| name | gossip-cache-invariance |
| description | L1 trigger - audits message and seen caches for write-after-validate ordering, eviction safety, and duplicate handling. |
Injectable Skill: Gossip Cache Invariance
L1 trigger: P2P flag AND (seen_cache, message_cache, tx_cache, gossipsub, pubsub, dedup, seen_chunks detected)
Inject Into: depth-network-surface, depth-consensus-invariant
Language: Go and Rust
Finding prefix: [GCI-N]
1. Write-After-Validate
For each attacker-controlled cache key, prove the ordering between cache write
and integrity/authenticity validation. Cache insertion before validation is a
poisoning primitive.
Tag: [GOSSIP-CACHE:ORDER]
2. Duplicate Handling
Check whether duplicate suppression is keyed on canonical content, the right
topic/partition, and enough sender identity. Look for cases where legitimate
messages are suppressed or malicious messages can be replayed after eviction.
Tag: [GOSSIP-CACHE:DUPLICATES]
3. Eviction Invariants
Under burst traffic or memory pressure:
- what gets evicted first?
- can attacker traffic evict honest messages before processing?
- can eviction reopen a previously rejected malicious message?
Tag: [GOSSIP-CACHE:EVICTION]
4. Cache Key Soundness
Verify the key includes the right tuple of topic / partition / chain / message
identity. Flag collisions where distinct messages alias to the same cache key.
