A Data Preservation Method Based on Blockchain and Multidimensional Hash for Digital Forensics

Table 1

Comparison of some blockchain architectures.

Blockchain	Bitcoin	Ethereum	Ripple	Hyperledger
Architecture	Electronic encrypted currency system	Electronic encrypted currency system	Electronic currency settlement system applied for payment	Blockchain platform for commercial application
Type	Public blockchain	Public blockchain	Consortium blockchain	Consortium blockchain
Consensus algorithm	Proof of work (PoW)	Proof of work (PoW)	Ripple prove of consensus algorithm (RPCA)	Practical byzantine fault tolerance [21] (PBFT)
Fault tolerance	49%	49%	(n-1)/5	(n-1)/3
Smart contract [22]	Not supported	Supported	Not supported	Supported
Block generation time	10 minutes	15 seconds	3–6 seconds	3–6 seconds
New node and block synchronization	Adding nodes dynamically not supported and synchronization takes long	Adding nodes dynamically not supported	Adding nodes dynamically supported	Nodes cannot be added dynamically and breakpoint recovery
Privacy	Anonymity, unable to audit	Anonymity, unable to audit	Support privacy of individual transaction	Member service management, strong identity authentication, auditable
Other	—	Introduce turing-complete smart contract language	Introduce UNL trust nodes list	Pluggable consensus algorithm framework, electronic currency