Blockchain flash loan attacked by hackers
at present, the vast majority of digital currency transactions are concted in exchanges. Among the numerous exchanges, bitfinex, binance, okex and so on are well-known
However, bitcoin and other digital currencies, as decentralized assets, have to be traded in a centralized exchange, which seems to have hidden contradictions and dangers1. Problems and challenges of stock exchanges=“ https://iknow-pic.cdn.bcebos.com/fd039245d688d43fdf16c83b761ed21b0ff43bbf ">
in February 2014, Mt. GOx, the world's largest bitcoin exchange at that time, was stolen 850000 bitcoins, and the price of bitcoin suffered a" cliff "crash on that day. Later, it was revealed that Mt. GOx was in fact a thief, and only 7000 bitcoins were actually stolen
in August 2016, bitfinex, the largest U.S. dollar bitcoin trading platform, suffered a security vulnerability, resulting in the theft of 120000 bitcoins, which was worth $65 million at that time. If converted into the price in December 2017, it would be worth nearly $2 billion
on December 19, 2017, South Korea's youbit exchange was attacked by hackers and lost 4000 bitcoins, and the exchange declared bankruptcy
on December 21, 2017, the Ukrainian liqui exchange was stolen 60000 bitcoins, and the unit price of bitcoin plummeted by US $2000
in 2018, such a drama will only continue
in addition to the threat of hackers, traditional exchanges also have some inherent shortcomings, such as lack of supervision and inefficiency. The security of the exchange for investors can only rely on its own credit, and the cost of running is very low. The stock exchange is regulated at the national level, but there is no such sword of Damocles on the top of the digital currency exchange. Moreover, in an exchange, the same order can only be submitted to one exchange. After the user places an order, the funds used for the transaction will be frozen and can only wait for the completion or cancellation of the transaction. These are undoubtedly inefficient
All in all, the problems of exchanges are the problems of centralization2. Decentralization of exchanges=“ https://iknow-pic.cdn.bcebos.com/86d6277f9e2f070889a173c9e224b899a801f257 ">
(1) the progress of the exchange itself
the upgrade of security means is various. At present, the best use is cold wallet, that is, to keep the digital currency in the offline U disk. At the end of 2017, when the YouTube exchange was attacked, 75% of its assets were withdrawn into the cold purse in time to avoid greater losses. However, it seems to be a helpless way to protect the online assets by offline means. Of course, there should be many other methods, which will not be repeated here
(2) the representative of cross ledger transaction is ripple network, and the operating company is ripple labs, which is a semi centralized system. Ripple is a decentralized clearing agreement. In order to solve the high cost and delay of inter-bank clearing, its base currency is XRP. Ripple network can connect all kinds of assets, such as US dollar, RMB, Japanese yen, bitcoin, etc. to its own network. In this system, U.S. dollars or bitcoin can be converted into reborn currency, and then reborn currency can circulate freely in the network, just as a highway is built between various assets. Due to the support of major banking institutions, the reborn currency achieved nearly 300 times growth in 2017
(3) decentralized exchange
some teams try to use blockchain technology to build a decentralized exchange. This kind of decentralized exchange, to some extent, is an extension of cross ledger trading
bitshares is the most representative of early rising projects. It builds a blockchain development platform with servers scattered all over the world. Even if some of them are attacked, the system will not collapse. Anyone can transfer money and borrow money freely on this platform, and can also quickly build a centralized exchange based on this platform. In order to ensure stable value, bitstocks also require three times of digital assets as collateral. At present, bitstocks are running fairly well
later, with the development of Ethereum and smart contract, the x x protocol came into being. This is an open protocol running in the Ethereum blockchain and a decentralized exchange in the Ethereum ecosystem. The agreement has attracted many investors. At present, it has completed financing and started to build open source software tools and infrastructure. Of course, there are many competitors. Ether Delta, IDEX and oasis DEX are trying to provide similar functions. Moreover, it is a smart contract system based on Ethereum, which only supports erc20 token. If other smart contract public chains start to rise, the demand will be reced
in addition, there are some teams that are entering, such as the domestic road seal agreement, looping (LRC) in English. They adopted a design similar to the X protocol, and also introced a fast payment function similar to the lightning network. It is characterized by trying to match multiple exchanges, the user's order can be broadcast to multiple exchanges, and completed by different exchanges. Moreover, the user can still use the account funds after placing an order, and the user's behavior of transferring part or all of the funds is equivalent to partial or total cancellation. To some extent, it improves the breadth and timeliness of the transaction. However, this system seems to have damaged the "power" of the existing exchanges. Whether we can persuade everyone to play together will be a difficult problem
At present, there is still a long way to go for the construction of decentralized exchange. In 3-5 years, traditional exchange will still be the main battlefield of digital currency However, in the future, it is worth looking forward to let the decentralized digital currency get rid of the shackles of centralizationthen it seems that the proct does have the flavor of sweet scented osmanthus, but it is lighter, the color is still transparent, there is no yellow or orange in imagination, and there is no petal, high technology, Don't you understand?
