栗原 淳

Beyond 5G での活用も考慮したモバイルネットワークのユースケースの一つとして，低消費電力かつ計算能力の低い IoT 端末を多数接続する Massive IoT 環境が挙げられる．本環境下で効率的にネットワーク資源を利用するためには，多数の IoT 端末からアップロードされるデータの圧縮・通信量の削減が必要である．本検討では，Multi-access Edge Computing (MEC) 環境を想定し，エッジノードを用いた Massive IoT 環境におけるデータ圧縮について検討する．特に，近年注目が集まりつつある，軽量かつ IoT センシングデータ等を効率的に圧縮できる，重複削除によるストリームデータ圧縮手法 “Generalized Deduplication (GD)” の適用を考慮する．基本的な GD のアルゴリズムは，1 対 1 でのストリーム送受信を前提としている．そのため本報告では，その手法を拡張して，1 対多（エッジノード対 IoT 端末）の MEC 環境に適した，効率的なアルゴリズムを提案する．具体的には，1 対多環境における GD 活用での辞書構築に関する検討と，その効率についての基礎的な評価について報告する． One of the use cases of mobile networks that can be considered for use in Beyond 5G is a massive IoT environment where many IoT terminals with low power consumption and computing power are connected. In order to efficiently use network resources in this environment, it is necessary to compress and reduce the amount of data uploaded by a large number of IoT terminals. In this study, we consider data compression in a Massive IoT environment using edge nodes, assuming a Multi-access Edge Computing (MEC) environment. In particular, we consider the application of "Generalized De-duplication (GD)", a stream data compression method based on duplicate deletion, which has been attracting attention in recent years for its lightweight and efficient compression of IoT sensing data and other data. The basic GD algorithm assumes one-to-one stream transmission and reception. In this report, we propose an extension of the GD algorithm that is suitable for one-to-multi (edge node and IoT terminals) MEC environments and has more efficient performance. Specifically, we examine dictionary construction for GD utilization in a one-to-multi environment and report a basic evaluation of the efficiency of the proposed algorithm.

The traditional Domain Name System (DNS) lacks fundamental features of security and privacy in its design. As concerns of privacy increased on the Internet, security and privacy enhancements of DNS have been actively investigated and deployed. Specially for user's privacy in DNS queries, several relay-based anonymization schemes have been recently introduced, however, they are vulnerable to the collusion of a relay with a full-service resolver, i.e., identities of users cannot be hidden to the resolver. This paper introduces a new concept of a multiple-relay-based DNS for user anonymity in DNS queries, called the mutualized oblivious DNS ($\mu$ODNS), by extending the concept of existing relay-based schemes. The $\mu$ODNS introduces a small and reasonable assumption that each user has at least one trusted/dedicated relay in a network and mutually shares the dedicated one with others. The user just sets the dedicated one as his next-hop, first relay, conveying his queries to the resolver, and randomly chooses its $0$ or more subsequent relays shared by other entities. Under this small assumption, the user's identity is concealed to a target resolver in the $\mu$ODNS even if a certain (unknown) subset of relays collude with the resolver. That is, in $\mu$ODNS, users can preserve their privacy and anonymity just by paying a small cost of sharing its resource. Moreover, we present a PoC implementation of $\mu$ODNS that is publicly available on the Internet. We also show that by measurement of round-trip-time for queries, and our PoC implementation of $\mu$ODNS achieves the performance comparable to existing relay-based schemes.