Immutability is one of the fundamental ethos of the blockchain universe. It promises users that all transactions will be recorded on a public ledger that cannot be changed forever. However, this simple idea is more nuanced in the world of decentralized consensus and cryptography. While it is practically impossible to change history on a major network, the theoretical possibility remains tied to the power of miners.
How Mining Protects the Past
Miners are responsible for solving mathematical puzzles needed to mine new blocks on the blockchain. Miners compete to do this under a Proof of Work (PoW) system. This process generates a linear, chronological string of data. Each new block contains a “hash” (a unique digital fingerprint) of the previous block, effectively locking it into place.
To change a transaction in a past block, a miner would have to not only re-mine that specific block but also every subsequent block that has been added since then. This is because changing one piece of data changes the hash, which breaks the link to all future blocks.
The 51% Attack: Rewriting the Ledger
Never say never. While miners and validators can’t directly steal your funds, it’s possible for a malicious majority (controlling more than 51% of the network’s hash power or staked tokens) to perform a “double-spend” attack. This kind of attack enables a miner to essentially fake sending you funds in exchange for goods or services or another token and use their superior computing power to secretly build a longer chain that excludes that transaction.
Frequently Asked Questions
Can Miners or Validators Steal User Funds?
No, they can only censor or reorder transactions, not access funds without private keys.
How Do Blockchains Recover From Major Failures?
Through community coordination, hard forks, or social consensus to restore valid state.
Disclaimer: BFM Times acts as a source of information for knowledge purposes and does not claim to be a financial advisor. Kindly consult your financial advisor before investing.
