Activity Report 2004

Laboratory of Cryptography and System Security (CrySyS)
Department of Telecommunications
Budapest University of Technology and Economics
www.crysys.hu

The laboratory has three types of activities: research, teaching, and maintaining industrial partnership. Following this classification, this report is divided into three parts.

Security in the world of ubiquitous computing

The vision of ubiquitous computing is to surround people with all kinds of embedded computing devices that could assist them in their everyday activity and make their life easier. In order to take full advantage of this new paradigm, it is expected that these devices will form networks through which they can communicate with each other and reach existing computing infrastructures such as the Internet. In many applications, devices will use wireless links; however, they will be unable to transmit to a large distance due to severe constraints on their available energy and bandwidth. These issues have generated much interest in a new generation of networking technology called multi-hop wireless networking. Examples for multi-hop wireless networks include sensor networks, mesh networks, and mobile ad hoc networks.

Since multi-hop wireless networks are of paramount importance for ubiquitous computing, we have focused our research on them. In particular, we worked on the following two topics: routing security and cooperation.

AZIMUTH - analyzing and designing secure routing protocols for multi-hop wireless networks

Routing is one of the most basic networking functions in multi-hop networks. Hence, an adversary can easily paralyze the operation of the network by attacking the routing protocol. This has been realized by many researchers, and several "secure" routing protocols have been proposed for wireless ad hoc networks. However, the security of those protocols have been analyzed either by informal means only, or with formal methods that have never been intended for the analysis of this kind of protocols. Our research revealed that many of the proposed protocols (e.g., SRP and Ariadne) are flawed in the sense that they do not achieve the properties claimed by their authors. We beleive that the main reason for this is the lack of a mathematical model in which rigourous definitions of security can be given and protocols can be proven secure (or not) with respect to these definitions. We addressed these problems by proposing a sound mathematical technique for the analysis of routing protocols. Our method is an adoptation of the simulation paradigm to ad hoc routing protocols. We demonstrated the usefulness of our approach by proposing a new on-demand source routing protocol, called endairA, and proving it to be secure in our model.

Researchers involved in this project: Gergely Ács (student), Levente Buttyán, and István Vajda

Publications: BV04sasn, A04tdk

INCOME - incentives for cooperation in multi-domain wireless networks

In multi-hop wireless networks, data packets are relayed by the devices (and base stations) in several wireless hops from their source to their destination. Hence, the proper operation of the network requires the devices to cooperate. If the devices belong to the same administrative domain, then they collaborate by default. This is the common situation in military and rescue applications. However, in many civilian applications, the devices fall into different administrative domains. In this case, cooperation between devices of different domains cannot be taken for granted, because it costs energy and it has no direct advantages. In fact, the devices (or their users) may tend to be selfish, and deny packet forwarding for the benefit of devices belonging to foreign domains in order to save their own resources. In this project, our goal was to study under what conditions cooperation can emerge spontaneously in the network. The emergence of cooperation between agents of conflicting interests has been observed in some biological, political, and social systems. The question we were interested in is: can this happen in wireless networks too?

Note: Some parts of this project has been carried out in collaboration with the group of Prof. Jean-Pierre Hubaux at the Swiss Federal Institute of Technology -- Lasuanne (EPFL).

Researchers involved in this project: Levente Buttyán, Tamás Holczer (student), Péter Schaffer (student)

Publications: BHS04ht, HS04tdk, FHB05persens, FHB05ieeetmc

Security of smart card applications

A smart card is a small plastic card with an embedded microchip. Regarding its capabilities, a smart card is a micro-computer: it can store and process data. However, compared to a traditional computer, smart cards are very easy to carry around. Smart cards have many possible applications. Due to their tamper resistance and computing capabilities they are often used in security applications, such as electronic ID cards, digital signature cards, access control to buildings, logon to a computer, electronic purse, SIM cards (for cellphones), pre-paid telephone cards, public transport e-tickets, pay TV applications, ... All in all, smart cards are becoming very widespread.

SMARTER - smart card applications and their security

The goal of SMARTER is to study various problems related to the safe usage of smart cards in security applications. In particular, we have studied the untrusted terminal problem, which stems from the fact that smart cards have no user interface, and hence, they are unable to communicate with the user directly. Communication is only possible with the aid of a terminal, which leads to several security problems. For example, the terminal may perform a man-in-the middle attack. Although the problem is widespread, it has relatively little literature. We have developed a solution which can alleviate the problem. It is based on a new concept called conditional signatures. We have also implemented a prototype of our proposal on Axalto Java cards.

