To address the aforementioned requirements, we clearly had to use a client/server database technology. To defend against eavesdropping, we had to encrypt all communications.
At the time, IPsec and virtual private networks were not available. Even today, these are young technologies and VPNs are not yet suitable for implementation on client workstations. The solution had to be encryption in the DBMS protocol. To do this, we could either buy Secure Oracle (which would put the project over budget), or roll our own solution.
We had to write a DBMS engine which would encrypt all communication, be responsive when the bandwidth was low and the latency high, support strong authentication, access controls and auditing features. On the bright side, we really didn't need an SQL engine, or a generalized query engine at all. (More on queries and reports later, though!)