204 research outputs found

    Exploitation of Unintentional Information Leakage from Integrated Circuits

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    Unintentional electromagnetic emissions are used to recognize or verify the identity of a unique integrated circuit (IC) based on fabrication process-induced variations in a manner analogous to biometric human identification. The effectiveness of the technique is demonstrated through an extensive empirical study, with results presented indicating correct device identification success rates of greater than 99:5%, and average verification equal error rates (EERs) of less than 0:05% for 40 near-identical devices. The proposed approach is suitable for security applications involving commodity commercial ICs, with substantial cost and scalability advantages over existing approaches. A systematic leakage mapping methodology is also proposed to comprehensively assess the information leakage of arbitrary block cipher implementations, and to quantitatively bound an arbitrary implementation\u27s resistance to the general class of differential side channel analysis techniques. The framework is demonstrated using the well-known Hamming Weight and Hamming Distance leakage models, and approach\u27s effectiveness is demonstrated through the empirical assessment of two typical unprotected implementations of the Advanced Encryption Standard. The assessment results are empirically validated against correlation-based differential power and electromagnetic analysis attacks

    ASSESSING AND IMPROVING THE RELIABILITY AND SECURITY OF CIRCUITS AFFECTED BY NATURAL AND INTENTIONAL FAULTS

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    The reliability and security vulnerability of modern electronic systems have emerged as concerns due to the increasing natural and intentional interferences. Radiation of high-energy charged particles generated from space environment or packaging materials on the substrate of integrated circuits results in natural faults. As the technology scales down, factors such as critical charge, voltage supply, and frequency change tremendously that increase the sensitivity of integrated circuits to natural faults even for systems operating at sea level. An attacker is able to simulate the impact of natural faults and compromise the circuit or cause denial of service. Therefore, instead of utilizing different approaches to counteract the effect of natural and intentional faults, a unified countermeasure is introduced. The unified countermeasure thwarts the impact of both reliability and security threats without paying the price of more area overhead, power consumption, and required time. This thesis first proposes a systematic analysis method to assess the probability of natural faults propagating the circuit and eventually being latched. The second part of this work focuses on the methods to thwart the impact of intentional faults in cryptosystems. We exploit a power-based side-channel analysis method to analyze the effect of the existing fault detection methods for natural faults on fault attack. Countermeasures for different security threats on cryptosystems are investigated separately. Furthermore, a new micro-architecture is proposed to thwart the combination of fault attacks and side-channel attacks, reducing the fault bypass rate and slowing down the key retrieval speed. The third contribution of this thesis is a unified countermeasure to thwart the impact of both natural faults and attacks. The unified countermeasure utilizes dynamically alternated multiple generator polynomials for the cyclic redundancy check (CRC) codec to resist the reverse engineering attack

    A Novel Protein Kinase-Like Domain in a Selenoprotein, Widespread in the Tree of Life

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    Selenoproteins serve important functions in many organisms, usually providing essential oxidoreductase enzymatic activity, often for defense against toxic xenobiotic substances. Most eukaryotic genomes possess a small number of these proteins, usually not more than 20. Selenoproteins belong to various structural classes, often related to oxidoreductase function, yet a few of them are completely uncharacterised

    Techniques for Improving Security and Trustworthiness of Integrated Circuits

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    The integrated circuit (IC) development process is becoming increasingly vulnerable to malicious activities because untrusted parties could be involved in this IC development flow. There are four typical problems that impact the security and trustworthiness of ICs used in military, financial, transportation, or other critical systems: (i) Malicious inclusions and alterations, known as hardware Trojans, can be inserted into a design by modifying the design during GDSII development and fabrication. Hardware Trojans in ICs may cause malfunctions, lower the reliability of ICs, leak confidential information to adversaries or even destroy the system under specifically designed conditions. (ii) The number of circuit-related counterfeiting incidents reported by component manufacturers has increased significantly over the past few years with recycled ICs contributing the largest percentage of the total reported counterfeiting incidents. Since these recycled ICs have been used in the field before, the performance and reliability of such ICs has been degraded by aging effects and harsh recycling process. (iii) Reverse engineering (RE) is process of extracting a circuit’s gate-level netlist, and/or inferring its functionality. The RE causes threats to the design because attackers can steal and pirate a design (IP piracy), identify the device technology, or facilitate other hardware attacks. (iv) Traditional tools for uniquely identifying devices are vulnerable to non-invasive or invasive physical attacks. Securing the ID/key is of utmost importance since leakage of even a single device ID/key could be exploited by an adversary to hack other devices or produce pirated devices. In this work, we have developed a series of design and test methodologies to deal with these four challenging issues and thus enhance the security, trustworthiness and reliability of ICs. The techniques proposed in this thesis include: a path delay fingerprinting technique for detection of hardware Trojans, recycled ICs, and other types counterfeit ICs including remarked, overproduced, and cloned ICs with their unique identifiers; a Built-In Self-Authentication (BISA) technique to prevent hardware Trojan insertions by untrusted fabrication facilities; an efficient and secure split manufacturing via Obfuscated Built-In Self-Authentication (OBISA) technique to prevent reverse engineering by untrusted fabrication facilities; and a novel bit selection approach for obtaining the most reliable bits for SRAM-based physical unclonable function (PUF) across environmental conditions and silicon aging effects