Researchers involved in this project: István Zsolt Berta, Levente Buttyán, István Vajda, and Tamás Veiland (student)

Publications: BBV04itcc, BBV04cardis, BB04niif, BV05tatra

Internet security

• the identification of virus sources (owners of infected computers, virus writers), rapid response to unknown viruses, and collection of descriptive information about the propagation (through statistics)
• the elimination of false "virus alert" e-mail messages (where the sender is valid) without eliminating "virus alerts" to valid senders
• protection against the most generic form of DoS attacks using network traffic analysis
• protection of SMTP servers against DoS attacks (false notifications, rapid virus propagation or direct attack)
• strengthening protocols to be robust against DoS attacks.

Researchers involved in this project: Boldizsár Bencsáth, Gábor Szabó (student), Géza Szabó (student), and István Vajda

Publications: BV04cts, BV04softcom, B04niif, B04hisec

Publications in 2004

Our teaching activities are mainly related to the base course called Information Security and to the Special on Security of Information and Communication Systems. In 2004, we worked out 1 course (Foundations of Secure Electronic Commerce) and three laboratory exercises (Smart Cards I, Smart Cards II, and PKI and SSL). This completes our contribution (2 courses and 5 laboratory exercises) to the special.

Courses given in 2004

• Information Security (BMEVIHI4363) (fall 2004) (~350 students)
• Network Security Protocols (BMEVIHI4372) (fall 2004) (36 students)
• Secure Electronic Commerce (BMEVIHI5316) (fall 2004) (36 students)
• Cryptography (BMEVIHI9366) (spring 2004)

Boldizsár Bencsáth and István Zsolt Berta provided help in the correction of the tests and exams during the whole year.

Laboratory exercises in 2004

• Network protocol analysis by sniffing (part of BMEVIHI4401)
• Access control in operating systems (part of BMEVIHI4401)
• Smart cards I (ISO 7816 file system and commands) (part of BMEVIHI5317)
• Smart cards II (Java card programming) (part of BMEVIHI5317)
• PKI and SSL (part of BMEVIHI5317)

The exercises were developed by István Zsolt Berta and Attila Bognár with the help of Boldizsár Bencsáth. The exercise sessions were supervised by Boldizsár Bencsáth, István Zsolt Berta, and László Bokor.

Student semester projects in 2004

Projects supervised by Levente Buttyán:

• Analysis of security protocols with the Spi calculus (Gergely Ács and Máté Soós, spring 2004)
• Security of ant based routing in ad hoc networks (Adrián Gulyás, spring 2004)
• Analysis of security protocols with strand spaces (Péter Stoll, spring and fall 2004)
• Axalto Java card programming (Tamás Veiland, spring and fall 2004)
• Wormhole detection in sensor networks (László Dóra, spring and fall 2004)
• Spontaneous cooperation in sensor networks (Tamás Holczer and Péter Schaffer, spring and fall 2004)
• Provable security for ad hoc routing protocols (Gergely Ács, fall 2004)
• Smart card based electronic purse (Dávid Halmos and Tamás Kapócs, fall 2004)
• Side channel attacks against smart cards (Gábor Bárány, fall 2004)

Projects supervised by Boldizsár Bencsáth:

• How to use LDAP in the HUNEID project (Bence Sztanyik, fall 2004)
• SSH user authentication with the HUNEID card (Zoltán Firnigl, fall 2004)
• Application of the HUNEID card in electronic voting (Endre Jenei, fall 2004)
• Application of the HUNEID card for secure e-mail messaging (Attila Pogátsa, fall 2004)
• Integration of the HUNEID card in Mozilla (Dániel Porkoláb, fall 2004)
• SMTPSEC: Securing SMTP (Gábor Szabó, fall 2004)
• VIRUSFALGS: Collaborative components for virus protection (Géza Szabó, fall 2004)

Diploma projects in 2004

• Design criteria of secure computer networks (István Szabó, spring 2004, supervised by Levente Buttyán)
  
  

In 2004, we significantly increased the number of our industrial connections via the establishment of long-term relationships with major smart card manufacturers, participation in an R&D; project, and consulting.

• We have established connections with Axalto, Oberthur Card Systems, and Siemens. Each of these companies donated smart cards and development environment to us, which we have been using in our research, development, and teaching (see our laboratory exercises).
  
  
• We participated in a project funded by the Ministry of Informatics and Communication as a subcontractor of IBM Hungary and E-Group Hungary. The project was called "Detailed requirement specification for the usage of electronic signatures and smart cards in order to ensure IT security of public administration". Our task was the development of the specifications for the Hungarian electronic ID (HUNEID) card and its prototype implemetation. The specifications are available on-line at http://www.itktb.hu/engine.aspx?page=ias.
  
  
• We were contracted by a large Hungarian public transport company to carry out an in-depth analysis and comparison of existing automated fare collection (AFC) systems with respect to their IT security aspects.

Attila Bognár left the lab in the summer of 2004. István Zsolt Berta left the lab in December 2004.