Anticipating Security Threats to a Future Internet FORWARD Consortium: H. Bos (VU Amsterdam), E. Jonsson (Chalmers University), E. Djambazova (IPP-BAS), K. Dimitrov (IPP-BAS), S. Ioannidis (FORTH), E. Kirda (Institue Eurecom), and C. Kruegel (Technical University Vienna) Email: [email protected], [email protected], {ead,kpd}, [email protected], [email protected], [email protected] One of the most critical problems on today’s Internet is the lack of security. This gives rise to a plethora of different ways in which the confidentiality, integrity, and availability of data is compromised,and it provides a fertile breeding ground for a thriving underground economy. Thus, when designing afuture Internet, it is clear that security must be a first-class design consideration.
To be able to design security for a future Internet, it is first necessary to obtain a thorough under- standing of the threats and adversaries that the system must defend against. As a first step toward thisunderstanding, we introduce a number of emerging security threats that need to be considered. Thesethreats were identified by the three working groups that are active in the context of the EU FP7 projectFORWARD, and they illuminate different aspects of the threat landscape.
Keywords: Emerging Threats, Requirements Analysis, Future Internet George Santayana famously pointed out that “those who cannot remember the past are condemned torepeat it” [23]. Clearly, this advice is relevant when confronted with the task of inventing and designing afuture Internet. In particular, the quote indicates that one should study the current Internet, building uponsolutions that proved successful and avoiding those that turned out to be problematic.
One of the most critical problems for the Internet today is the lack of security. In fact, the rise and prevalence of malware [9], online fraud [5], denial of service attacks [17], and spam [20] give clear testimonythat the current Internet infrastructure provides no solid basis upon which effective security solutions canbe built. The reason for this problem lies in the original design of many core Internet protocols and net-work architectures, which were created without security considerations in mind. Combined with the knowndifficulties of retrofitting legacy systems with security, users are left with patchwork solutions that counterindividual threats, but fall short when attackers come up with yet another way to break the defenses. Thus,we firmly believe that a future Internet must have security built in from day one. This belief is also sharedby the creators of the recent US NSF initiative GENI, which funds research to develop clean-slate redesignsof the Internet [19].
While it is widely recognized that the future Internet requires built-in security mechanisms, the func- tioning of these mechanisms is less clear. In addition, and equally problematic, the adversarial model isnot well understood. That is, while the current problems are known, it is not obvious which threats a fu-ture Internet must be armed against. However, identifying the adversarial model and anticipating emergingthreats is the first step that is necessary to build a secure, future Internet. Only when the community has asolid understanding of the threats that the future Internet might face, appropriate countermeasures can bedesigned.
In this paper, we take a first step towards establishing an adversarial model for the future Internet. To this end, we introduce a number of emerging threats that should be taken into account when developing thedesigns of a future Internet. These threats and challenges were identified through the combined efforts ofthree working groups that operate within the framework of the EU F7 project FORWARD. The three projectworking groups look at different aspects of the ways in which we expect that a future Internet will be used, and threats that endanger these use cases. Thus, the threats that are identified by the groups are generaldevelopments that any future Internet design must likely address.
The first working group focuses on malware & fraud. This reason for selecting this problem area stems from the belief that the future Internet will continue to be used for e-commerce and financial transactions,even increasingly so. Combined with the fact that we witness the formation of a thriving undergroundeconomy, we expect significant opportunities for malicious code and scam operations that abuse victims forfinancial profit. The second working group focuses on threats that are due to the transformation of regularnetworks into smart environments. With this, we mean the increasing number of small devices that haveincreasing computing power. These small devices will soon be present everywhere and connected permanentlyto the Internet. Thus, a future Internet design has to address threats that are caused by the explosion ofubiquitous, small devices. Finally, we predict that the Internet will be increasingly used to control criticalsystems. While this often refers to the control of critical infrastructure and industrial plants, this is onlypart of the picture. The reason is that also software systems can carry out mission-critical tasks, and lossor disruption of connectivity or software failures can cause severe economic damage or threaten lives. Thus,a future Internet has to address the threats that come along with the increased reliance on a functioning,underlying network infrastructure.
