Almost all computer systems and devices come equipped with a Firewall (or many other similar programs with a variety of names such as "Lavawall", "Icewall", "Thunderwall", etc.) which serve a basic function of screening unauthorized traffic in, while still allowing regular outgoing communications. For most, this level of protection suffices, especially when combined with active monitoring by dedicated information security technicians or onboard AI. But for many military systems, the risks of hacking offer too much to leave to conventional, low-level systems. Such systems were used before The Fall, but the TITAN systems often found other ways to bypass these protections, or were simply not deterred by the additional countermeasures of military firewalls - which led to their use being limited afterword, and almost exclusively resigned to use by governing bodies, even private individuals have a hard time acquiring these so-called "Attack Barriers".
Attack Barrier: Known also as a military-grade Firewall, or sometimes referred to colloquially as a "backfire wall", the Attack Barrier is a sophisticated, nasty piece of software which is regulated basically anywhere that has regulations. The system integrates sub-AI Expert Systems and a modular codebase to increase efficiency and difficulty to probe. Some are even heuristic or self-modifying, even deliberately forming small exploits for a moment, only to close them shortly after. This automatically applies a -10 penalty on InfoSec tests to bypass the Firewall of a protected system. But the real prowess (and danger) of an Attack Barrier happens if a hacker fails to properly bypass the system. Failing to break an Attack Barrier almost always results in the Barrier logging the hacking attempt, at which point the system automatically counterattacks. Wireless intruders are subject to a trace and counterintrusion (see p. 258 EP) with an Attack Barrier's built in skillsofts counting as Research and InfoSec of 40. Failure to trace or counter-intrude will have the system log appropriate recommendation to perform a wireless termination or reauthentication. More dangerous for a hacker, however, is what Attack Barriers do to wired connections. The attack barrier system produces a potent electrical feedback in the area of intrusion, such as access jacks or conductive surfaces in case of Skinlinks, which causes 1d10+5+Shock DV to the person or device plugged into the system, ignoring Armor Value. While intended to incapacitate the hacker, this also commonly has the effect of damaging or disabling the physical access point used by the hacker. [Moderate]
Despite their uses, Attack Barriers are fairly rare outside of government computer systems, and as noted are highly regulated by most local laws - which often limit their powers. Attack Barriers used by the Titanian Commonwealth, for instance, have particularly sophisticated tracing and counterintrusion properties, grafted from their own top InfoSec experts, but their barriers are almost all secured in hardware which is physically incapable of using the shock functionality (at least, officially). In the Planetary Consortium, hypercorps with controlling interests in habs or corp stations are allowed to utilize these softwares, but rarely do so because of the harm they inevitably cause to their own hardware - preferring to use indentures or shackled AGI for active security. A topic common in LLA legislation is if Lunar banks may be allowed to employ Attack Barriers to safeguard the electronic systems which govern bank security, which has yet to pass. Before the Fall, Attack Barriers were actually most common on military vehicles, intended to protect from unwanted hacking while still allowing normal network functions - but due to this making subverted vehicles all the more hard to retake, this use of them has almost universally been stopped. Even still, rumors persist of government operatives using them in their own Cyberbrains, a nasty surprise used by many a counterterrorism or undercover operative.