Securing the Web of Things

Transcription

1 Securing the Web of Things A COMPOSE Perspective Daniel Schreckling University of Passau 1 st W3C WoT IG F2F Open Day April 20, 2015

2 High- Level COMPOSE Architecture 2

3 Main Design Decision The situation Changing use and types of principals and data Unpredictable interactions & information flows Security is application dependent: Applications require specific security mechanisms at specific locations Inflexible, resource- centric security frameworks COMPOSE approach Shrink security perimeter to the granularity of data Build flexible, data- centric but scalable security framework 3

4 Identity Management Attribute- based Entities associated with set of attributes Attributes Describe properties Fixed or user- defined but approved Defined decentralized Lightweight Partial replication of OAuth (access tokens) Use of API tokens for highly frequent interactions Flat entity hierarchies 4

5 Security Meta Data for Virtual Things Weather Security Association Policies Reputation 5

6 Data and s Weather Weather forecast Flow Policies Security State Provenance Security Association Policies Reputation Contracts 6

7 Flow Policies for Data Tagged to data (JSON document) Defined over actors and their attributes Flow- to- rule A Lock 1 (a 1, a 2,, a q ), Lock 2 (b 1, b 2,, b r ), Lock i (z 1, z 2,, z t )! Flow- from- rule A! Lock 1 (a 1, a 2,, a q ), Lock 2 (b 1, b 2,, b r ), Lock i (z 1, z 2,, z t ) Set of rules U! form owner(u), policies validated, atwork(u), authenticated(u) Data Item 20 April

8 Data- Centric Entity Policies Flow-Control: S! actsonbehalf(s, U) in 1 in 2 Device/ S out 1 Access Control: U! authenticated(u), minbalance(u, 1.5 Cent) S! mintrustlevel(s, 5) Flow-Control: owned(s, U)! S 20 April 2015 COMPOSE Consortium 8

9 Contracts Promises towards the platform Automatically generated Over- approximated service behaviour Flow description: length(in2)<=8!out 1 Pre- Condition: Encrypted in 1 in 2 delete Resource X Developer Contracts are user- defined refinements Impact Performance Trust in Developers out 1 Effect: Resource Z Encrypted( /etc/* ) hasname( /etc/passwd ) 9

10 User Deployed s/applications Weather Weather forecast Location Places to meet your friends 10

11 User Deployed s Weather Weather forecast Fun things to do Location Places to meet your friends 11

12 Security Conflicts Weather Weather forecast Fun things to do Location Places to meet your friends Framework detects flows with conflicting constraints Resolution using user, instrumentation and/or dynamic monitors 12

13 Dynamic Flow Control Weather Weather forecast JSFlow* Fun things to do Location JSFlow* JSFlow* Places to meet your friends 13

14 Static Flow Control Node/ Analysis (enhanced TAJS, Klee) Contracts Instrumentation (Dynamic Enforcement, Provenance, Reputation) Composition Analysis Composition Reconfiguration glue.things Composition creation Policy Settings User Feedback Flow Policies Composition Recommendation 14

15 Hybrid Flow Control Weather Weather forecast JSFlow* Fun things to do Location JSFlow* JSFlow* Places to meet your friends 15

16 Hybrid Flow Control Weather Weather forecast Fun things to do Location Places to meet your friends Reputation April 20, 2015 Declassifier Provenance COMPOSE Consortium 16

17 Hybrid Flow Control Weather Weather forecast Fun things to do Location Places to meet your friends Declassifier Reputation Provenance 17

18 Limitations Security of physical devices Authentication Tamper- proof Interface/Firmware security Data confidentiality & integrity Effective Perimeter remains at cloud level Privacy vs. Security Use of existing technologies Analysis tools and instrumentation Low language coverage Efficiency vs. false positive rates 18

19 Conclusions The COMPOSE way of WoT Introduces required control for the open IoT Shows that flow control frameworks appear to be a perfect match Creates new dimensions for policy enforcement BUT Induces storage and processing overhead Dynamic security enforcement architectures Does the WoT want to face this fine granularity? 20 April 2015 COMPOSE Consortium 19