Base

Is blockchain secure?

   Once a block is added to the end of the blockchain, it is very difficult to go back and change the content of the block.    Because each block contains its own hash and the hash of the block before it.    Hash codes are created by a mathematical function (hash function).

Once a block is added to the end of the blockchain, it becomes extremely challenging to alter the contents of that block or any preceding blocks. This is because each block in the blockchain contains its own unique cryptographic hash, which is generated by a mathematical function known as a hash function.