泛用於結構化同儕網路之匿名傳遞架構

An Anonymous Universal Relay Architecture over Structured Peer-to-peer Networks

李俊頡(Jiunn-Jye Lee)

指導教授 ： 雷欽隆

國立臺灣大學/電機資訊學院/電機工程學研究所/博士(2012年)

https://doi.org/10.6342/NTU.2012.02776

摘要

本論文提出兩種可建構於現今已發表眾多結構化同儕網路之訊息傳遞架構，第一種架構提供同儕網路上使用者資訊傳遞之匿名安全性。此架構為與Crowds相似，其特點在於能以不變更所植基之結構化同儕網路的前提下給與使用者多種匿名安全等級之資訊傳遞。透過同儕網路內部建立之轉送路徑，資料發布者即能在不洩漏己方來源的狀況下取得內部同儕服務與外部網際網路服務。此外，針對區域網路分析類型之攻擊者，本架構亦提供名為「偽造路徑銜接」的方式予以抵擋。資料轉送路徑建立的部份亦提供兩種不同的路由模式，讓使用者能依據所需之匿名安全等級加以選擇。本架構之效能與匿名安全性亦於分析與模擬結果證實優異於其他以發表之匿名系統。
一般而言，同儕網路的成員隨時可能進入或離開系統。但在結構化同儕網路中，頻繁進出卻會造成龐大的維護成本。本論文所提出第二種名為「植基於區段分割之自適性路由模型」的架構，即為針對此問題之改善方案。此架構藉由動態切割鍵值空間的方式將同儕網路分為許多區段，每個區段有一個超級節點扮演轉送代理伺服器，負責轉發同區段節點往來請求與回覆訊息。一旦區段內同儕節點的數量超過預設的上限值，此區段即自動分割成為兩個新的區段。如此一來，超級節點的流量與運算負載即能保持在可承受的範圍內。為了便於闡釋本架構，我們採用Chord做為底層的結構並以此組合進行一系列的模擬分析。模擬與分析的結果均顯示本架構能有效減低同儕網路節點進出的通訊傳輸成本，並縮短同儕網路內訊息傳遞的路徑長度。

關鍵字

匿名性 ； 結構化同儕網路 ； 匿名網路 ； 分區切割 ； 雙層路由 ； 網路安全

並列摘要

In this dissertation, two architectures built on-top-of existing structured peer-to-peer networks are proposed. The first is a Crowds-like architecture proposed to provide different levels of sender anonymity. The goal of sender anonymity is achieved by constructing relay paths that hide the sender from others. Users are able to anonymously request both internal peer-to-peer services and external Internet ones via a relay path. The proposed architecture can be integrated into a structured peer-topeer network without penalty, that is, the anonymous path is constructed without modifications to the underlying peer-to-peer networks. Moreover, an enhanced feature called dummy path composition is provided to resist local traffic analysis attack, and there are also two kinds of routing methods with different degree of anonymity to fulfill user requirements. Through analysis and simulations, we show that our system outperforms existing systems on both performance and anonymity.
It is common that members of a peer-to-peer network join and leave the system at any time. But in a structured peer-to-peer network, frequent joining and leaving may cause huge maintenance overhead. To deal with this churn problem,
we also proposed a two-tier architecture called adaptive sector-based routing model (ASBRM). In ASBRM the key space is divided into several sectors and each one has a super peer who plays the role of the relay proxy of the sector. When the number of peer members in a sector exceeds a predefined threshold, it will split into two sectors so that the traffic and computational overhead of the super peer can be kept within an acceptable range. For the convenience of explanation, we combine ASBRM with Chord and perform a series of simulations. Both analysis and simulation results show that ASBRM achieves lower communication cost of members’joining and leaving while at the same time the message routing path length is also
shortened.

並列關鍵字

Anonymity ； structured peer-to-peer network ； anonymous network ； sector-based ； two-tier routing ； network security

參考文獻

[2] Jiunn-Jye Lee, Li-Yuan Lee, and Chin-Laung Lei. An anonymous universal relay architecture over structured peer-to-peer networks. International Journal of Innovative Computing, Information and Control (IJICIC). Accepted at

August, 2012.

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