***Bitcoin and blockchain

mob604757044d68 2021-07-19 21:19:03 阅读数:767

bitcoin blockchain

Turn on the TV. , Open the tech blog , It's hard to avoid being inundated by a lot of bitcoin or blockchain messages . The biggest reason bitcoin is so popular , Because it went up last year 2000% The price of . Doubling the value of bitcoin , It also triggered the attention to its supporting technology blockchain , Although blockchain may be a better choice for long-term investment .


Blockchain technology is ready to have a significant impact on our world .2017 Beginning of the year ,《 Harvard Business Review 》 Think , Blockchain has the potential to create a new foundation for economic and social systems .2017 year 1 The world economic forum report in May predicted , To 2025 year , The global GDP Of 10% Will be stored in blockchain or blockchain related technologies . If you're interested in what you're going to carry in 10 years 10% GDP Little is known about our technology , Then you should really start learning .

What is blockchain ?

Blockchain is a digital log file , Using encryption technology , Protect online transaction data . The idea of blockchain technology is 1991 It took shape in 2000 , The currency , It's the first application to put distributed public blockchain into practice . Blocks are digital archives of transactions , The establishment of the transaction requires the consent of the blockchain participants . Usually , Blocks contain things like price 、 action ( Buy 、 Sell out 、 Transfer, etc ) Transaction data like that , There's also a timestamp . Every deal ( Or a series of deals ) Create a block . Each newly added block contains the password hash of the previous block ( Now the hash is usually SHA-256). In this way , Each transaction block is encrypted and locked to the previous block .

If the blockchain is publicly distributed , Like bitcoin , Then each participant can verify any transaction in the blockchain . You may not be able to see the amount or value of money held by a participant , Unless the information is included in the transaction ; But you can see the value of the transaction between two participants , And can verify its effectiveness . By presenting a password that is difficult to forge but easy to verify by all participants , Any participant can prove his ownership of a specific blockchain account .

The mechanism of blockchain can use public key / Private key cryptography is an analogy , In this cryptosystem, each participant can use the private key to create the signature content , All other participants can use the associated public key , It's easy to verify the content of the signature .

Just as cloud computing has a public cloud 、 Private cloud and hybrid cloud , Blockchain also has Public chain The chain of private and Mixed chain Three models . You can create your own blockchain , Using other blockchains provided by a larger group with common interests , Or even participate in the global public chain , Like bitcoin . Although it's a relatively new feature , Private blockchains and public blockchains can still join each other .

From bitcoin to blockchain

Most people's knowledge of blockchain comes from bitcoin , The popular cryptocurrency is made by the nickname “ Nakamoto ” People who / The team , On 2008 Created in 2000 . Nakamoto did not invent the concept of blockchain , But he does validate for decentralized books and digital currency transactions , The concept of distributed blockchain is introduced . This concept solves the inherent problem of decentralized digital currency without trusted third party “ Double payment ” problem .

2008 year 10 month , Nakamoto is in metzdowd.com An article was posted on the encrypted mailing list of , Titled 《 The currency : Point to point e-cash system 》.2009 year , He generated the first block of the blockchain , Created software that anyone can download to mine bitcoin . Among the people who downloaded the software just a few days after the article was published , Someone quickly came up with 3 Bitcoin .

Although from the beginning , The future and ultimate value of bitcoin is reflected , But the first “ official ” transaction , Yes, it is 1 Ten thousand bitcoins bought value 20 Pizza for dollars . today , The value of bitcoin has grown dramatically ,12 month 12 The daily trading price hit 17428.42 The dollar's all-time high , But volatility is frequent and huge . Huge and rapid price increases , It's caused investors and financial companies CEO Your attention , Although not necessarily in the affirmative . Many investors will raise the price of bitcoin , Analogy to 17 Tulip bubble of Holland in the 21st century —— Some investors get rich overnight , And the skeptic can only watch his friends promote to the rich class .