In the following sections, we discuss key threats that have been identified by the three working groups and argue that they are relevant for the design of a secure, future Internet.
In recent years, we have witnessed a dramatic change in the goals and modes of operation of malicioushackers. As hackers realized the potential monetary gains associated with Internet fraud, there has been ashift from “hacking for fun” (or bragging rights and celebrity within and outside the hacker community) to“hacking for profit.” This shift has been leveraged and supported by more traditional crime organizations,which eventually realized the potential of the Internet for their endeavors.
The integration of sophisticated computer attacks with well-established fraud mechanisms devised by or- ganized crime has resulted in an underground economy that trades compromised hosts, personal information,and services in a way similar to other legitimate economies. This expanding underground economy makes itpossible to significantly increase the scale of the frauds carried out on the Internet and allows criminals toreach millions of potential victims. Also, criminals are taking full advantage of sophisticated mechanisms,such as the service bots used on IRC channels to automatically verify stolen credit card numbers, the use ofe-casinos to launder money, and the use of fast-flux networks to create attack-resilient services.
Many of the problems related to malware and fraud are rooted in the poor security of the end hosts and the gullibility of end users. However, some of the attacks take full advantage of the poor security of theInternet infrastructure and its protocols. In those cases, as discussed below, a future Internet design canplay an important role to mitigate the threats.
The network infrastructure (such as switches and routers) and network protocols (such as IP and routingprotocols) provide the means for remote hosts to exchange packets. Unfortunately, these protocols and theinfrastructure offer basically no security. As a result, packets between hosts can be easily intercepted andaltered. Incorrect routes can be injected, a practice that is frequently used to send untraceable spam or tocause denial of service attacks. Moreover, there is no accountability, allowing a sender to spoof the origin(source address) of packets.
Of course, there are many different techniques that address parts of the problem. For example, crypto- graphic solutions can help to maintain the confidentiality and integrity of application data, security enhance-ments to BGP (such as sBGP) were proposed to defend against the injection of fake routes, and filtering atthe network perimeter can help against packet spoofing. However, the problem is that these solutions areonly add-on patches that address a small aspect of the problem. In addition, many solutions are not widely-deployed. For example, sBGP is barely used and the routing infrastructure remains vulnerable. Often, thereason for not upgrading is the high cost of changes to the infrastructure, and little incentive because abuseand fraud often do not affect the provider of the infrastructure but end users.
Higher-level protocols must be able to rely on a secure and robust underlying architecture. Thus, we claim that it is imperative to build accountability into a future Internet. Accountability must ensure thatpackets and actions can be reliably connected to the originating source. In this fashion, it is possible toidentify culprits, block their activity, and also use recorded information as evidence for legal actions. Thisis an important step to prevent criminal activity that can rely on the anonymity and untraceability thattoday’s infrastructure provides.
In addition to the basic Internet routing and network infrastructure, many Internet applications rely onthe existence and correctness of the domain name service (DNS). DNS is a protocol that resolves human-readable names (URIs) to IP addresses. While crucial for the proper functioning of the network, DNS isunfortunately very insecure. This has led to a number of problems in the past, where attackers alteredthe mapping between a domain name and the corresponding IP address(es), redirecting legitimate trafficto malicious hosts or launching man-in-the-middle attacks. Such cache poisoning attacks were less frequentover the last years, but experienced a dramatic renaissance with the discovery of the Kaminsky bug1.
Besides the security problems of DNS itself, the protocol is also heavily abused for fraud and botnet operations. One particular problem is fast-flux, and the role that domain registrars play in this scheme.
