Audience member cites a lawyer arguing encrypt-and-lose-key is insufficient because future quantum computers may decrypt archived data. Davydov agrees but notes quantum computers will create many other problems too. A follow-up comment from the audience describes a Polish banking production practice borrowed from blockchain: store payloads separately from the event log, keep only fingerprints inside events to prove immutability, and delete the payload when requested — if an event later refers to a deleted payload, return 'sorry, deleted'.