Glassnode Co-Founder Counts 6.26 Million BTC With Exposed Public Keys

Some 6.26 million $BTC, or 31.2% of Bitcoin’s issued supply, sit behind public keys already visible onchain, according to an Oct. 8 update by Glassnode co-founder Rafael Schultze-Kraft.

The exposed balance has grown by 222,000 $BTC since Glassnode’s May report, while total supply increased by 64,000 $BTC, he said. The change reflects more existing coins entering the exposed category, not simply newly mined bitcoin.

The figures give a scale to the migration contemplated in Ethereum researcher Justin Drake’s “bunker mode” warning, which The Defiant previously covered. Drake urged preparations for hypothetical AI-assisted attacks on elliptic-curve cryptography. “At least that much would have to move” in a migration to addresses whose keys remain hidden behind a hash, Schultze-Kraft wrote.

Exposure is not evidence that Bitcoin’s cryptography has been broken. A visible public key supplies the starting point for a hypothetical attack that derives the corresponding private key; it does not itself give someone the ability to spend the coins.

Address Reuse Drives Most Exposure

Glassnode’s methodology counts exposure “at rest”: coins held in outputs whose public keys are already known, without waiting for the holder to spend them. It separates exposure caused by wallet practices from exposure built into an output’s design.

Schultze-Kraft’s breakdown attributes about 4.33 million $BTC to address reuse. Some output types initially hide public keys behind hashes, but spending reveals them. Any remaining or future balance tied to the same revealed key then loses that layer of protection.

Another roughly 1.94 million $BTC is exposed by output type, he said. Glassnode’s methodology includes early pay-to-public-key outputs, bare multisignature outputs and modern Taproot outputs in this category.

That distinction matters for anyone considering a move: a fresh Bitcoin address does not necessarily hide its public key. The Taproot specification explicitly includes the public key in the output. Taproot also uses Schnorr signatures rather than ECDSA, so the exposure tally is not an ECDSA-only count.

Drake’s warning remains a forecast, not a disclosed successful attack. Coinbase head of cryptography Yehuda Lindell challenged it, saying that, to his understanding, there was “no evidence whatsoever pointing to a break of decades old hardness assumptions like elliptic curve cryptography.”

Nor does keeping a key hidden at rest make coins immune to every future attack. Glassnode distinguishes that protection from the period when a spend reveals the key. Drake himself urged holders not to rush, warning that “a rushed migration would do more harm than good.”