Fast-flux is a DNS technique that is often used by criminals to hide scam and malware delivery sites behindan changing network of compromised hosts that act as proxies. More precisely, with fast-flux, criminalsregister a domain name and frequently change the mapping between this domain name and multiple IPaddresses. These IP addresses typically belong to bots that act as proxies. When a victim resolves theaddress that belongs to a malicious domain name, he will contact one of the bots. This bot will thenforward the traffic to the actual server that is controlled by the criminal (this server is often referred toas the mothership). By inserting an additional layer of proxies between the victim and the mothership, itbecomes much harder to locate a malicious host and take it down. Instead, only the IPs of compromisedmachines (bots) are visible, and these IPs can be quickly changed when a bot-infected machine is cleanedup. In addition to hosting fast-flux networks, criminals also frequently register hundreds or thousands ofthrow-away domains that are used to advertise scam sites in spam mails. In both cases, domain registrarsplay an important role. With fast-flux, attackers have to frequently change the IP addresses that belongto a domain name, an activity that is highly unusual and suspicious in normal operations. When criminalsmanage to register many domains, it is also evident that registrars do not put sufficient checks into place toprevent abuse.
Clearly, the Internet requires a lookup service that allows hosts to securely locate remote resources.
However, the current DNS approach is not working. Thus, the future Internet requires a robust and securelookup service that is resilient to the injection of invalid mappings. This would prevent cache poisoningattacks and fast-flux networks, since it would no longer be possible to map a domain name to a host thatis neither authorized nor aware of this mapping. Moreover, the mechanism to register names has to beoverhauled.
Spam originally referred to the canned meat product sold by the Hormel Foods Corporation. Since then,many other uses of the term have emerged. With respect to security, the term spam denotes unsolicitedmessages sent to a large number of Internet users with the aim of luring them to specific web sites. Thesesites are often used by the spammers to sell products. These products may be illegal, or difficult to obtainvia normal means (e.g., a popular product that is often endorsed by spam messages is Viagra – a pill thatneeds to be prescribed by a doctor). However, in some cases, miscreants also attempt to install maliciousapplications on the computers of the victims that visit the web site.
Although Internet spam is typically identified as being unsolicited, “bulk,” or “junk” e-mail messages, spammers have been finding new ways of delivering spam messages to Internet users. By diversifying thedelivery vectors with the aim of reaching as many Internet users as possible, spammers wish to increase 1A bug in the design of DNS, which was discovered by Dan Kaminsky and which allows attackers to inject incorrect mappings their chances of luring visitors to the web sites that they advertise. Another reason for the diversificationand discovery of novel spam delivery protocols is that e-mail-based spam filters have improved considerablyover the last years. Hence, the chance of an e-mail-based spam reaching a user is lower now than spam thatis being sent over other protocols (such as instant messaging). In fact, spammers have been increasinglymaking use of instant messaging protocols such as Skype and MSN to send unsolicited chat messages tousers. Such messages are usually more difficult for the users to block. Instant messaging products usuallydo not provide sophisticated filtering mechanisms to identify and eliminate spam messages. For example, itis quite common for ICQ users to receive chat messages in Russian that contain URLs of possibly maliciousweb sites.
In the future, it will be very important for all communication protocols used on the Internet to enable and support filtering and authentication mechanisms. In fact, spam messages are only possible because thesender cannot be authenticated and identified in many protocols (i.e., the sender can often be forged).
Novel communication protocols are also interesting with respect to security because of the threat of botnets. The term botnet refers to a collection of software robots, or bots, that run autonomously. The termis often associated with malicious software. A miscreant, often called “botmaster” or “botherder”, controlsa set of bot-infected machines remotely. The power of botnets lies in the fact that bots are usually runningon personal computers of unsuspecting victims. Hence, to an outsider, the Internet IPs of these machinestypically appear legitimate and difficult to tag as being malicious.
The majority of botnets are controlled via IRC (Internet Relay Chat). That is, the bots log on to specific IRC channels that have been designated by the botmaster and wait and listen for incoming commands.
