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SeT: SeT: Secure Service Technology Secure Service Technology

for Dependable e-Business/Government Applicationsfor Dependable e-Business/Government Applications

Jie Xu, Keith Bennett and Malcolm Munro

The SeTech Centre

Department of Computer Science

University of Durham

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The SeTech Centre at DurhamThe SeTech Centre at DurhamFunding Sources: EPSRC/DTI, NEeS CentreIndustrial Partners (Sun, Sharp, Sparkle etc)

Technical Board:Jie Xu (Distributed Systems & Dependability)Keith Bennett (Service-Based Architecture)Malcolm Munro & Nick Holliman (Visualisation)

Research Staff:6 Academic Staff Members + 12 Research Staff Members

Hardware Testbed:A Sun 32 CPU UltraGrid computer connected to a network of Sun servers and workstations with an upgraded Gigabit link between Durham and Newcastle

Close Collaborations: The Pennine Group, EU and USA univ. & insti.

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The SeTech Centre BuildingThe SeTech Centre Building

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Problems and ChallengesProblems and Challenges

The Problem

- Coordinated resource sharing & problem solving in large- scale, dynamic, multi-institutional virtual organisations

Major Technical Obstacles

- Inflexible, protocol-specific architectures & approaches- Difficulty in structuring and writing such large-scale programs- Security risks and malicious attacks- Many risks and problems rooted in software

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ee-Demand:-Demand: A Software-BasedA Software-Based SolutionSolution

The Demand-Led Service-Based Architecture - New service-based model for organising flexible e-business/ government applications - An instance of the architecture to be implementedGeneric Services, e.g. our unique SIR technique - Support for secure and attack-tolerant information sharing - 3D visualisation service for program/information comprehension

Fault-Injection-Based System Evaluation - The FITMVS tool, supported by clusters of workstations - Evaluation with respect to faults/attacks/performance

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Architectural EvolutionArchitectural Evolution

Applications

Transport

Internet

Link

Internet Architecture

Resources

Connectivity

Resource Management

Coordination ofMultiple Resources

Applications

Protocol-Based Architecture

e-Actions

Service-Based Architecture

ISPs, CSPs, SPs

Information, NegotiationSettlement, After-Services

Generic Services:Security, FTVisualisation

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Service-Based Architectural ModelService-Based Architectural Model

Contractor/assemblyservice provider

Contractor/assemblyservice provider

Catalogue/ontologyprovider

Catalogue/ontologyprovider

Serviceconsumer

Service/solutionprovider

Demand

Provision

Ultra-Late Binding

Finding

Publishing

e-Action service

Attack-tolerance service

Auto-3D service

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The Attack-Tolerant PIR SchemeThe Attack-Tolerant PIR Scheme Private Information Retrieval (PIR) - Normal query to a (remote) database: give me the record x - PIR query: compute functions F1, F2, …, Fk for me over x, y, z, ...

(reconstruct x locally based on the results of F1, F2, …, Fk) Attack/Failure Models of Remote DB Servers - Honest-but-Curious (HbC): query with K functions (computing tasks) - HbC & loss of results: query with K + L functions - Malicious hosts (may change the results deliberately): 2 different queries (i.e. 2K functions for detection) or (f + 2) queries for tolerating f attacks/failures

New Approach: a query with K signed functions (detection) for tolerating f attacks/failures

Application Domains: critical information services, healthcare etc.

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The System Architecture The System Architecture

A11 A12 A1m

A21 A22 A2m

An1 An2 Anm

request manager

mobile code dispatcher

request

A1A2

An

(local host)user application

A1, A2 … An

result manager

mobile code collector

result

A1, A2 … An

Internet

host 1 host 2 host m

(pieces of code)

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An Implementation for Real DBsAn Implementation for Real DBs (Mobile Code Enabled) Network Environment

IncomingDaemon

IncomingDaemon

Arrival

OutgoingDaemon

OutgoingDaemon

Dispatching

RequestProcess

RequestProcess

RemoteServices(e.g. databases)

IncomingDaemon

IncomingDaemon

Arrival

OutgoingDaemon

OutgoingDaemon

Dispatching

RequestProcess

RequestProcess

RemoteServices(e.g. databases)

IncomingDaemon

IncomingDaemon

Arrival

OutgoingDaemon

OutgoingDaemon

Dispatching

RequestProcess

RequestProcess

RemoteServices(e.g. databases)

H1 H2Hm

SeCode ServicesSeCode Services

User ApplicationUser Application

REQUEST RESULT

Local Host

pieces of code pieces of code

Private Information Retrieval Computation over Finite Field

0

20000

40000

60000

80000

100000

120000

140000

160000

1 2 3 4 5 6 7 8 9 10 11 12 13 14

Length of quries

Pro

ces

sin

g t

ime

(m

s)

s

k

n

primeS

F0

Time

Length of Queries vs.Execution Time