Security feature in blockchain
There is no centralized “official” block copy that exists. If any person wants to change its own database copy, it will be reflected until it is verified by the verifier. This reduces the chances of hacking or security breaches.
Blockchain uses public key and private for encryption. Private key is known only to the user and it is not stored anywhere. During transaction, only scriptpubkey is shared. Scriptpubkey contains a public key and network address in an encrypted format. So the sender does not know about public key and network address making it a highly secured way of transaction compared to other technologies. Following diagram depicts the transaction flow.