SafeGuard LAN Crypt version 3.6x and above.
All supported operating systems
How much does the size of the database increase per user (replication)?
The increase of data per user is hard to predict, but generally it is between 4k and 10k, depending on the length of names and the size of the certificate (assuming one certificate and one key per user). An additional unknown amount of data is used by the database for index, status, etc.