The document summarizes the history of network security. It discusses how the ARPANET was first introduced in the 1960s-1970s. In the 1970s and 1980s, security was limited as internet usage was also limited. The first computer virus for IBM PCs was called Brain in 1983. Robert Morris created the Morris Worm in 1988, considered the first computer worm on the internet. John McAfee discovered the first antivirus software called Norton in 1991. Several major cyber attacks are mentioned such as Solar Sunrise in 1998 and the Melissa virus in 1999.