is blockchain secure 
blockchain technology achieves decentralized security and trust in several ways to begin with new blocks are always stored linearly and chronologically that is they are always added to the end of the blockchain after a block has been added to the end of the blockchain previous blocks cannot be changed a change in any data changes the hash of the block it was in because each block contains the previous block s hash a change in one would change the following blocks the network would generally reject an altered block because the hashes would not match however this can be accomplished on smaller blockchain networks not all blockchains are 100 impenetrable they are distributed ledgers that use code to create the security level they have become known for if there are vulnerabilities in the coding they can be exploited a new and smaller chain might be susceptible to this kind of attack but the attacker would need at least half of the computational power of the network called a 51 attack on the bitcoin and other larger blockchains this is nearly impossible by the time the hacker takes any action the network is likely to have moved past the blocks they were trying to alter this is because the rate at which these networks hash is exceptionally fast the bitcoin network hashed at a rate of 566 657 exahashes per second 18 zeros between may and june 2024 1the ethereum blockchain is not likely to be hacked either the attackers would need to control more than half of the blockchain s staked ether between april and june 2024 more than 32 million eth was staked by more than one million validators 2 an attacker or group would need to own more than half of the validators about 16 4 million eth and be randomly selected to validate blocks enough times to get their blocks implemented bitcoin vs blockchainblockchain technology was first outlined in 1991 by stuart haber and w scott stornetta two researchers who wanted to implement a system where document timestamps could not be tampered with 3 but it wasn t until almost two decades later with the launch of bitcoin in january 2009 that blockchain had its first real world application the bitcoin protocol is built on a blockchain in a research paper introducing the digital currency bitcoin s pseudonymous creator satoshi nakamoto referred to it as a new electronic cash system that s fully peer to peer with no trusted third party 4the key thing to understand is that bitcoin uses blockchain as a means to transparently record a ledger of payments or other transactions between parties blockchain can be used to immutably record any number of data points this could be in the form of transactions votes in an election product inventories state identifications deeds to homes and much more currently tens of thousands of projects are looking to implement blockchains in various ways to help society other than just recording transactions for example as a way to vote securely in democratic elections the nature of blockchain s immutability means that fraudulent voting would become far more difficult for example a voting system could work such that each country s citizens would be issued a single cryptocurrency or token each candidate could then be given a specific wallet address and the voters would send their token or crypto to the address of whichever candidate they wish to vote for the transparent and traceable nature of blockchain would eliminate the need for human vote counting and the ability of bad actors to tamper with physical ballots blockchain vs banksblockchains have been heralded as a disruptive force in the finance sector especially with the functions of payments and banking however banks and decentralized blockchains are vastly different to see how a bank differs from blockchain let s compare the banking system to bitcoin s blockchain implementation 