time.
• This is annoying. As this deals with higher transaction fee and deal with transaction uncertainty.

It’s hard to scale. As we don’t want to store the data directly in block chain as there is thing called block chain bloating so we want to have a pointer which is pointing to a data living in a distributed hash table.

Fees

• Average transaction fee for transaction is in bitcoin network is $1. It might not be too much for high transactions but for the transactions dealing with microtransaction, it means a lot!
• Solutions include increasing block size limit, lightning network, central servers for off chain transaction, sidechains and treechains.

Lots of Computing Power required

• Mining is somewhat centralized in blockchain by giant mining pools.
• Transaction speed declines as the network increases in size as more transactions compete for the limited block spaces.

• It will take more and more computing power to mine the same amount of bitcoin.

Vulnerable to Quantum attack

• Bitcoin and other proof of work based blockchains are susceptible to being broken by a powerful quantum computer.

There is another technology which has evolved called “IOTA”.

IOTA ARCHITECTURE

IOTA USES BLOCKDAG

• IOTA is not an acronym for Internet of Things, IOTA just mean something very small. Block chains are sequential chains where blocks are added in regular intervals.
• The tangle a DAG (Directed Acyclic Graph) is able to achieve high transaction throughput and no transaction fees on transactions.
• As it grows and more participants make transactions, the overall system becomes more secure and faster, with confirmation times/ transaction finality going down.
• But look it’s still uses distributed database, it’s still a P2P network and it still relies on a consensus and validation mechanism.
• The more the nodes, the faster the transaction speed will be.

Green Blocks: Transactions on which consensus was achieved.