(%s) ", usEthPktType, ethmp_getProName(usEthPktType));
ethmp_showMac(0, pstEthHead->ether_shost);
ethmp_showMac(1, pstEthHead->ether_dhost);
return 0;
}
/* 解析IP数据包头 */
static int ethmp_parseIpHead(const struct ip *pstIpHead)
{ struct protoent *pstIpProto = NULL;
if (NULL == pstIpHead)
{ return -1;}
/* 协议类型、源IP地址、目的IP地址 */
pstIpProto = getprotobynumber(pstIpHead->ip_p);
if(NULL != pstIpProto)
{ printf("\nIP-Pkt-Type:%d(%s) ", pstIpHead->ip_p, pstIpProto->p_name); }
else
{ printf("\nIP-Pkt-Type:%d(%s) ", pstIpHead->ip_p, "None");}
printf("SAddr=[%s] ", inet_ntoa(pstIpHead->ip_src));
printf("DAddr=[%s]\n", inet_ntoa(pstIpHead->ip_dst));
return 0;
}
/* 数据帧解析函数 */
static int ethmp_parseFrame(const char *pcFrameData)
{ int iRet = -1;
struct ether_header *pstEthHead = NULL;
struct ip *pstIpHead = NULL;
/* Ethnet帧头解析 */
pstEthHead = (struct ether_header*)g_acRecvBuf;
iRet = ethmp_parseEthHead(pstEthHead);
if (0 > iRet)
{ return iRet;}
/* IP数据包类型 */
pstIpHead = (struct ip *)(pstEthHead + 1);
iRet = ethmp_parseIpHead(pstIpHead);
return iRet;
}
/* 捕获网卡数据帧 */
static void ethmp_startCapture(const int fd)
{ int iRet = -1;
socklen_t stFromLen = 0;
/* 循环监听 */
while(1)
{ /* 清空接收缓冲区 */
memset(g_acRecvBuf, 0, RCV_BUF_SIZE);
/* 接收数据帧 */
iRet = recvfrom(fd, g_acRecvBuf, g_iRecvBufSize, 0, NULL, &stFromLen);
if (0 > iRet)
{ continue;}
/* 解析数据帧 */
ethmp_parseFrame(g_acRecvBuf);
}
}
/* Main */
int main(int argc, char *argv[])
{ int iRet = -1;
int fd = -1;
/* 初始化SOCKET */
fd = ethmp_initSocket();
if(0 > fd) {
return -1;
}
/* 捕获数据包 */
ethmp_startCapture(fd);
/* 关闭SOCKET */
close(fd);
return 0;
}
编译命令
gcc -o a a.c
./a
实现效果图
...
>>>Eth-Pkt-Type:0x0800(ip) SMAC=[00:1a:92:ef:b6:dd] DMAC=[00:24:7e:dc:99:18] IP-Pkt-Type:6(tcp) SAddr=[192.168.0.111] DAddr=[192.168.0.100]
>>> Eth-Pkt-Type:0x0800(ip) SMAC=[00:24:7e:dc:99:18] DMAC=[00:1a:92:ef:b6:dd] IP-Pkt-Type:6(tcp) SAddr=[192.168.0.100] DAddr=[192.168.0.111]
>>> Eth-Pkt-Type:0x0800(ip) SMAC=[00:24:7e:dc:99:18] DMAC=[00:1a:92:ef:b6:dd] IP-Pkt-Type:1(icmp) SAddr=[192.168.0.100] DAddr=[192.168.0.111]
>>> Eth-Pkt-Type:0x0800(ip) SMAC=[00:1a:92:ef:b6:dd] DMAC=[00:24:7e:dc:99:18] IP-Pkt-Type:1(icmp) SAddr=[192.168.0.111] DAddr=[192.168.0.100]
>>> Eth-Pkt-Type:0x0800(ip) SMAC=[00:1a:92:ef:b6:dd] DMAC=[00:24:7e:dc:99:18] IP-Pkt-Type:6(tcp) SAddr=[192.168.0.111] DAddr=[192.168.0.100]
...