  We have entered an era where the importance of decentralized solutions has
become more obvious. Blockchain technology and its derivatives are distributed
ledger technologies that keep the registry of data between peers of a network.
This ledger is secured within a successive over looping cryptographic chain.
The accomplishment of the Bitcoin cryptocurrency proved that blockchain
technology and its derivatives could be used to eliminate intermediaries and
provide security for cyberspace. However, there are some challenges in the
implementation of blockchain technology. This chapter first explains the
concept of blockchain technology and the data that we can store therein. The
main advantage of blockchain is the security services that it provides. This
section continues by describing these services.. The challenges of blockchain;
blockchain anomalies, energy consumption, speed, scalability, interoperability,
privacy and cryptology in the age of quantum computing are described. Selected
solutions for these challenges are given. Remarkable derivatives of blockchain,
which use different solutions (directed acyclic graph, distributed hash table,
gossip consensus protocol) to solve some of these challenges are described.
Then the data storage in blockchain and evolving data solutions are explained.
The comparison of decentralized solutions with the lcentralized database
systems is given. A multi-platform interoperable scalable architecture (MPISA)
is proposed. In the conclusion we include the evolution assumptions of data
storage in a decentralized world.
