Segment Blockchain: A Size Reduced Storage Mechanism for Blockchain

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 <italic>PoW</italic> as a membership threshold to limit the number of nodes taken by an Adversary—the Adversary can only gain at most <inline-formula> <tex-math notation="LaTeX">$n/2$ </tex-math></inline-formula> of nodes in a network of <inline-formula> <tex-math notation="LaTeX">$n$ </tex-math></inline-formula> 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 <inline-formula> <tex-math notation="LaTeX">$(AD/n)^{m}$ </tex-math></inline-formula> failure probability when the Adversary has no more than <inline-formula> <tex-math notation="LaTeX">$AD$ </tex-math></inline-formula> number of nodes and every segment is stored by <inline-formula> <tex-math notation="LaTeX">$m$ </tex-math></inline-formula> 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.