Blockchain is a relatively new technology in the modern world. Unlike conventional centralized systems, blockchain is distributed and decentralized. This means that instead of having a single administrator, all users can play a role in managing the network. The features of blockchain, along with its structure, simultaneously create its security. Some of the features of blockchain include: 

All information on the blockchain is digital, eliminating the need for paper documents.

Blockchain symbolizes a digital revolution that began with cryptocurrencies like Bitcoin, but this technology can have multiple applications beyond just digital currencies.

Distributed blockchain serves as a public ledger among all network members in a distributed ledger technology (DLT) and transaction control and validation are performed by these members without the need for access to a centralized authority.

Due to the functioning of this system, the possibility of any errors arising is eliminated. If a node (participant in the network) fails to perform its task correctly, it will not disrupt the functioning of other nodes, and each will continue to perform its task correctly.

Immutability: All blockchain-based transactions are immutable. Each transaction is well encrypted with its date, time, participants, and the hash of the previous block. Reversing or deleting a transaction in the blockchain is almost impossible.

The blocks created as a result of a transaction on the blockchain are never deleted, changed, or replicated. This ensures a high level of security.

Each block in the blockchain maintains information about its preceding block, forming a chain that contains all transactions executed on the network. New transactions will be recorded in continuation of this chain.

The consensus mechanism for a transaction is executed on the blockchain only when at least 51% of the participants confirm it. According to consensus algorithms, no invalid or unstable transaction will be created or sustained in the blockchain. The only way to create a transaction is to gain the trust and confirmation of the majority of network participants.

Different consensus algorithms are used to secure the blockchain, but Proof of Work (PoW) and Proof of Stake (PoS) are currently the most popular.

Blockchain digital signatures confirm the value of a transaction solely through digital signatures associated with the public key (an encrypted code recognized by everyone on the network). Private keys are defined only for designated owners and function similarly to a password. This is one of the most important methods to prevent fraud and theft on the network.

The data on the blockchain is stable, complete, perpetual, accurate, and largely accessible. No old data can be deleted from the blockchain. 

These features collectively contribute to the security of the blockchain, making it an extremely robust and trustworthy technology for various applications beyond just financial transactions.

Which features ensure the security of blockchain?

The point we intend to address in the blockchain security article is that nothing is absolutely secure. However, blockchain has features that reassure users; features like Tamper-proof, Immutability, and Public nature. Blockchain assists in recording any type of asset transferred between two parties. Many aspects supported by blockchain security play a significant role in ensuring clarity, transparency, confidentiality, and protection against theft and fraud. The following features are the most important indicators of blockchain security.

Ledger or Distributed Ledger 

Technology (DLT) records all transactions of a blockchain in itself. This ledger is a chain of blocks, and the information stored in it will be immutable. Once a transaction is recorded in it, its information is also recorded in all other nodes across the world.

blockchain

consists of a large number of blocks. Each of these blocks has the value of the hash of its previous block, forming a chain. This blockchain feature greatly assists in data protection.

Maintaining privacy while simultaneously being transparent

is another feature in blockchain security. Users of a ledger can only view confirmed transactions. This feature is considered one of the most important indicators of security in blockchain. It means that a user cannot identify the identities of other users by examining the ledger and can only observe the transaction process.

Encryption

in blockchain security encrypts data using various encryption algorithms, preventing anyone from tampering with or altering the data without the encryption key. These algorithms are different for each cryptocurrency. Encryption algorithms are programmed to provide a fixed-size output for any input, known as hashing. The output obtained, consisting of a string of numbers and letters, is also called a "hash." 

Smart contracts

have functionality similar to paper contracts and are written in computer code. Each of these smart contracts in blockchains has rules that groups agree upon. When the agreement related to smart contracts is defined and coded, there will be no need for intermediaries anymore, and all operations will be performed automatically and without individuals, as stated in the contract. It should be noted that no smart contract will be executed without network consensus. 

How does blockchain ensure data security?

 Blockchainis a chain of digital blocks containing transaction records. Each block is connected to all blocks before and after it. This makes tampering with block data difficult because a hacker would have to change the data of the desired block and the blocks associated with it to prevent detection. The records in blockchain are securely encrypted. Network participants have their private keys assigned to the transactions they make, acting as a personal digital signature. If data changes, its signature becomes invalid, and the network immediately detects that something has happened. Since blockchains are not located in a central location, they are less vulnerable, and they cannot be altered from a single computer device. To access a specific blockchain, attack and change all block data simultaneously, requires massive computational power. Today, this task is also expensive. As a result, blockchains have desirable features that greatly assist in securing block data.

 Is hacking blockchain possible? 

Yes! But it's very difficult and costly. Consensus algorithms and network mechanisms are usually designed to rely on users' honest activities. But you should know that the more widespread a blockchain becomes and the more users it has, the harder and more expensive it will be to hack. Even if hacking Bitcoin was once possible, it is now highly unlikely. This point is almost true for all blockchains. 

Blockchain is the safest technology in the world. As we said, nothing in this world is 100% secure, but blockchain technology is one of the safest technologies in the world. Blockchain security is strongly guaranteed due to its decentralization, consensus mechanism, and encryption. When these three features are combined and applied in an emerging technology called blockchain, the task becomes increasingly difficult for hackers and fraudsters.