Bitcoin BSV mainnet · checked in this tab
Don't trust BSVKey. Check it.
Every product we ship leaves proof on chain. This page downloads the raw transactions and block headers, then redoes the math itself: hashes, Merkle paths, proof of work. Our servers are not involved, so if we lied, this page would say so.
0of 12 verified
- Blocks mined on top
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- Hashes to rewrite the oldest
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- Chain tip
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- Status
- Starting
The wall
Each card is one transaction and the claim we make about it. Five checks must pass. Press Tamper on any card to flip one byte and watch the checks catch it.
Check any transaction
Paste a Bitcoin BSV mainnet txid. Same checks, same code, no claim attached, so you see exactly what the chain holds.
How it works
- Bytes to txid. The raw transaction is double SHA-256 hashed here. If one byte were changed, the id would not match.
- Merkle path. The txid is folded up the block's Merkle branch, hash by hash, until it reaches a root.
- Block header. The 80-byte header is rebuilt and hashed. Its Merkle root must equal the one we just computed.
- Proof of work. The header hash must sit below its own difficulty target, and that difficulty must be above 10^9, far beyond what a forger could produce cheaply.
- The claim. The data inside the transaction is decoded and compared with what we publish: the exact root, record or payment.
What you still trust
The raw bytes come from WhatsOnChain's public API, but nothing it sends is believed: a wrong byte fails a check. The one thing taken on its word is chain height, used for the "blocks mined on top" count. To remove even that, compare the block heights against any Bitcoin BSV node you run.
Each card can download its evidence as JSON. node verify.mjs evidence.json runs the same checks offline.