Blockchain technology is becoming more popular as people discover its use cases.
According to a study, out of 100 largest companies in the world, 81 are pursuing blockchain related solutions.
With the growing popularity, concerns arise over the security of blockchain.
Source : IBM
Integrity of Transaction
During transition, blockchain transactions content shouldn't be changed. That means, the integrity of the transaction should remain unharmed.
Preventing Tamper
Blockchain must prevent tampering with the objects within an active transaction and historical data already stored in the blocks, in order to become tamper proof.
Bitcoin blockchain discourages tampering as it would result in the automatic exclusion from the network.
A node operator who is responsible for approving of transactions and adding new blocks is discouraged from tampering the records as it will be discovered easily.
The node operator stops receiving mining rewards if a node becomes inactive.
Consistency
A blockchain's ledger should be consistent as blockchain is a distributed network and nodes should be updated simultaneously every time a new block is added.
Accessing Blockchain Data
Another critical aspect of security is the access to blockchain data.
For a blockchain to work properly, a node or a user must be able to view the records saved on the ledger any time.
User Privacy
A term pseudo anonymity which means that only addresses are revealed, not the users behind the addresses.
This help in protecting user's privacy and allows them perform transactions without revealing their identity.
Resistance to attacks
It is important that a security system protects ledger contents and transactions against hostile attacks.