Glassnode: 4.12M BTC at Quantum Risk From Key Mismanagement — Double the Legacy Script Exposure

New Glassnode data reveals that 4.12 million BTC is operationally exposed to quantum risk through behavioral factors — address reuse, partial spending, and poor custody practices — more than double the 1.92 million BTC exposed by Bitcoin's older script architecture. Combined, the two categories put 30.2% of all issued Bitcoin within theoretical quantum reach.

The firm draws a sharp line between structural and operational exposure. Structural risk covers outputs where the public key appears on-chain by design: P2PK outputs from Bitcoin's earliest blocks, bare multisig, and Pay-to-Taproot (P2TR) scripts. Operational risk is different — P2PKH and P2WPKH addresses hide public keys behind hash functions that are considered quantum-resistant, but that protection evaporates the moment a holder spends from the address. Broadcasting a spend transaction permanently publishes the public key…