Although IRC is simple and efficient to use from the attacker’s point of view, it is also easy to disrupt andtake down. As a result, miscreants have been building botnets that rely on different protocols to implementtheir command and control infrastructure. For example, P2P protocols such as Gnutella have becomepopular. A botnet that uses P2P as its command and communication infrastructure is more resilient andmore difficult to take down.
In the future, botnets will probably also use other forms of command and control infrastructures that are more stealthy and efficient. For example, there is a chance that future botnets may communicate oversocial networks, blending the control communication with legitimate user communication. Thus, designersof future communication protocols must be aware of the fact that their protocols will be misused to deliverunsolicited messages to users, and that they can be misused to control botnets. The challenge is to introducemechanisms to prevent these types of misuse and to add accountability that allows one to identify, block,and remove people (or hosts) that abuse these networks.
The nature of devices connected to the Internet is changing. In addition to traditional computer equipment,smartphones, PDAs, security cameras, and different sorts of other sensors now latch onto a common infras-tructure. As a consequence, new security threats arise. In this section, we discuss threats related to smartphones and ubiquitous sensors, all accessing and using a common Internet infrastructure.
Smartphones are mobile phones with PC-like capabilities. In addition to more traditional telephony stacks,calendars, games and address books, they may run any application the user loads onto them. An increasingnumber of hardware vendors release ever more powerful models, running a variety of applications on a diverseset of operating systems. The application domain of smartphones currently ranges from high-end businessmarkets (targeted, for instance, by RIM’s Blackberry) to consumer and entertainment markets (as targetedby the Apple iPhone, HTC’s implementation of Android, and Nokia 5800 series). In practice, smartphonesare used for email, web browsing, centralized calendaring, navigation, music, etc. In addition, phonesare frequently used for commercial transactions. Apple and other companies allow applications, music andvideos to be purchased online. Payment for goods and services via mobile phone is already provided by UpaidSystems and Black Lab Mobile. In the meantime, companies like Verrus Mobile Technologies, RingGo, EasyPark, NOW! Innovations, Park-Line, mPark and ParkMagic all offer payment-for-parking schemes. Others focus on mass-transit. For instance, Mobile Suica already allows passengers to use their mobile phones topay for transport on the East Japan Railway Company, the largest passenger railway company in the world.
It is clear that the domain is widening and that it involves money. Analysts predict that in the near future, smartphones will be the primary interface to the Internet and, indeed, the digital world in general.
The tsunami of applications engulfing what was previously a “dumb” device (a phone) implies that bugs andvulnerabilities to attacks are on the rise as well. Vulnerabilities provide opportunities for attackers, while theincreasing importance of smartphones, and the real money involved in the interactions, provide an incentive.
Vulnerabilities in the past have allowed attackers to completely take over mobile phones via Bluetooth.
Examples included phones from various vendors, such as the Nokia 6310, the Sony Ericsson T68, and theMotorola v80. The process, known as bluebugging, exploited a bug in the Bluetooth implementations. Whilethese are fairly old phones, more recent models, such as the Apple iPhone have also shown to be susceptibleto remote exploits So what is new? Surely, we have seen all of this before in the world of PCs and so the threat of the future is the threat of today? Unfortunately not. Yes, smartphones are just like PCs in processing capacity,range of applications, and vulnerabilities to attacks. But they are very unlike PCs in other respects, notablypower and physical location. These two aspects matter when it comes to security.
First, unlike normal PCs, smartphones run on battery power. Power in mobile phones is an extremely scarce resource. For instance, one of the main points of criticism against Apple’s iPhone 3G is its shortbattery life [18]. Software developers bend over backward to make core code run fast on phones, becauseevery cycle consumes power, and every Joule is precious. As a consequence, many of the security solutionsthat work for desktop PCs do not suit smartphones, simply because they are too heavyweight. File scanning,taint analysis, system call monitoring all consume battery power. Battery life sells phones, and consumerhate recharging. The likely result is that both vendors and consumers will trade security for battery life.
