Data communication developments (1989-1994)
The FEL local area network (FELLAN) quickly expanded. We started using thin Ethernet to couple the LAN connections in the laboratory rooms. A considerable reduction in connection cost could be achieved (from 1200 to 400 Dutch guilders per connection).
At the end of 1991, we could install all LAN connections budgetary planned for that year and the two subsequent years. In order to keep possible technical network failures local as well as to keep the traffic as much as possible local on one’s own segment, the repeaters between the main FELLAN segments were replaced by security-enforcing bridges and routers.
Further FELLAN refinements took place in the course of 1994 when the strict network separation between the classified network parts was even more enforced and monitored. The FELLAN, however, allowed to provide central backup services for classified workstations.
Highly secure DES encryption
Early 1990, as part of a security evaluation project, the TNO-FEL obtained three Digital Equipment (DEC) DES encryptor units for the secure encryption of LAN traffic. Obtaining the required US export licences took a lot of paperwork and many months of administrative processing time. When DEC delivered and installed the table top units, it was decided to convert the units into a rackmount shape and mount them in a standard 19-inch rack. The table top enclosure surrounding the unit had to be removed. The units were on temporary loan. As the units needed to be returned in their original form, it was decided to put the screws back in place.
Unfortunately, the screws were a few millimetres too long for this unforeseen configuration. They shortened the electronic boards of two of the three DES units. All bits were encrypted to ‘dark matter’: very safe, but unusable. To receive new boards required another one-month ‘red-tape’ export procedure. After this disaster, DEC decided to create a second version of the DES encryption box with shorter screws.