Is Blockchain Really Immutable? Debunking the Myth

Whenever we talk about blockchain, immutability is the next thing that comes up. There are different views on the topic, but when it comes down to it, everyone is looking for an answer to a single question – are blockchain and Bitcoin immutable? The short answer is – Yes, blockchains and Bitcoins cannot be changed. The long answer is that you still need to know the reasons behind that answer in order to understand the implications.

Before diving into the topic, it is important to understand the basics of blockchain. However, we will not get into core technical details, since it is a topic in itself. So, what is blockchain? Many people interchangeably use the term blockchain and Bitcoin, but they are not the same. Blockchain is a concept, an idea. Bitcoin is the first and major implementation of that idea. There can be other different implementations on top of blockchain which are nowhere related to Bitcoin. In fact, there has been decent progress in other areas such as smart contracts, inter-bank settlements, etc. which are more interesting than Bitcoin.

Blockchain is essentially a distributed ledger. In contrast to traditional paradigms in which a central trusted authority controls everything, blockchain creates a network with no single point of power. There is no need to "trust" anyone because the system itself makes taking control very hard. This decentralization is what gives it such strength and attraction to the general public.

Bitcoin is a crypto-currency based on blockchain that is not regulated by anyone. The transactions are instantaneous and there is a minor fee associated with a transaction, which makes it very popular for worldwide payments. However, there is no intrinsic value of the currency, since it is not backed by anything. Its value is dependent purely on how much people are willing to pay and directly correlates with the trust people have in the system. That’s why you see the price of Bitcoin go down whenever a negative news associated with the blockchain comes out.

Bitcoin transactions, occurring globally, are stored in a decentralized manner across the network, ensuring multiple copies of the data are dispersed. Essentially, this forms a connected chain of blocks. However, if these blocks were susceptible to modifications, it would present an opportunity for malicious individuals to manipulate the transaction history, enabling them to amass significant wealth by altering the records. Consequently, the immutability of the blocks holds paramount significance. Now, let us delve into the specifics:

What makes a blockchain network immutable?

Immutability is described as a blockchain ledger's ability to remain immutable, unmodified, and remembered. Each information block, such as facts or transaction details, is carried out using a cryptographic concept or a hash value. This hash value now contains an alphanumeric string created by each block separately. Each block has a hash value or digital signature that is unique to it and the preceding one. As a result, the blocks are retrospectively connected and unyielding. The blockchain technology feature assures that no one can interfere with the system or modify the data that has already been saved in the league.

It understands that blockchain is dispersed, and that decentralization is critical. A decision is taken here among the several storage locations for a copy of the data. This consensus ensures that the uniqueness of data is properly maintained. Immutability is without a doubt one of the most notable aspects of blockchain technology, and it also highlights the finest use cases for smart contracts that may be applied. The notion has the potential to reshape the entire data auditing process, making it much more efficient and cost-effective while also increasing data trust and integrity.

How to Achieve Immutability?

Cryptographic hashes are one of the main aspects that make blockchain immutable, which is why blockchain is immutable. The primary benefit of hash is that it cannot be reverse-engineered. That is why it is so well-liked. SHA-256, or Secure Hash Algorithm 256, is the most widely used hash algorithm.

The content of the block header is equivalent to strings of random characters and integers. For example, the previous hash is generally 32 bytes long and comprises four sets of eight-bit letters. When you divide 256 by 32, you get the original 256 bits.

The Merkle root is the fundamental component of the data structure. It indicates that no transactions are modified throughout the network. It represents a breakdown of each transaction. Furthermore, the timestamp indicates when the transaction was completed and sequentially arranges transactions. The nonce is the number that is increased during hashing to solve a certain block. It is a collection of decimal integers in polygon networks.

Hashing is the process of passing input through a cryptographic algorithm to produce an output. Every block in the blockchain is linked together via a cryptographic and hashing process. A normal public blockchain rule can only be broken by a hard fork, which generates a new chain that is incompatible with the older one. Keep in mind that hashing cannot be done.

Because the method is a subset of the parameters that connect all network blocks, it is immutable. These blocks are secured progressively, and no changes are permitted. If the data or input on the block is changed, the existing block will detach from all previous blocks. Thus, a hostile attacker or user wishing to change blockchain data must edit all blocks before the present block, which is a challenging process.

Threats to Blockchain’s Immutability

Consider blockchain networks that support transactions like the Bitcoin blockchain or a blockchain underlying a cryptocurrency. These networks can translate to being a double spending attack.

This decentralized technology is devoid of a single entity accessing a particular network’s strings. But, if data miners work in a group and gather most of the hashing power, blockchain immutability can pose a risk. Presently, it is easy to deal with such an attack in polygon networks owing to the ability to rent out mining capacity and growth in the mining marketplaces.

The same may be challenging and expensive to perform in large blockchain networks, specifically those running via the proof-of-work consensus protocol. The reason is it needs huge hashing power in crypto networks. Blockchain startups and smaller coins are at risk, as demonstrated by the double spending attacks conducted on Litecoin Cash, Bitcoin Gold, Monacoin, etc.

The attackers could reverse high-value transactions and spend the corresponding amounts for a second-time usage. This was possible by adapting the transaction data that was expected to be immutable in a permissioned blockchain.

Conclusion

This word ‘immutable’ is utilized to indicate something which can never be adjusted or changed. When a blockchain exchange has gotten an adequate degree of approval, some cryptography guarantees that it can never be supplanted or turned around. This imprints blockchains as unique in relation to standard records or data sets, in which data can be altered and erased freely.