Table 6: Comparison of approaches.

Security adaptation approach(1) An architectural approach for self-managing security services(2) A software framework for autonomic security in pervasive environments(3) Context sensitive adaptive authentication(4) Adaptive messaging middleware(5) Adaptive security architecture based on EC-MQV algorithm in personal networks

Adaptation viewpoint
Object to adaptGeneric approachGeneric approachAuthentication mechanismGeneric approachKey agreement algorithm
Adaptation timingRuntime, reactive, and proactiveRuntime and reactiveRuntime and reactiveRuntime, reactive, and proactiveStart-up
Monitor and analysesMonitoring and analysing composed inside the Context subsystem by means of dedicated services for trust level, threat level, availability, memory usage, and bandwidth usage. The internal design of services is not described.Monitors: beforehand defined security events.
Analyses: decides to reconfigure based on monitored events. How a decision is made is not described.
Monitors: location of user’s devices and timestamps.
Analyses: ULPC partially analyses monitoring results by means of the developed fusion algorithms. The application has to conclude the current authentication level.
Monitoring: security measuring is the most emphasised form of monitoring.
Analyses: the separated component composes the monitoring results to the higher level. The internal design of this component is not described.
Monitors location and device capabilities.
Analyses: beforehand analysed.
Planning and executionPlanning: static planning by the means of ECSA policies.
Execution: ECSA Policy manager enforces beforehand defined actions.
Planning: in high level
Execution: —
Planning: —
Execution: —
Planning and execution are composed into the one phase called Adapt. However, the content of this phase is not described.Planning: static planning, that is, beforehand defined actions for different locations.
Execution: beginning of each communication session.
KnowledgeInside the monitoring services and ECSA policies. Profile database (content is not described)Adaptive database (content is not described)
Self-propertiesSelf-configuration, optimization, and protection.
Context-awareness
Self-configuration, optimization, and protection.
Context-awareness
Self-configuration.
Context-awareness
Self-configuration, optimization, protection, and healing.Context-awareness

Security viewpoint
MechanismsGeneric approachGeneric approachAuthentication mechanismGeneric approachKey agreement algorithm
AttributesGeneric approachGeneric approachAuthenticationGeneric approachConfidentiality and integrity
Protected assetGeneric approachGeneric approachUser’s identityGeneric approachData in communication channel
ThreatsGeneric approachGeneric approachIdentity theftGeneric approachThreats for the communication confidentiality and integrity.

Lifecycle viewpoint
ArchitectureStructure is described. Middleware under the application layer contains elements for adaptation.
Behaviour is not described.
Structure and behaviour of the approach are described. Separated components for monitoring, analysing, and responding.Structure and behaviour of the approach are described.
Separated components for monitoring and analysing.
Structure is described. The ASM component performs all adaptation tasks. The component contains monitor, analyse, and adaptation parts.
Behaviour is not described.
Structure is described. Layer between application and security protocol.
ExtensibilityCompletelyCompletelyNoPartiallyPartially
FlexibilityEasyEasyHardModerateEasy
ReusabilityIt is possible to reuse the whole approach or individual components.It is possible to reuse the whole approach or individual components.It is possible to reuse the whole approach. Individual components can be also reused, but the functionality is strongly related to this approach.Reusing the whole adaptation approach requires that the GEMOM middleware is utilised as a whole, which causes additional work. Reusing individual monitoring (measuring) parts will be easy.CaSM component can be reused. It is notable that the component is intended for the start-up phase adaptations.
MaturityValidation No
Guidelines No
Community No
Validation No
Guidelines No
Community No
Validation Yes
Guidelines partially Yesa  
Community No
Validation Yes
Guidelines No
Community No
Validation No
Guidelines No
Community No

aSeparated guidelines are not available. However, the existing papers describe the monitored attributes and the fusion algorithm in detail, and thus these can be implemented by means of this input.