Second, unlike traditional computers, phones go everywhere we go. Attacks may come from sources that are extremely local (e.g., via bluetooth). A person with a laptop or another smartphone that happens to bein the same room could be the source of an attack. That means that security solutions based on in-networkscanning are insufficient: they will never even see the bytes that are used to take over the phone, stealinformation, and plunder the bank account. Worse, phones are small devices, and we do not always keepan eye on them. We may leave them on the beach when we go for a swim, slip them in a coat or shoppingbag, forget them on our desks, etc. Theft of a phone is much easier than theft of a desktop PC or even alaptop. Moreover, attackers could “borrow” the phone, copy data from it, install backdoors, etc. This is animportant difference compared with the PC you have sitting on your desk.
What would it buy an attacker to steal a phone (and perhaps return it later)? Almost always, having physical access to a device opens up a wide range of attack options, for example, hardware attacks [6].
Attackers may use hardware debugging equipment to snoop on data traveling from and to memory, read orwrite keys, etc. Direct loss of private data may be an immediate result. However, another and perhaps moreinsidious threat is when the phone is returned to the owner with a backdoor that allow attackers to gatherinformation for a long period of time.
Is this practical? Let us have another look at the example of bluebugging; the faulty implementation that made the earliest bluetooth phone vulnerable to remote exploits was fixed fairly quickly. However, phonescould still be compromised. The only thing that was needed was that the bluebugger talked ‘the victiminto handing over the phone, which the bluebugger manipulates to set up a backdoor attack and then handsback’ [14].
We stress that the trends are not working in our favor. On one hand, mobile phones are an increasingly attractive target for attackers. On the other hand, because of power limitations and physical exposure tohostile environments, phones are inherently more difficult to protect than traditional computers. In a futureInternet, it is imperative that solutions are found to protect mobile devices that carry valuable data. Existingparadigms, based on in-network scanning and/or traditional anti-virus software cannot be simply ported tomobile phones.
What were you doing in the Red Light District? Last month’s parking sensors indicate that your car was parked on a Saturday in the Red Light District inAmsterdam. Your mobile phone was seen wandering up and down the seedier streets of Amsterdam for a while before stopping in one place for a good 20 minutes. When finally roaming again, it made a beelineto the Warmoesstraat where several bluetooth devices interacted with it during a 60-minutes interval at alocation known to accommodate a (Dutch-style) coffee shop.
This is not (yet another) story about violation of privacy, or “Big Brother is watching you having a day of R&R in Holland.” Although the threat of privacy violation cannot be overstated, it is hardly new andwe will not address it in this paper. While it may have been painful for you to be spotted in compromisinglocations on a day that you claimed to be going for a walk on the beach, we worry about something elseentirely: were you really there? Or, to what extent can we trust sensor data connected on to the futureInternet? Buggy devices yield wrong information. A common example of a buggy sensor is the barcode reader in the supermarket that double-charges a product. Similarly, supposedly-disabled RFID tags on clothingor other products frequently set off alarms when a client exits the shop, often creating embarrassment. Ithas happened to most of us, and these are the simplest examples of what we call buggy devices. Whilebarcode readers result in modest overcharging, other types of buggy sensors are more serious. In someplaces, automated parking sensors are used to identify your car, and cars are tracked on motorways to pay-as-you-go. In several countries, public transport is accessed using a smart card or phone, directly linkableto you. With the increase of the number of sensors increases the probability of false reports.
Similarly, as Internet Protocol (IP) telephony becomes ever more popular, buggy telephones (or buggy call protocols) may dial arbitrary numbers without the user’s consent. Many companies base their revenueon received phone calls as they have special contracts with telephone companies. A buggy device may endup benefiting the company and harming an unaware user. Apart from the financial aspect of the issue, amore important aspect arises. If the buggy telephone can call anywhere, it means it can place calls to peopleyou might not want or should call. For example, an employee in a large company owns a buggy telephone.