The currency 、 Mining software and distributed network establishment , A series of newly generated bitcoins , Making the next bitcoin more and more difficult . therefore , In the past, a computer could produce bitcoin in a few hours , Now you need to aggregate thousands of specialized specific hardware “ The miners ” Computers form networks , It takes weeks to months to produce . today , The power used to generate bitcoin , It's comparable to the global total daily electricity consumption .

Not only does it take a lot of computing power to create bitcoin , The computing effort needed to create and validate bitcoin transactions cannot be underestimated , Although not in the same field . and , Each transaction increases the size of the blockchain —— Blockchain continues to grow over time ( Bitcoin's blockchain has surpassed 100GB), And must be generated and distributed to all participants to maintain effectiveness . Final , To 2140 year , At most 2100 Ten thousand bitcoin . The self induced scarcity of encryption , It's one of the driving forces behind the rocketing price of bitcoin .

Bitcoin may be a bubble , But blockchain is not

Investors and financial experts argue over the value of the currency , But no one questions the value and legitimacy of blockchain . The biggest companies in the world have formed teams , Sometimes it's a whole new Department , To focus on blockchain . You can create and use blockchains in the cloud or in private businesses .

Blockchain companies , See the future where almost every financial transaction is supported by blockchain . Blockchain enables very complex financial transactions to be resolved in seconds . One of the blockchain leaders of multinational banks said , On average, financing M & A transactions are 1 It's only three months before we can make a clear financial handover . Use blockchain , It can be done in a few seconds . Regulators should really think about the huge impetus blockchain has for improving the efficiency of complex transactions , Free people and capital , Into something more productive and constructive .

Almost every financial transaction intensive industry , They are eager to find ways to implement blockchain in their respective companies and industries . Just name a few industries , Blockchain is a hot topic in the industry . Cloud giants in the computer industry , Like Microsoft and Amazon , Now there are countless blockchain Services .

Search the Internet for blockchain , You will be 2016 Ten million information links and services poured out after ten years . Bitcoin may be a bubble , But blockchains are emerging , And will continue to develop .

Hacking into bitcoin and blockchain

In the early , A lot of bitcoin and blockchain enthusiasts want to know , Whether the inherent encryption nature of the two is enough to resist continuous hacker attacks . It didn't take long for the answer to emerge . Just like all the valuable things relying on computers , Bitcoin and other cryptocurrencies , And blockchain , Under constant attack . Hundreds of millions of dollars were stolen , People are constantly being cheated , The blockchain has been looted . Here are some examples of bitcoin and blockchain being hacked .

1. Bitcoin mining malware

Every bitcoin dug up , Make bitcoin more difficult to create in the future . Need a lot of power operation and cooling professional “ The miners ” Computer . Compared to the Tek miners , Electricity is the number one operating cost . therefore , A lot of bitcoin miners “ To borrow ” Resources to mine bitcoin , Or in their employer's industry , Or spread bitcoin mining malware . Now , Many large malware botnets are used to mine bitcoin . Although the original intention is not bad to the extreme , But it's still about computers or devices ( Usually hijacking online camera devices and routers ) Unauthorized use of , And cost the victim money . These malware also slow down hijacked computers . Stop bitcoin mining like any other malware program .

2. Stolen value storage

Cryptocurrency usually stores its value in a file called a wallet . Wallets can be invaded 、 Tampering 、 Stealing and transferring , Just like any other store of value on a computer . To make matters worse , People often forget their protective passwords /PIN code , Or lose the hard disk with the value of storage , And this often means that the value store will never be found again . Blackmail software can cause this problem . If it's a normal bank account , You can also use another computer to access online banking , There's no change in the money . But cryptocurrency wallets ? You are being paranoid. . To lose is to lose , If you can't open it, you can't open it , No one can help you recover .

Most experts recommend keeping cryptocurrency in an offline wallet , Protect against malware or hackers . But it also makes it hard to use the value . Offline features can take days to use and update value . If you're using an online wallet , Protect it with multi factor authentication if possible .

