Towards Verifiable Mutability for Blockchains
This addresses privacy and legal compliance issues in blockchain technology, representing an incremental improvement.
The paper tackles the problem of blockchain immutability by proposing a mutable blockchain structure that allows removal of certain blocks while preserving verifiability, applicable to both permissioned and permissionless blockchains.
Due to their immutable log of information, blockchains can be considered as a transparency-enhancing technology. The immutability, however, also introduces threats and challenges with respect to privacy laws and illegal content. Introducing a certain degree of mutability, which enables the possibility to store and remove information, can therefore increase the opportunities for blockchains. In this paper, we present a concept for a mutable blockchain structure. Our approach enables the removal of certain blocks, while maintaining the blockchain's verifiability property. Since our concept is agnostic to any consensus algorithms, it can be implemented with permissioned and permissionless blockchains.