Katerina Mitrokotsa
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Prof. Dr.
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Mitrokotsa
First name
Katerina
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katerina.mitrokotsa@unisg.ch
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+41 71 224 7861
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https://twitter.com/mitrokat
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  • Publication
    On selecting the nonce length in distance-bounding protocols.
    (Oxford University Press, 2013-04-04)
    Mitrokotsa, Aikaterini
    ;
    Peris-Lopez, Pedro
    ;
    Dimitrakakis, Christos
    ;
    Vaudenay, Serge
    Distance-bounding protocols form a family of challenge–response authentication protocols that have been introduced to thwart relay attacks. They enable a verifier to authenticate and to establish an upper bound on the physical distance to an untrusted prover. We provide a detailed security analysis of a family of such protocols. More precisely, we show that the secret key shared between the verifier and the prover can be leaked after a number of nonce repetitions. The leakage probability, while exponentially decreasing with the nonce length, is only weakly dependent on the key length. Our main contribution is a high probability bound on the number of sessions required for the attacker to discover the secret, and an experimental analysis of the attack under noisy conditions. Both of these show that the attack's success probability mainly depends on the length of the used nonces rather than the length of the shared secret key. The theoretical bound could be used by practitioners to appropriately select their security parameters. While longer nonces can guard against this type of attack, we provide a possible countermeasure which successfully combats these attacks even when short nonces are used.
    Type: journal article
    Journal: The Computer Journal
    Volume: 56
    Issue: 10
    DOI: 10.1093/comjnl/bxt033
    URI: https://www.alexandria.unisg.ch/handle/20.500.14171/89441
    Scopus© Citations 14
  • Publication
    Evaluation of Classification Algorithms for Intrusion Detection in MANETs.
    (Elsevier, 2012)
    Pastrana, Sergio
    ;
    Mitrokotsa, Aikaterini
    ;
    Orfila, Agustin
    ;
    Peris-Lopez, Pedro
    Mobile Ad hoc Networks (MANETs) are wireless networks without fixed infrastructure based on the cooperation of independent mobile nodes. The proliferation of these networks and their use in critical scenarios (like battlefield communications or vehicular networks) require new security mechanisms and policies to guarantee the integrity, confidentiality and availability of the data transmitted. Intrusion Detection Systems used in wired networks are inappropriate in this kind of networks since different vulnerabilities may appear due to resource constraints of the participating nodes and the nature of the communication. This article presents a comparison of the effectiveness of six different classifiers to detect malicious activities in MANETs. Results show that Genetic Programming and Support Vector Machines may help considerably in detecting malicious activities in MANETs.
    Type: journal article
    Journal: Knowledge-Based Systems
    Volume: 36
    DOI: 10.1016/j.knosys.2012.06.016
    URI: https://www.alexandria.unisg.ch/handle/20.500.14171/92788
  • Publication
    A Comprehensive RFID Solution to Enhance Inpatient Medication Safety.
    (Elsevier, 2011-01)
    Peris-Lopez, Pedro
    ;
    Orfila, Agustin
    ;
    Mitrokotsa, Aikaterini
    ;
    van der Lubbe, Jan C.A.
    Errors involving medication administration can be costly, both in financial and in human terms. Indeed, there is much potential for errors due to the complexity of the medication administration process. Nurses are often singled out as the only responsible of these errors because they are in charge of drug administration. Nevertheless, the interventions of every actor involved in the process and the system design itself contribute to errors (Wakefield et al. (1998) [23]). Proper inpatient medication safety systems can help to reduce such errors in hospitals. In this paper, we review in depth two recent proposals (Chien et al. (2010) [7]; Huang and Ku (2009) [12]) that pursue the aforementioned objective. Unfortunately, they fail in their attempt mainly due to their security faults but interesting ideas can be drawn from both. These security faults refer to impersonation and replay attacks that could produce the generation of a forged proof stating that certain medication was administered to an inpatient when it was not. We propose a leading-edge solution to enhance inpatient medication safety based on RFID technology that overcomes these weaknesses. Our solution, named Inpatient Safety RFID system (IS-RFID), takes into account the Information Technology (IT) infrastructure of a hospital and covers every phase of the drug administration process. From a practical perspective, our system can be easily integrated within hospital IT infrastructures, has a moderate cost, is very ease to use and deals with security aspects as a key point.
    Type: journal article
    Journal: International Journal of Medical Informatics (IJMI)
    Volume: 80
    Issue: 1
    DOI: 10.1016/j.ijmedinf.2010.10.008
    URI: https://www.alexandria.unisg.ch/handle/20.500.14171/94688
    Scopus© Citations 103
  • Publication
    Reid et al.'s Distance Bounding Protocol and Mafia Fraud Attacks over Noisy Channels.
    (IEEE, 2010-02-05)
    Mitrokotsa, Aikaterini
    ;
    Dimitrakakis, Christos
    ;
    Peris-Lopez, Pedro
    ;
    Hernandez-Castro, J.C.
    Distance bounding protocols are an effective countermeasure against relay attacks including distance fraud, mafia fraud and terrorist fraud attacks. Reid et al. proposed the first symmetric key distance bounding protocol against mafia and terrorist fraud attacks. However, claims that this is only achieved with a (7/8) n probability of success for mafia fraud, rather than the theoretical value of (3/4) n (for n rounds) achieved by distance bounding protocols without a final signature. We prove that the mafia fraud attack success using the Reid et al. protocol is bounded by (3/4) n and reduces as noise increases. The proof can be of further interest as it is the first - to the best of our knowledge - detailed analysis of the effects of communication errors on the security of a distance bounding protocol.
    Type: journal article
    Journal: IEEE Communications Letters
    Volume: 14
    Issue: 2
    URL: https://ieeexplore.ieee.org/document/5403607
    DOI: 10.1109/LCOMM.2010.02.091946
    URI: https://www.alexandria.unisg.ch/handle/20.500.14171/96815
    Scopus© Citations 22