Enabling blockchain applications over named data networking

Blockchain can be used to ensure trust in a decentralized environment in which no trusted authority is available. Its original idea is to collect transactions in a block, and to chain the blocks together in such a way that attackers cannot forge the chain if the majority of the network is honest. Since its creation in 2008, blockchain technology has been used broadly in Internet to support decentralized payments, cloud computing, publishing, etc. This work focuses on public permissionless blockchain which neither guards against bad actors nor enforces access control. Named data networking (NDN) uses name-based routing and in-networking caching to support efficient content delivery, making it a promising future Internet architecture as well as a great network technology which can improve blockchain data delivery. Therefore, it is a very necessary task to enable deployment of blockchain applications over NDN. However, NDN is not immediately compatible with typical blockchain, since (permissionless) blockchain applications usually require broadcasting transactions and blocks in real time, which is not supported by the “pull” design of NDN. In this work, we propose BoNDN which enables blockchain applications over NDN. Unlike previous work, BoNDN follows the core design of NDN. We treat each type of blockchain data needed to be broadcast individually. Specifically, we rely on Interest broadcasting to support real-time broadcasting of blockchain transactions, which is small in size and can be brought by an Interest packet. In addition, we propose a subscription-push approach to support broadcasting of blockchain blocks, in which each miner performs subscription, and once a block is generated, the subscribed miner will receive the block

Enabling Resilient and Efficient Communication for the XRP Ledger and Interledger

The blockchain technology is relatively new and still evolving. Its development was fostered by an enthusiastic community of developers, which sometimes forgot about the lessons from the past related to security, resilience and efficiency of communication which can impact network scalability, service quality and even service availability. These challenges can be addressed at network level but also at operating system level. At network level, the protocols and the architecture used play a major role, and overlays have interesting advantages like custom protocols and the possibility of arbitrary deployments. This thesis shows how overlay networks can be designed and deployed to benefit the security and performance in communication for consensus-validation based blockchains and blockchain inter-operativity, taking as concrete cases the XRP ledger and respectively the Interledger protocol. XRP Ledger is a consensus-validation based blockchain focused on payments which currently uses a flooding mechanism for peer to peer communication, with a negative impact on scalability. One of the proposed overlays is based on Named Data Networking, an Internet architecture using for propagation the data name instead of data location. The second proposed overlay is based on Spines, a solution offering improved latency on lossy paths, intrusion tolerance and resilience to routing attacks. The system component was also interesting to study, and the contribution of this thesis centers around methodologies to evaluate the system performance of a node and increase the security from the system level. The value added by the presented work can be synthesized as follows: i) investigate and propose a Named Data Networking-based overlay solution to improve the efficiency of intra-blockchain communication at network level, taking as a working case the XRP Ledger; ii) investigate and propose an overlay solution based on Spines, which improves the security and resilience of inter-blockchain communication at network level, taking as a working case the Interledger protocol; iii) investigate and propose a host-level solution for non-intrusive instrumentation and monitoring which helps improve the performance and security of inter-blockchain communication at the system level of machines running Distributed Ledger infrastructure applications treated as black-boxes, with Interledger Connectors as a concrete case