Search code examples
blockchaindata-recovery

recover lost data in block-chain

i'm new to block-chain and a question is blowing my mind.

if some body change data in a block of block-chain, so the hash will change and the next block will understand because it has previous block hash.

So how to recover those lost data which were changed? is there any idea or some solution.

Solution

  • For an example, if we take a simple Blockchain where the Blocks will keep data such as

    • Transfer Amount
    • Transfer From
    • Transfer To
    • Previous block hash
    • current block hash

    Check this Image : Simple Blockchain Example enter image description here

    Lets say, If some one was able to change the Last Block and manipulate the data, it is really unlikely that he is able to add this change in to the block chain (check this question and its answers to understand why its unlikely that this can be achieved : This Question : Why is Blockchain so Secure) The manipulator will need enormous computing power and the majority 51% of the nodes consent

    So since this can not be done, the data will not be changed. If a new block is added to the blockchain, that will be in the block chain and never be changed.