Abstract
The exponential growth of the blockchain size has become a major contributing factor that hinders the decentralisation of blockchain and its potential implementations in data-heavy applications. In this paper, we propose segment blockchain, an approach that segmentises blockchain and enables nodes to only store a copy of one blockchain segment. We use PoW as a membership threshold to limit the number of nodes taken by an Adversary-the Adversary can only gain at most n/2 of nodes in a network of n nodes when it has 50% of the calculation power in the system (the Nakamoto blockchain security threshold). A segment blockchain system fails when an Adversary stores all copies of a segment, because the Adversary can then leave the system, causing a permanent loss of the segment. We theoretically prove that segment blockchain can sustain a (AD/n) m failure probability when the Adversary has no more than AD number of nodes and every segment is stored by m number of nodes. The storage requirement is mostly shrunken compared to the traditional design and therefore making the blockchain more suitable for data-heavy applications.
I. INTRODUCTION
In the anonymous and autonomous society like a blockchain system, every record should be re-derivable. This feature forms the essential trust of the blockchain, and secures the blockchain; thus, keeping every history transaction is critical. However, the size of the Nakamoto blockchain (Bitcoin [1]) has grown from the ground to over 226 Gbytes in the past ten years from January 2009 to June 2019; the size doubled since the February 2017 (at slightly over 100 Gbytes) [2]. If the exponential growth to be continued, we are expecting 1.5 to 1.6 T Bytes in Jan 2021, 3 to 3.2 T Bytes in Jan 2022. Parallel to the growth of blockchain size, the storage cost of being a full node (the node which stores all the blocks of the mainchain) in the Bitcoin network is also grown in exponential.
VI. CONCLUSION
In this paper, we showed an approach to reduce the storage requirement of the blockchain system while keeping the decentralisation without compromising the security of the blockchain. The data analyses proved that segment blockchain largely reduced the data requirement compared to Nakamoto blockchain. Thus, it is of more advantage to using segment blockchain to power
