The internet is an interconnection of millions of individual computer networks owned by governments, universities, nonprofit groups, companies and individuals. While the internet is a great source of valuable information and entertainment, the internet has also become a major source of system damaging and system fatal application code, such as “viruses,” “spyware,” “adware,” “worms,” “Trojan horses,” and other malicious code.
To protect users, programmers design computer and computer-network security systems for blocking malicious code from attacking both individual and network computers. On the most part, network security systems have been relatively successful. A computer that connects to the internet from within an enterprise's network typically has two lines of defense. The first line of defense includes a network security system, which may be part of the network gateway, that includes firewalls, antivirus, antispyware and content filtering. The second line of defense includes individual security software on individual machines, which is not typically as secure as the network security system and is thus more vulnerable to attacks. In combination, the first and second lines of defense together provide pretty good security protection. However, when a device connects to the internet without the intervening network security system, the device loses its first line of defense. Thus, mobile devices (e.g., laptops, desktops, PDAs such as RIM's Blackberry, cell phones, any wireless device that connects to the internet, etc.) when traveling outside the enterprise network are more vulnerable to attacks.
FIG. 1 illustrates an example network system 100 of the prior art. Network system 100 includes a desktop 105 and a mobile device 110, each coupled to an enterprise's intranet 115. The intranet 115 is coupled via a network security system 120 (which may be a part of the enterprise's gateway) to the untrusted internet 130. Accordingly, the desktop 105 and mobile device 110 access the internet 130 via the network security system 120. A security administrator 125 typically manages the network security system 120 to assure that it includes the most current security protection and thus that the desktop 105 and mobile device 110 are protected from malicious code. Demarcation 135 divides the trusted enterprise 140 and the untrusted public internet 130. Because the desktop 105 and the mobile device 110 are connected to the internet 130 via the network security system 120, both have two lines of defense (namely, the network security system 120 and the security software resident on the device itself) against malicious code from the internet 130. Of course, although trusted, the intranet 115 can also be a source of malicious code.
FIG. 2 illustrates an example network system 200 of the prior art, when the mobile device 110 has traveled outside the trusted enterprise 140 and reconnected to the untrusted internet 130. This could occur perhaps when the user takes mobile device 110 on travel and connects to the internet 130 at a cybercafé, at a hotel, or via any untrusted wired or wireless connection. Accordingly, as shown, the mobile device 110 is no longer protected by the first line of defense (by the network security system 120) and thus has increased its risk of receiving malicious code. Further, by physically bringing the mobile device 110 back into the trusted enterprise 140 and reconnecting from within, the mobile device 110 risks transferring any malicious code received to the intranet 115.
As the number of mobile devices and the number of attacks grow, mobile security is becoming increasingly important. The problem was emphasized in the recent Info-Security Conference in New York on Dec. 7-8, 2005. However, no complete solutions were presented.
Similarly, when a host device is connected to an external device such as a USB flash drive, iPod, external hard drive, etc., both devices are vulnerable to receipt of malicious code or transfer of private data. FIG. 11 illustrates an example prior art data exchange system 1100 that includes a host computer (host) 1105 and an external device 1110. The host 1105 includes a external device (ED) port 1115, such as a USB port, for receiving the external device 1110. The host 1105 also includes ED drivers 1120 for performing enumeration and enabling communications between the external device 1110 and the host 1105. The external device 1110 includes an ED plug, such as a USB plug, for communicating with the ED port 1115. Both of the host 1105 and external device 1110 are vulnerable to receipt of malicious code or transfer of private data.