nostr:npub10ndka8lfpun2fxrxzfj39fnzmtn83rwut6yn84kw4z2f3amgtlrsc3vwd2 With the old EBS system, every radio station got a list of daily authenticator words in a sealed envelope once a month. You weren't supposed to open it unless an alert came in, since the authenticators were the same for everyone (since the alerts were broadcast). They had you to return the previous month's envelope unopened, and presumably you'd have some explaining to do if it wasn't sealed.