Osmanthus fragrans doesn't belong to Osmanthus fragrans. Cigui, also known as Huaye tree, mouse thorn; It is a plant of Ilex family. Evergreen shrubs or small trees, landscaping tree species. It is mainly distributed in the middle and lower reaches of the Yangtze River in China
There are four groups of Osmanthus fragrans, namely Dangui, Jingui, Yingui and sijigui. Among them, Osmanthus fragrans, Osmanthus fragrans and Osmanthus fragrans all bloom in autumn and are collectively called August osmanthus. Generally, it takes at least 10 years for Osmanthus fragrans seedlings to bloom in open field. For newly transplanted seedlings, it is not allowed to apply fertilizer too early. Sowing seedlings, after two years of cultivation, the next spring can be transplanted, flowering period in ten yearsbecause the connected computers are controlled by the policy settings of the router
the most important thing is to allocate your bandwidth reasonably. In theory, if you download resources from a computer in your network segment, if your router does not allocate bandwidth, it may cause the computers in the whole network segment to get stuck on the Internet
if the distribution is reasonable and the router is powerful, then 200 computers can be easily handled.
"recently, a girl under 30 years old in our building lost more than 300000 yuan because of speculating in virtual currency, and a boy nearby lost more than 700000 yuan because of investing in bitcoin. Therefore, we are now sending police reminder leaflets door to door, and asking the person in charge of the family to fill in the information. On the one hand, we are alert to all kinds of new means of Internet fraud; In addition, it is also a way to find out the people who are involved in investment fraud hidden everywhere. " On February 4, the community police of a community in Songjiang District of Shanghai told China times
the police also said that many new types of fraud no longer focus on the middle-aged and the elderly, but on the "post-90s" and conct virtual currency investment fraud through wechat and QQ group
in fact, with the recent sharp rise and fall of virtual digital currency represented by bitcoin, a wave of air currency has surged, which makes many young people in China think that there are investment opportunities. However, some bloody cases let the Shanghai public security department issue a police warning to the public<
the "conspiracy" after the big rise of bitcoin
"bitcoin is too expensive for ordinary people to play, but the sharp rise and fall of bitcoin driven by bitcoin market needs attention. The current chaotic market does not rule out the conspiracy of head makers working together." On February 5, Wang Heng, senior analyst of Shanghai virtual digital currency, pointed out this analysis
recently, dogecoin, the "old ancestor" of air currency, suddenly rose sharply after January 28. In the morning of January 29, Beijing time, Elon Musk, the founder of Tesla, released a social tweet with pictures containing information about dogecoin. As musk has mentioned Dog Coin publicly for many times, the picture is considered to be his platform again. At that time, the dog coin price rose about 260% in 24 hours; In the afternoon of January 29, the price of dog currency and US dollar stable currency trading pair reached the highest of about US $0.085 in okex, coin an and fire currency exchanges, with a 24-hour increase of more than 900%
according to the data of coinmarketcap, the price of doggie has not exceeded US $0.01 for a long time since February to December, 2018. This rise has made doggie top the list of major exchanges, with its market value approaching us $10 billion, once ranking among the top ten cryptocurrencies in market value. Compared with the new currency of small market value, the dog currency of "longevity" has been online as early as 2014. For the soaring dog currency, some people in the cryptocurrency instry are "envious" while calling out that they can't understand it
"behind the sharp rise of dog money, in fact, it is the continuation of the war between American retail investors and Wall Street institutional bears. Whether it's the soaring stock price of game station (GME) or the rising dog coin, it can be explained by Robert Schiller's "narrative economics". In addition, with the promotion of the media, a kind of popular thinking has been formed, and people have joined in this narrative, which has led to the rise of relevant asset prices. " In this regard, William, chief analyst of okex research, said
however, in the view of the instry, dog money is a real "air money". Even the founder of dogcoin himself admitted that the development of dogcoin was just a joke, but he didn't expect that dogcoin was still flowing around the world and had a market value of $2 billion
according to the data, dogcoin was born in 2013 by Australian Jackson Palmer. In 2018, Palmer published a signed article on the vice website, saying that he participated in ecation in the field of cryptocurrency and held a variety of cryptocurrencies, including dog coins worth less than $50
"dog coin is an imitation of encryption token, which is active in reddit community because of its low price and community friendliness. Since then, opportunists have cheated millions of dollars in the dogcoin community. In 2015, the swindlers disappeared and the community's interest in dog money declined. At that time, I decided not to participate in dogcoin and cryptocurrency any more, and gave the development of dogcoin to the trust and community team members. It never occurred to me that my dog coin, which I developed as a joke, would still flow around the world in 2018, with a market value of $2 billion. " Palmer pointed out in his article at that time
"just as the founders themselves call Dog Coin an imitation token, there are still so many people around the world chasing it up and speculating on it repeatedly. The most important factor is that the price is too low. For the general public, anyone can participate in the investment of Dog Coin which is only a fraction of RMB, even if it loses money, But what the makers attract is the post-90s. " Wang Heng said.