Permissioned Distributed Ledgers for Land Transactions; A Case Study

摘要

Considering the inefficiency and ineffectiveness of the current manual land registration systems being practiced in Sri Lanka and the emergence of the concept of blockchain based land registries as a successful replacement for badly kept, mismanaged and/or corrupt land registries from around the world, this research proposes and evaluates the applicability of a permissioned distributed land ledger solution for Sri Lanka. The final solution presents optimal content for the ledger (extracted from the current folio), preserves current land transactions, has reassigned duties to state validators and has got away with the folio system while ensuring derivation of the pedigree/folio tree for a land at a given time. A regional distributed land ledger representing the present regional ledger system and an island wide unified land ledger which addresses unequal regional land transaction density conditions across the island were proposed as solution models. The proposed models of the solution were implemented using Hyperledger Fabric vl.2. They were evaluated for performance on an AWS t2.large instance with 2 vCPUs, 8GiB memory, under different land transaction density conditions and node failure conditions. A community consisting of twenty-one peers belonging to nine organizations, was subject to evaluation. The island wide solution records higher throughput, lower latency and tolerance for fail-stop conditions than the regional distributed land ledger. Further, the island wide solution does not show a significant drop in throughput up to two crash failures out of seven Kafka brokers in production scale deployment.