    Genoomi struktuursed varieeruvused platsenta ja raseduse mÔjutajatena

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    VĂ€itekirja elektrooniline versioon ei sisalda publikatsiooneEma ja loote vaheline suhtlus loob aluse raseduse edukaks kulgemiseks. Rasedus on naise jaoks fĂŒsioloogiline vĂ€ljakutse, mida kinnitab nii varaste (korduv raseduse katkemine, KRK) kui hiliste (preeklampsia, gestatsioonidiabeet, raseduskestuse kohta suur/vĂ€ike sĂŒnnikaal) rasedustĂŒsistuste rohkus. Rasedusaegseid komplikatsioone on sageli seostatud puuduliku platsenta invasiooni ning funktsiooniga, seetĂ”ttu on ÀÀrmiselt oluline tĂ€ielik arusaam platsenta bioloogiast. Platsenta geenide avaldumise tase ja dĂŒnaamika reguleerib platsenta funktsiooni ja seelĂ€bi raseduse kulgemist. Inimese platsenta RNA molekulide profiili moduleerib geneetiline varieeruvus, millest kĂ”ige enam on uuritud ĂŒhenukleotiidseid muutusi. KĂ€esolevas doktoritöös uuriti esmakordselt DNA koopiaarvu muutuste (copy number variation, CNV) mĂ”ju teadmata pĂ”hjusega KRK (=>3 jĂ€rjestikust raseduse katkemist) tekkes. CNV-d pĂ”hjustavad nĂ€htust, kus teatud genoomi osad on kustutatud ja teistest on tehtud lisakoopiaid. CNV-sid on seostatud mitmete erinevate haigustega, kuid vĂ€he on uuringuid rasedustĂŒsistuste vallas. Kogu genoomi CNV piirkondade uuring Eesti ja Taani valimites tuvastas lisakoopia ehk duplikatsiooni 5. kromosoomil, mis suurendab KRK riski naistel ligi viis korda. Antud duplikatsioon hĂ”lmab kahte platsentas kĂ”rgelt avaldunud geeni (PDZD2 ja GOLPH3), mida pole varasemalt rasedusega seostatud. Lisauuringus leiti, et KRK vanemate genoomides leidub enam pikki kromosoomide otste ja keskmete lĂ€heduses asuvaid muutusi, mis vĂ”ivad soosida vigu kromosoomide normaalsel jagunemisel. Lisaks vĂ”rreldi kogu genoomi CNV-de profiili vanemate verest ja platsentast eraldatud DNA-s nii normaalse raseduse erinevatel trimestritel kui rasedustĂŒsistuste korral. Tulemused nĂ€itavad, et raseduse edukaks kulgemiseks ajab platsenta oma rakkude genoomi sassi justkui vĂ€hkkasvaja. SeetĂ”ttu esineb platsenta genoomis suurel hulgal muutusi, eelkĂ”ige duplikatsioone: ligi kuus korda enam kui vanematel genoomis. Kui aga ĂŒmberkorraldusi on liiga vĂ€he, vĂ”ivad tekkida mitmed rasedusaegsed komplikatsioonid. Duplikatsioonid hĂ”lmasid geene, mis on seotud embrĂŒonaalse arenguga ja platsenta rakkude invasiooni toetava protsessiga. See viitab sellele, et platsenta genoomis toimunud muutused soodustavad organi tööd ja raseduse edukat kulgemist.The establishment and maintenance of pregnancy relies on the well-coordinated crosstalk between the mother and the embryo. Pregnancy is an enormous physiological challenge a woman can experience and can cause early (recurrent pregnancy loss, RPL) as well as late (preeclampsia, gestational diabetes mellitus and fetal growth abnormalities) gestational complications. As these complications are often associated with poor trophoblast invasion and placental function, there is an urgent need for complete understanding of placental biology. Placental gene expression levels and dynamics regulate the function of placenta and therefore pregnancy maintenance. Transcriptome of the human placenta is modulated by genetic variation of which single nucleotide variants have been investigated the most. The experimental part of the thesis explored the role of DNA copy number variation (CNV) in idiopathic RPL (=>3 consecutive pregnancy losses). CNVs represent a phenomenon where parts of the genome are missing or duplicated. CNVs have been implicated in various human diseases; however, studies are lacking in reproductive disorders. Genome-wide CNV profiling of parental genomes of Estonian and Danish couples with recurrent pregnancy loss discovered a duplication on chromosome 5 increasing maternal risk of RPL up to 5 times. The duplication encompasses two genes (PDZD2 and GOLPH3) with enhanced expression in placenta and associated with pregnancy maintenance for the first time. Further research detected overrepresentation of large pericentromeric and subtelomeric CNVs in RPL parental genomes that may promote errors in normal chromosome segregation. Additionally, a comparison of genome-wide CNV profiles of parental and placental genomes of three trimesters of normal gestations as well as pregnancy complications was conducted. Similarly to cancer genomes, an extensive load of CNVs was detected as a hallmark of normal placental development. The load was mostly caused by the number of duplications, which were enriched in genes relevant to embryonic development. Early as well as late pregnancy complications showed reduced capacity to promote somatic genomic rearrangements in the placenta. The results indicate that the extensive amount of changes in the placental genome contributes to placental function and successful maintenance of pregnancy
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