1.7 KiB
1.7 KiB
Trust Decay / Freshness F(e) with Configurable Tau Values
Module
VexLens
Status
IMPLEMENTED
Description
Freshness decay with configurable tau values per source class, implementing the F(e) = exp(-delta_days/tau) formula described in the advisory.
Implementation Details
- Trust decay service:
src/VexLens/StellaOps.VexLens/Trust/SourceTrust/TrustDecayService.cs,ITrustDecayService.cs-- manages trust decay calculations - Decay calculator:
src/VexLens/StellaOps.VexLens/Trust/SourceTrust/TrustDecayCalculator.cs-- implements F(e) = exp(-delta_days/tau) formula with configurable tau per source class - Trust weight engine:
src/VexLens/StellaOps.VexLens/Trust/TrustWeightEngine.cs,ITrustWeightEngine.cs-- integrates decay into trust weight computation - Core trust engine:
src/VexLens/StellaOps.VexLens/StellaOps.VexLens.Core/Trust/TrustWeightEngine.cs,ITrustWeightEngine.cs - VEX source trust score:
src/VexLens/StellaOps.VexLens/Trust/SourceTrust/VexSourceTrustScore.cs-- trust score model including freshness component - Trust score cache:
src/VexLens/StellaOps.VexLens/Trust/SourceTrust/InMemorySourceTrustScoreCache.cs-- caches computed trust scores - Options:
src/VexLens/StellaOps.VexLens/Options/VexLensOptions.cs-- configurable tau values per source class - Source: Feature matrix scan
E2E Test Plan
- Verify F(e) = exp(-delta_days/tau) produces correct decay for different delta values
- Test configurable tau per source class (vendor vs. community vs. unknown)
- Verify decay correctly reduces trust score for stale VEX statements
- Test fresh VEX statements maintain full trust weight
- Verify trust score cache invalidation on new statements