A recovery phrase locked in a physical drawer offers no protection against that, as the attacker would be working from information already sitting on the blockchain.
Some later payment formats hide the public key behind a hash, a digital fingerprint, until the owner spends. An attacker targeting a previously hidden key would have to wait for that exposure and might need to recover the secret quickly enough to interfere with the payment.
That is also why lost coins present a difficult problem. Bitcoin can introduce stronger spending protections, but someone still needs the existing keys to move old holdings into them. If those keys are lost, the owner cannot make the move. The exposed public key remains available to a future attacker.
Some of bitcoin’s oldest holdings have had their public keys exposed since they were mined.
Old coins have also been moving as the quantum debate grows louder. On Oct. 7, 100.02 $BTC untouched since July 2010 moved after more than 16 years, carrying a value of about $8.5 million. In August, six wallets inactive since 2011–2014 moved another 553.59 $BTC, worth roughly $40 million at the time.
Those transfers do not singularly establish that holders are responding to quantum fears, as moving coins can even mean changing wallets, reorganizing holdings or preparing to sell.
