2.4 Summary

In this chapter, we looked at how the history of Unix evolved from Multics to the system that it is today. With Unix, unlike with other operating systems, security was not added as an afterthought: secure multiuser operation has been a requirement since Unix was created. But our notion of what "secure operations" means has changed over time, and with those changes Unix developers have tried to keep pace.

Today, when the majority of Unix systems are effectively single-user workstations, Unix security depends far more often on code quality and administrative practices. That's good news, as it means that Unix is fundamentally securable. However, keeping a Unix system secure can be a lot of work.