CODEWITHSUNDEEP
blockchaindata-recovery
EBIRAM
EBIRAM

Reputation: 3

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.

Upvotes: 0

Views: 448

Answers (3)

Shyam
Shyam

Reputation: 192

Precisely Data cannot be altered in Blockchain, that is why it is more favourable for systems, which want to keep transparency

Upvotes: 0

Thilina Chandrathilaka
Thilina Chandrathilaka

Reputation: 26

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.

Upvotes: 0

arjunkhera
arjunkhera

Reputation: 979

That is the whole thing about blockchain, that you do not maintain a single copy of the ledger. A blockchain is a decentralised distributed ledger. Hence every node stores a copy of the ledger.

If someone maliciously does modify the ledger, the affected node can check from other honest nodes and revert back to the original state. For an attack to be carried out successfully, it must result in modification of at-least a majority of the nodes maintaining the ledger.

Upvotes: 1

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