What will happen if his company finds out that he calls phone numbers belonging to a competitor? It isunclear whether he will be able to convince their employers that something went wrong.
Perhaps the most significant threat is that data can be falsified. Most information is stored in centrally-controlled databases. This is a fact that can be hardlychanged, as distributed control costs both in terms of resources and manpower. Take, for example, yourtelephone company. Whether you are at home or roaming away from it, all your phone calls are loggedby your provider in a huge, centralized repository. A sophisticated hacker or a person with knowledge of acompany’s internals can alter all the information about your phone calls. Such actions can have significantrepercussions in one’s life. For example, one may be framed by being linked via telephone records to criminals.
Mobile tracking, shopping activities, car parking, they all can be manipulated to create a virtual clone ofyourself with unknown implications. In the digital world, where everything is connected via the Internet,planting of “evidence” is both easier to do and harder to detect.
Apart from relatively harmless issues, the implications of sensor and database hacking can be very harmful, even lethal. We have sensors and databases in hospitals, in banks, in organizations, in policeand justice departments. Given the proper motive, a person with access to such information can easilyincriminate or even kill someone. An example is that of medical records. A patient enters a hospital aftera serious car accident, far away from their home. The hospital doctors consult the e-record to check thepatient’s medical history. The original medical record indicates a blood allergy to specific drugs. An alteredmedical record hides this information. Wrong treatment to the patient can be lethal, and it is very probableto happen as the medical history can be totally changed.
Legal implications. In our opinion, the untrustworthiness of sensor data creates a legal void that needs to be filled urgently. All easy solutions are wrong. Admitting sensor data as reliable proof makeslittle sense if the data may be unreliable, and especially if the data can be altered. But clearly, there is alink between the sensor data and reality in most cases, so we cannot dismiss sensor-based evidence either.
Current legislation already looks at some of these issues (e.g., the legal status of footage from a surveillancecamera), but the scale at which a multitude of sensors will track persons and objects in the future is suchthat re-thinking legal implications is important. The issues that need to be taken into account ranges fromevidence based on individual sensors to collections of sensors, and incorporates both agreements betweensensors and anomalies. Arguably the most important question that needs to be answered is how people whoare accused on the basis of sensor data can defend themselves. Here, a future Internet design is again askedto provide data provenance, a mechanism that allows one to securely track the origin of data, as well as modifications to this data. While this might not prevent all misuse, it allows one to go back and track thoseresponsible for malicious activity.
The Internet is a communication environment that has become an essential part of our everyday life, in thesame fashion as the electricity or the telephony network have become essential over the last one hundred years.
The more products and services we access through it, the more dependent we become on its functionality andavailability. Indeed, the “functionality” of the Internet has outgrew its initial goal, to transfer informationbetween distant sites; we now expect it to transfer trust and to operate in new critical areas.
The complexity and interdependence of modern inter-networks make identifying threats that impede their proper operation extremely difficult. Covering all possible individual threats would be impractical inthe context of this paper, so we will focus on the probable areas of occurrence of threats and outline the mostsensitive points of emerging threats that have the potential to endanger critical systems (CS). We believethat covering such threat areas will assist researchers, manufacturers, and the community as a whole, tofocus their efforts.
By design, the Internet is not suited for critical applications, since it was built to provide a best-effort packet relay service. Having outgrown its intended purpose, the Internet is now being used by criticalapplications, and, as a result, it has itself turned into a critical system. The popularity and mass expansionof the Internet encourages its use even in critical applications where it was not previously used. The Internettechnologies work along with the specialized technologies for process control and if this tendency reaches thesafety-critical systems in their main functionality, it could be a serious threat.
