eth: implemented peer consensus based witness verification

[pratikspatil024]

Description

Implemented peer consensus based witness verification

1. Warning Threshold System
   • Triggers verification when a peer reports # pages > allowed (calculated dynamically)
   • Peers under threshold are assumed honest
2. Peer Consensus Verification
   • Query 2 random peers for verification
   • Use collective peer knowledge to detect malicious behaviour
3. Peer Management
   • Drop peers immediately
   • Cache verification results to avoid redundant checks

CheckWitnessPageCount() - Entry point for verification
verifyWitnessPageCount() - Core consensus logic
RequestWitnessesWithVerification() - Verification-enabled witness requests
getAllPeers() - Random peer selection support

//configs
const (
    witnessPageWarningThreshold = 10               // Trigger verification threshold
    witnessVerificationPeers    = 2                // Number of peers to query
    witnessVerificationTimeout  = 5 * time.Second  // Query timeout
    witnessVerificationCacheTTL = 10 * time.Minute // Cache duration
)

Verification Flow:

1. Node A requests witness 0xABC... from Peer B.
2. Downloads Page 0, learns there are 50 total pages.
3. Locks TotalPages = 50.
4. Calculates threshold → ceil(45MB / 15MB) = 3 pages.
5. Since 50 > 3, pauses to verify.
6. Downloads Pages 1, 2, and 3 (up to threshold).Bandwidth used so far: 48MB.
7. Cache check → MISS.
8. Selects two random peers → Peer C and Peer D.
9. Requests metadata (WIT2) from both peers.
10. Both report: TotalPages = 50, Size = 800MB, Block = 12345.
11. Bandwidth for metadata: 180 bytes.
12. Calculates consensus → majority agrees on 50 pages.
13. Peer B deemed honest.
14. Caches result {0xABC...: 50 pages, TTL = 10 min}.
15. Resumes download from Peer B (Pages 4–49).
16. Validates each page (total count, page index, limits).
17. Completes full download (50 pages = 800MB).
18. Reconstructs witness and imports it.

Changes

• [ ] Bugfix (non-breaking change that solves an issue)
• [ ] Hotfix (change that solves an urgent issue, and requires immediate attention)
• [ ] New feature (non-breaking change that adds functionality)
• [ ] Breaking change (change that is not backwards-compatible and/or changes current functionality)
• [ ] Changes only for a subset of nodes

Breaking changes

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Nodes audience

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Checklist

• [ ] I have added at least 2 reviewer or the whole pos-v1 team
• [ ] I have added sufficient documentation in code
• [ ] I will be resolving comments - if any - by pushing each fix in a separate commit and linking the commit hash in the comment reply
• [ ] Created a task in Jira and informed the team for implementation in Erigon client (if applicable)
• [ ] Includes RPC methods changes, and the Notion documentation has been updated

Cross repository changes

• [ ] This PR requires changes to heimdall
  • In case link the PR here:
• [ ] This PR requires changes to matic-cli
  • In case link the PR here:

Testing

• [ ] I have added unit tests
• [ ] I have added tests to CI
• [ ] I have tested this code manually on local environment
• [ ] I have tested this code manually on remote devnet using express-cli
• [ ] I have tested this code manually on amoy
• [ ] I have created new e2e tests into express-cli

Manual tests

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Additional comments

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