Introduction
Blockchain enables security hardening through various mechanisms, which include cryptography-based cryptography, consensus mechanisms, mathematical models, etc. and is the underlying architecture of most digital currency systems.
The use of blockchain technology is also particularly important in some industries where data tamperability and security are very important. Examples include recording and tracking charitable donations, medical databases, and supply chain management.
Therefore, it is important to understand how the underlying concepts and mechanisms of these innovative systems provide strong protection for blockchain.
Cryptography Provides the Foundation for Encryption
Blockchain relies heavily on a series of cryptographic techniques to secure data. The cryptographic hash function is the key to this technology. Hashing is a computational process, and a hash algorithm is an algorithm that can input data of any size and output a predictable and fixed-size hash.In a hashing algorithm, if the input changes, the output will be completely different. As long as the input remains the same, the output hash will always be the same, no matter how many times the hash function is run.
And in a blockchain, these output values (i.e., hashes) are the unique identifiers of the data blocks. The hash of each block is generated relative to the hash of the previous block, which can link numerous independent blocks together to form the reason for the blockchain. In addition, the block hash is determined by the data contained in that block, which means that any changes made to the data will change the block hash value. Thus, the data of that block and the hash of the previous block together determine the hash of each block. These hash identifiers play an important role in ensuring that the blockchain is secure and tamper-proof.
Hash functions are also used in consensus mechanisms that validate transactions. For example, on the Bitcoin blockchain, the proof-of-work (PoW) algorithm employs a hash function called SHA-256, which takes the input data and computes it to output a hash that is 256 bits long, or 64 characters long.
In addition to providing protection for transaction records in distributed ledgers, cryptography can also play an important role in the security of wallets that store digital currencies. Pairs of public and private keys, for example, allow users to receive and send digital currencies by using asymmetric or public key cryptography, respectively. The private keys are used to generate the electronic signatures required by the exchange, which can verify the ownership of the sent currency.
Consensus Mechanisms Ensure Blockchain Security
The consensus mechanism, or consensus algorithm, is an important mechanism to ensure that all participants in the network agree on the state of the ledger. This mechanism also ensures that no single entity can control the network and can effectively prevent malicious acts from occurring, such as tampering with transaction data, stealing funds, etc.
Through specific consensus mechanisms and algorithms, even though blockchain is a public ledger, it can still ensure user privacy to a certain extent. These consensus mechanisms and algorithms further ensure that the data stored on the blockchain is secure and can not be tampered with.
Possible Attacks Faced
Although blockchain technology is theoretically secure, this does not mean that it is completely immune to hacking and security breaches. Typically hackers and fraudsters threaten blockchain security in four main ways: phishing, Sybil attacks, 51% attacks and routing attacks.
Phishing is a very common type of fraud that attempts to obtain user credentials. Fraudsters send carefully crafted emails to blockchain users that often mimic the design and name of some trusted, well-known platform. The emails will use fake hyperlinks to ask users to provide their credentials. Once access to the user's credentials and other sensitive information is gained, it can lead to the leakage of private keys, which in turn can lead to losses for the user and the blockchain network.
A Sybil attack is where hackers create and use many fake network identities to flood the network and bring down the system. By leveraging the open, free-to-participate nature of blockchain, some hackers can create a large number of virtual identities in bulk to carry out attacks.
A 51% attack means having more than 50% of the computing power means having control of the ledger and the ability to manipulate the blockchain network. Mining usually requires a large amount of computing power distributed among different miner nodes. However, if a miner or group of miners can pool enough resources, they can gain access to more than 50% of the blockchain network's mining computing power.
Routing attacks refer to the process of transmitting data to an Internet service provider where hackers can intercept the data. In such an attack, the threat is usually invisible to blockchain participants, so everything looks normal. Behind the scenes, however, fraudsters have extracted confidential data or cryptocurrency.
How to Prevent and Protect Blockchain Security
For users who frequently use wallets to invoke smart contracts, they often authorize different functions of their wallets, which can expose assets to risk if not carefully differentiated. As a user, it is good to regularly check the condition of your wallet or use a more secure cold wallet.
For operators, they need to regularly upgrade their code and actively maintain their operational systems to avoid risky vulnerabilities that could lead to exploitation or attack.
Summary
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The security of blockchain is ensured by the consensus mechanism from malicious attacks and from tampering of transaction data and theft of assets.
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Regular maintenance, upgrades, and checking wallet node permissions all help to protect asset security.
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Crypto investment involves significant risks. Please proceed with caution. The course shall not be considered investment or financial advice.