UNDERGROUND

X.25 networks. X.25 is a type of computer communications network, much like the Unix-based Internet or the VMS-based DECNET. It has different commands and protocols, but the principle of an extensive worldwide data communications network is the same. There is, however, one important differ- ence. The targets for hackers on the X.25 networks are often far more interesting. For example, most banks are on X.25. Indeed, X.25 underpins many aspects of the world's financial markets. A number of countries' classified military computer sites only run on X.25. It is considered by many people to be more secure than the Internet or any DECNET system.

Minerva allowed incoming callers to pass into the X.25 network – something most Australian universities did not offer at the time. And Minerva let Australian callers do this without incurring a long-distance telephone charge.

In the early days of Minerva, the OTC operators didn't seem to care much about the hackers, probably because it seemed impossible to get rid of them. The OTC operators managed the OTC X.25 exchange, which was like a telephone exchange for the X.25 data network. This exchange was the data gateway for Minerva and other systems connected to that data network.

Australia's early hackers had it easy, until Michael Rosenberg arrived.

Rosenberg, known on-line simply as MichaelR, decided to clean up Minerva. An engineering graduate from Queen- sland University, Michael moved to Sydney when he joined OTC at age 21. He was about the same age as the hackers he was chasing off his system. Rosenberg didn't work as an OTC operator, he managed the software which ran on Minerva. And he made life hell for people like Force. Closing up security holes, quietly noting accounts used by hackers and then killing those accounts, Rosenberg almost single-handedly stamped out much of the hacker activity in OTC's Minerva.

Despite this, the hackers – 'my hackers' as he termed the regulars – had a grudging respect for Rosenberg. Unlike anyone