Introduction to Cyber-Warfare - Proiect SEMPER FIDELIS

ESTONIA IS HIT BY CYBER ATTACKS17FIGURE 2.1 The Bronze Soldier of Tallinn. The relocationof this statue, which commemorates the Russianvictory against Nazi Germany in World War II, led to massivecyber attacks against the Baltic State by Russianhackers. Source: Petri Kohn via Wikimedia Commons. 24E-mail servers on the Internet are used to receiving unsolicited messages at continuous butmoderate pace. They use techniques from machine learning to classify incoming messages asspam or not spam. The purpose of this classification is entirely to lessen the irritation to humanusers of unsolicited messages. E-mail severs exist entirely to process incoming messages;therefore, if they are sent an overwhelming quantity of e-mail, they are generally unpreparedto deal with this in a graceful way. Which messages are part of the flood, and which messagesare illegitimate? The system would not know until it reads them all, and since computingpower is finite, the availability of e-mail servers can be negatively impacted by sending ita very large number of messages.On April 29, a flood of messages made the e-mail servers of the Estonian parliamentunavailable. This system would remain off-line for 12 h. What direct impact this had onthe government’s response both to the computer-based attacks and to the preceding riotsis unknown. It is not difficult to imagine that the unavailability of e-mail significantly impactedthe situation, especially given the lack of direct action that the government could taketo restore availability (Figure 2.2).This is a difference between electronic disruptions and physical disruptions: the sourceand means of a physical disruption can be identified. If protestors impede the availabilityof a road, clearing the protestors will restore access to the road. In the face of a flood of messagessent to an e-mail server, what means has the administrators of this server at hand torestore its availability? The source of the messages can be distributed across the entireInternet.