In a recent attack on the Texas A&M computer complex, which consists of over 12,000 interconnected PCs, workstations, minicomputers, mainframes, and servers, a well-organized team of hackers were able to take virtual control of the complex. Having broken in by running password-cracking programs, the intruders then modified login software to enable them to capture additional passwords of users logging on to systems.

The team complied files containing hundreds of captured passwords, including some on major and supposedly secure servers. One local machine was set up as a hacker bulletin board, which the hackers used to contact each other, to discuss techniques and progress, and to disseminate the captured passwords. The team gained access to email servers, enabling them to capture and read mail traveling to and from dial-in personal computers used by staff, faculty, and students.

1. Vulnerability to attack is not limited to academic complexes. Virtually every private and public sector computer complex is connected to the outside world through the Internet or dial-in ports. Even "private" networks make use of microwave transmission or public telecommunications networks. Now is the time when network security is desperately needed.

Network and Internetwork Security covers network security technology, the standards that are being developed for security in an internetworking environment, and the practical issues involved in developing security applications. The first part of the book is a tutorial on and survey of network security technology. Each of the basic building blocks of network security, including conventional and public-key cryptography, authentication, and digital signatures, is covered.

In addition the first part explores methods for countering hackers and viruses. The second part of the book is devoted to a thorough discussion of important network security applications, including PGP, PEM, Kerberos, and SNMPv2 security.