Posts tagged #UTXO
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Bitcoin and quantum computing: counting for yourself with a node
The third piece of the «Bitcoin and quantum computing» family: not the numbers, but how to redo them. Every command needed to count for yourself, with your own node, how many coins already have their public key in view: the census of the UTXO set by lock type and by age, the pass that counts reuse, the outpoint index, the check of your own addresses without handing them to anyone. Three levels, from minutes to days, that can be left half done while still giving a verifiable result. Every step carries the real output of our own run at block 957,301 and the fingerprints anyone must land on by redoing it. Public code, MIT licence.
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Bitcoin's locks
Every coin on Bitcoin sits behind a lock: the scriptPubKey, the program that states under which conditions it can be spent. A reference piece on the lock types, from the first outputs of 2009 to Taproot and the quantum-resistant proposals: P2PK, P2PKH, bare multisig, P2SH, SegWit (P2WPKH and P2WSH), P2TR, each shown byte by byte on a real transaction verifiable with a node. What each type exposes of the public key, why a lock and an address are not the same thing, and how to read the language of scripts: pushes, ops and the stack.
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Bitcoin and quantum computing: the data (July 2026)
How much of all bitcoin already has its public key in view, since when, and at what pace it keeps exposing itself: 7.02 million BTC, about 35% of the circulating supply, of which 5.08 million exposed by address reuse and 1.93 million by construction (the original P2PK and Taproot). A census of the UTXO set at block 957,301, carried out with an ordinary node and reproducible down to the fingerprint, read table by table and figure by figure: concentration per lock, the curve by epoch of revelation, the pace of reuse year by year. This text is a deep dive off the path that starts from the post on the quantum computing threat: there the reasoning and the wider considerations, here the numbers and the method to check them with.