"So, we have backups on an encrypted drive, which we can't access (authentication is done via our custom ERP software, which is down as well - in hindsight, a very bad idea). And the backups don't work. We can rebuild the DNS servers from scratch, and the records are probably still safely stored somewhere inone of the 3 different databases our ERP software uses, but we don't have an authentication key or the scripts used to pull the DNS domain / record information from the ERP system anymore. The API's are undocumented, and there's only one key that can access those records."
Elsewhere, they say that two years ago, they found they were unable to restore from backups...