Universitatea Politehnica Bucureşti - Facultatea de Automatică şi Calculatoare

TOWARDS A SECURE DATA SHARING PEER-TO-PEER NETWORK BASED ON

GEOMETRIC AND SEMANTIC DISTANCES

Authors: Ana-Delia Sâmbotin, Mugurel Ionut Andreica

E-mail: delia.sambotin@gmail.com, mugurel.andreica@cs.pub.ro

21.04.23 1

Universitatea Politehnica Bucureşti - Facultatea de Automatică şi Calculatoare

Outline

• Introduction

• Goals

• Design

• Architecture

• Experimental Evaluation

• Conclusion

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Universitatea Politehnica Bucureşti - Facultatea de Automatică şi Calculatoare

Introduction

• P2P overlay topology in which nodes communicate one-to-one with their neighbors

• Resource (file) sharing

• Find a given resource (file)

• Find similar resources (files) to a given resource (file)

• Transfer a given resource (file) (hop-by-hop in the P2P topology)

• Security

– Data transfer encryption

– Anonymization

– Avoid traffic analysis

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Universitatea Politehnica Bucureşti - Facultatea de Automatică şi Calculatoare

Goals

• Similarity search based on implicit user attributes (i.e. extracted automatically, not explicitly expressed by the users)

• Better chances of finding a given resource (similar resources) quickly when using bounded flooding for search)

• Good data transfer performance (e.g. data transfer speed)

• Security and privacy (encryption, anonymization, etc.)

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Universitatea Politehnica Bucureşti - Facultatea de Automatică şi Calculatoare

Design

• Each peer computes a set of coordinates in a D-dimensional space, based on:

– Network round-trip time (RTT)

– Semantic distance (i.e. similarity of resources to other peers)

• In a distributed manner, each peer will select as neighbors in the topology other peers with small distances to it (based on the distance in the geometric space)

– Network RTT => good data transfer performance in hop-by-hop data transfers

– Semnatic closeness => good chance of finding a given resource (file) or similar resources (files) nearby (among its neighbors or at most a given distance R away from it)

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Universitatea Politehnica Bucureşti - Facultatea de Automatică şi Calculatoare

Architecture

• Main modules related to:

– Network communication (low-level)

– P2P topology construction and maintenance

– Data transfer

– Resource (file) search

– Security

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Universitatea Politehnica Bucureşti - Facultatea de Automatică şi Calculatoare

Architecture

• Two main roles: Bootstrap node and normal node

• The nodes will first contact the bootstrap nodes in order to find a set of nodes already in the system; afterwards, they organize themselves

• Different types of strategies for constructing the P2P overlay

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Universitatea Politehnica Bucureşti - Facultatea de Automatică şi Calculatoare

Strategies for the P2P overlay

• A network of “supernodes”, that “hide” a group of peers

• A “supernode” can be considered to be a “proxy” node

• Geometric coordinates computed based on network abd semantic distances between a peer and a subset of other peers

• (Resource or Similarity) Search strategy – bounded (distance) flooding

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Universitatea Politehnica Bucureşti - Facultatea de Automatică şi Calculatoare

Architecture - formulas

• Network distance metric

• Semantic distance (based on the common resources)

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Universitatea Politehnica Bucureşti - Facultatea de Automatică şi Calculatoare

Security Module

• Anonymization: using mediators

• Avoiding traffic analysis

– Dummy search terms in a search query

– Dummy search queries

• Encryption of data transfers using public/private keys

Universitatea Politehnica Bucureşti - Facultatea de Automatică şi Calculatoare

Evaluation – Distance metrics

• Evaluation (through simulation) of

peer distribution in 2D when: (c)

– Using only the network distance (a)

– Using only the semantic distance (b)

– Using a combination of both metrics (c)

(a) (b)

Universitatea Politehnica Bucureşti - Facultatea de Automatică şi Calculatoare

Evaluation – Using Mediators

• Duration of a search query:

– Secure (encrypted messages) with mediator

– Secure (encrypted messages) without mediator

– Unsecure (without mediator)

• Encryption slows things down (up to 30%-35%)

• Using a mediator does not have a meaningful negative impact on performance

Universitatea Politehnica Bucureşti - Facultatea de Automatică şi Calculatoare

Conclusions

• Proposed a P2P-based data sharing system with:

– Enhanced security attributes (anonymization and encryption)

– A combination of network distance (RTT) and semantic distance for building the overlay

• Experimental results are promising

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Universitatea Politehnica Bucureşti - Facultatea de Automatică şi Calculatoare

The end

• Thank you!

• Questions?

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