Another area of potential threats is the connection of the Internet to critical infrastructures (CIs). Many CIs (e.g., banks, power stations, industrial complexes, telephony networks, etc.) use the Internet for theircommunication needs. The problems of Internet’s insecurity and vulnerability increase when considering thescale, complexity, connectivity, and interdependency of such critical infrastructures.
Penetration of the Internet in the economic sectors of our society poses considerable risks. So, what arethe emerging threats from such use? Answering this type of questions will assist us in understanding therelationship between the Internet and critical applications.
Traditionally, in the fields of hazardous industrial processes and safety-critical systems for process control, specialized real-time and fault-tolerant computer systems and communications are used with guaranteeddependability and safety.
On the other hand, according to the integrated vision on dependability and security [3], any undesired event for a system (external or internal) can be regarded as a threat. For example, if an off-the-shelfsystem is put in a critical application, there is high probability that a fault occurrence may lead to systemfailure with unpredictable consequences. Fault-tolerant systems preserve their dependabilty and securityeven when unreliable components and subsystems are used for their design. Unfortunately, such guaranteesare not present in the Internet. In particular, the use of off-the-shelf components in the Internet is a commonpractice. Hence, when used in critical applications, problems can arise.
A possible chain of threat-causing events (threat pathology) could be as follows: (i) The use of the Internet into a critical application induces a gap between the application requirements and the capabilities of theinvolved Internet components, (ii) this deficiency effectively decreases the robustness of the components and(iii) in turn leads to increased risk and vulnerabilities. Therefore, the increasing and uncontrolled use of theInternet in critical systems can be regarded as an area of emerging threats in itself.
To reduce costs and time for design the use of Commercial Off-The-Shelf (COTS) systems and components in critical applications is attractive and will continue. To avoid the above threats, their deficits have to becompensated for.
There are some projects (e.g., [1]) where COTS components are applied to design distributed computer- controlled systems. They are organized using redundancy and design diversity to make the system dependableand secure. Some of the issues addressed in DEAR-COTS are the use of emerging information technologiesto cope with heterogeneity issues while providing a dependable user-friendly man-machine interface.
Another direction is to apply COTS and open source standards along with the standards for process control systems. The organizations from industry that develop commercial interface standards work withsome military programs to include real-time and fault-tolerance requirements to critical systems [8].
Although it is not applied directly to control critical industrial processes, there are systems that use the Internet technologies and Ethernet to facilitate the access of operators or other maintenance personnel tothe control system. That is especially convenient for distributed process control systems where the nodesare distant and their surveillance is done remotely. Process control systems operate with their own protocolsand communication channels that are not compliant with the Internet. The control process is independentof any outside activity. The control system is decoupled from other general-purpose systems and networks.
The access to the controlled object is left to the controlling system alone. There is a trend, however, to usethe flexibility and connectivity of the Internet in so called Internet-based control systems [24], [16]. Specialattention must be paid to security and safety of such systems [13].
In an overview of incident and vulnerability trends [2], CERT/CC enumerates the most probable threats inthe Internet after 2003. Although that prediction may seem old (by Internet standards), it is still relevant fortoday’s state-of-practice. That is, the basic effects of an attack, the attacking methods and opportunities, themajor threats are almost the same. The only changes have occurred in their scale. It is interesting to analyzesome of the challenges that CERT outlined that relate to critical systems, since these problems persist andare amplified. In particular, some of the conclusions in that overview are now reality. The complexity ofthe Internet, protocols, and applications is increasing along with our reliance on them. Moreover, criticalinfrastructures increasingly rely upon the Internet for operation. The attacks become more severe and canlead to monetary/financial loss or even loss or endangerment of human life. The adversary increases theimpact by targeting the infrastructure. The opportunities for intrusions grow. The problem is that thefundamental security design difficulties cannot be addressed quickly, and despite the security tools available,the complexity and growth of the network can outpace our capability for defense.
One of the critical issues in the critical infrastructures is the interdependencies among the infrastructures.
