Bitcoin SPV Feasibility

Bitcoin SPV Feasibility in Zenon

Technical Notes on Cryptographic Possibility

Summary

This document outlines the cryptographic primitives necessary for verifying Bitcoin transaction inclusion (SPV) within Zenon’s ledger model. The goal is to establish whether such verification is mathematically possible given Zenon’s architecture, not whether it is currently implemented.

What SPV Verifies

SPV (Simplified Payment Verification) proves that a Bitcoin transaction was included in a valid Bitcoin block with sufficient proof-of-work. It does NOT require downloading or verifying the full Bitcoin blockchain.

SPV provides:

• Proof that a transaction was included in a Bitcoin block
• Verification that the block has valid proof-of-work
• Confirmation depth (how many blocks built on top)

SPV does NOT provide:

• Validation of Bitcoin script execution
• UTXO set verification
• Full Bitcoin consensus participation

Required Cryptographic Operations

1. SHA-256 Double Hash

Bitcoin headers use SHA256(SHA256(header)) for proof-of-work. This is a standard hash operation available in any cryptographic library.

block_hash = SHA256(SHA256(80_byte_header))

2. Target Comparison

A Bitcoin block is valid if its hash (interpreted as a number) is below the difficulty target:

block_hash <= target_from_bits

This is a simple integer comparison after decoding the “bits” field.

3. Merkle Proof Verification

Given a transaction hash and a Merkle branch, reconstruct the Merkle root and compare:

computed_root = MerkleReconstruct(tx_hash, branch)
valid = (computed_root == header.merkle_root)

Each step is two SHA256 hashes. A typical branch has 10-14 levels.

Feasibility in Zenon

Account-Chain Context

Zenon’s account-chain model allows individual accounts to perform local verification without affecting global consensus. An account could:

1. Receive a Bitcoin SPV proof as transaction data
2. Perform local verification (hash operations, comparisons)
3. Update local state based on verification result
4. Have this state checkpointed by Momentum

Computational Requirements

This is computationally trivial on any modern processor.

Data Requirements

This is small enough to include in a standard transaction.

What Would Be Needed

For Zenon to verify Bitcoin SPV proofs, it would need:

1. SHA256 primitive: Standard cryptographic function
2. Header parsing: Decode 80-byte Bitcoin headers
3. Target decoding: Convert “bits” field to difficulty target
4. Merkle verification: Reconstruct root from branch

All of these are standard operations with no novel cryptography required.

Open Questions

This document establishes cryptographic feasibility. Implementation would require additional work on:

• How accounts obtain Bitcoin headers (data availability)
• How to prevent eclipse attacks (multiple sources)
• Economic incentives for header providers
• Integration with existing Zenon transaction model

These are engineering questions, not cryptographic barriers.

Conclusion

Bitcoin SPV verification is cryptographically possible within Zenon. The required operations (SHA256, integer comparison, Merkle proofs) are standard primitives with no special hardware or novel cryptographic assumptions needed.

The question is not “can Zenon verify Bitcoin proofs?” (yes, trivially), but “should Zenon implement this, and how?”

Status: Feasibility confirmed Requires: Standard cryptographic primitives only Blockers: None (cryptographic)