FGUGChain

Abstract

The emerging blockchain technology is the brainchild of Nakamoto, who invented bitcoin in late 2000s. The underlying structure of bitcoin is made up of blockchain, which is an open ledger of blocks linked by the hash values of subsequent blocks. Every action that happens on the blockchain is reflected on each node involved, and the data and transactions are stored on every node. We can say that blockchains provide decentralized solutions for a variety of applications, ensuring only honest parties to be part of the system at the cost of privacy. Blockchain allows mutually distrusting parties to transact cryptocurrency or involve in any other application without the involvement of trusted third party. Transparency is maintained on every level and on each transaction, leaving the data exposed to all the parties involved. In short, we can say that blockchain provides an excellent decentralized solution without privacy. On the other hand, secure computation provides privacy of data on a distributed environment without a third party, but the parties involved in computation have to be monitored carefully to ensure their honesty. Combining both the technologies leads to “ blockchain with privacy” . In recent years, research is happening into combining blockchain concepts with secure computation. While introducing data privacy to blockchain with the help of secure computation, the complexity of application increases. In this chapter, let us see how to minimize the complexity while generating distributed decentralized applications with privacy by incorporating optimized protocols for secure computation. The FGUGChain framework presented in this chapter gives a guideline for generating blockchain applications with privacy. Throughout this chapter, the term blockchain is used in the sense of public blockchain as it preserves decentralization concept, whereas the private blockchain tend to move toward centralized nature.