In [22], the role of ICT technologies in CIs is defined with the term cyber interdependency. An infrastructurehas a cyber interdependency if its state depends on information transmitted through the information infras-tructure. Virtually all modern infrastructures are dependent on the security of information infrastructure.
Given the extensive cyber interdependencies, one has to prepare for the amplification of the security risks.
Being part of the communications infrastructure, the Internet has the same typical vulnerabilities and is prone to similar threats. There are approaches to improve communications’ robustness and availability(and those of the Internet in particular) [25]. Using the Eight Ingredients Framework of CommunicationsInfrastructure [21], the vulnerabilities of future networks were studied systematically to determine the vulner-abilities of each of the eight ingredients. The approach relies on vulnerability analysis, since it is recognisedthat intrinsic weaknesses of communications infrastructure are a finite number and can be identified by theprofessionals in order to eliminate or mitigate their effects. Combining vulnerability and threat analysis willhelp improving CI security. Although it is argued that threat analysis is ineffective when the knowledge ofpossible threats is not certain, the identification of threats helps anticipating challenges in areas of concernthat may need more research and development activity.
As the use of the Internet in critical applications and CIs in the near future is unavoidable, the followingmain suggestions could be considered: 1. Make a full decoupling of highly-critical systems (hazardous industrial processes, mission-critical tasks) 2. Control the introduction of the Internet in other critical areas (legislatively, technically and organiza- Some measures related to the second suggestion may be: (a) surveillance, regulation, and coordination between different sectors of CIs in the cases when they are planning the use of the Internet, e.g. like these in [11]; (b) application of diversity approach when using COTS components [4]; (c) use of compact and trustedapplications base; (d) use of integral approach to security (e.g., [12]).
As stated previously, the emerging and future threats are hard to identify, so this may be an unfeasible task. There are many threats that still remain and will be unidentified. At the same time, we can say muchmore about the stochasic nature of security challenges. The times of occurrence of the challenges that couldaffect normal operation will rapidly and arbitrarily differ and shall be likelihood uncorellated. Moreover,new challenges will emerge (e.g. new application traffic loads, forms of distributed denial of service (DDoS)attacks, deployment environments, and networking technologies). As a consequence, the affected informationinfrastructures and delivered network services will change unpredictably. This makes unusable a set ofscenarios for resilience prepared in advance and imposes the use of a dynamically reconfigurable and extensibleinfrastructure with context awareness capabilities. Another challenge is that often a sufficiently sophisticatedDDoS attack is indistinguishable from legitimate but enormous traffic (e.g. flash crowd events) [15].
Resilience approach (RA) [4], [10] is a feasible, emergent, and integral approach that can be used for managing the emerging threats. To be successfully implemented, systems and networks have to be designedand built with RA in mind and used in compliance with RA concepts. The main idea is creating a newkind of Information Society Technologies, the resilient technologies [4], that will have and demonstrate anemergent behaviour to successfully withstand and cope with the emergent and arbitrary behaviour of thechallenges to normal operations.
Another direction to anticipate the challenges to the future Internet is to develop new architectures that can foster innovation, enhance security and accountability, and accommodate competing interests.
Postmodern Internet Architecture [7] aims at developing internetwork layer and auxiliary functionality thatoperate in policy space as opposed to the current Internet functionality. The overall goal of the project is tomake a larger portion of the network design space accessible without sacrificing the economy of scale offeredby the nowadays unified Internet.
In this paper, we have outlined different, emerging threats that the Internet faces today. While we havenot proposed any concrete, technical solution to a problem, we believe that it is important to study andunderstand these threats as a first step to be able to build a better future Internet. As with all engineeringprojects, requirements analysis is the crucial first step. By analyzing emerging threats from different angles,we hope to provide such a requirements analysis. This can help to ensure that a future Internet does notrepeat the mistakes that were made in the design of the current protocols and infrastructure.
[1] DEAR-COTS Project Homepage., 2001.
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