3. Transfer Trojan

Cryptocurrency Trojan will monitor your computer , Wait for something that looks like cryptocurrency account format to appear . Just find the target , The Trojan will replace the account you are going to pass in the value with your own account . Unless you're particularly sensitive to the switch , Otherwise, when you press “ send out ” Button time , It's all over .

4. Implementation flaws

“ Theoretically , There is no difference between theory and practice . actually , That's the difference .” No one knows who said it first , But first published in a Book , Is in 1986 Walter J. Published by savage 《Pascal: The art and science of programming 》 in .

As with any encryption implementation , Encryption algorithms are always much more reasonable and sensible than the programs that implement them . Basically , Blockchain comes with any encryption solution, which will have loopholes or defects . Programming vulnerability or lack of good private key security ( Or bitcoin wallets ), Can make the whole thing collapse . Although this is not so obvious , But before using cryptocurrency or participating in blockchain projects , Make sure the software developer applies the security development lifecycle (SDL) Process to minimize vulnerabilities .

It is not uncommon for hackers to tamper with cryptocurrency software to steal value . In a recent case , The hacker made a programming mistake , Not only did they not steal any value , And it's destroying everyone's wallet , Recovery incompetence . It's typical to do harm to others but not to yourself .

5. Known plaintext grabbing attacks

Good encryption can make ciphertext look like random random random code . Theoretically , Encryption attackers should not be able to analyze the original plaintext . However , Blockchain Technology , The block format is well known , Or it's easy to analyze . Specific letters 、 Characters or numbers always exist in a fixed position in each block . This makes it easy for an encryption attacker to extract information from every block protected by encryption “ Grab ” Part of the text indicates . in addition , Each block is associated with the previous block . therefore , The overall protection of the underlying encryption password is weakened . If the password is not weak , That's not a big problem , But this does give the attacker an advantage .

6. weak SHA-256?

A lot of security experts want to know ,SHA-256, That is, with its shorter predecessor SHA-1 A secure hash algorithm with the same mathematical weakness , Whether it's bitcoin or blockchain ( Both usually use SHA-256) One of my concerns . The answer is : Not yet .SHA-256 Strong enough for the foreseeable future . what's more , Given that most financial transactions and HTTPS The deal is made by SHA-256 Protect , If someone breaks the algorithm , It's not just bitcoin and blockchain that we have to worry about . even so , If you plan on cryptocurrency or blockchain , Let's start planning first “ Encryption agility ” Well —— The ability to retain the support program and only replace the password .

7. Hacked websites

The most common hacking around bitcoin , It is also a hacker activity that can be applied to any blockchain project , The central website that controls bitcoin or blockchain has been hacked . This kind of activity is really too common , It happened last week , Let hackers make money 7000 $10000 bitcoin . Too many sites managing hundreds of millions of dollars of cryptocurrency have been successfully hacked . Once the control website is hacked , The value of bitcoin that people create , Often dissipated in the network . It's a good way to back up the value offline .

Some of the biggest hacking incidents , They're all unscrupulous hackers who run away with tens of millions of ill gotten gains . If you do business with cryptocurrency sites , Make sure the site is secure and trustworthy . The FDIC won't pay for the disappearance of your savings , At least not now .

8. Large public blockchains are safer

Understand a concept of blockchain security , Public distributed blockchains are more secure than private ones . Want to hack the blockchain , The attacker has to control more than 50% Participants or blocks of , And this action is faster than creating new blocks .

therefore , Large public blockchains are inherently safer than small private ones . Control of small blockchains will be faster and easier , Especially in all the relevant “ Secret ” All stored in one place or company . in fact , Many security experts are questioning the need for a single company's blockchain . They think that , The advantages of blockchain , Only when distributed across a single security boundary . However , You're still going to see a lot of private small blockchains , Because blockchain has the potential to solve complex financial transactions in seconds , It's also because small blockchains can become large hybrid / Components of the public blockchain .

Every security practitioner should understand blockchain , And the significance of blockchain to its current and future career . Even if the blockchain is based on a very secure password , It's going to be blackened like anything else .


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