39 research outputs found

    SDFA: Statistical-Differential Fault Attack on Linear Structured SBox-Based Ciphers

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    At Asiacrypt 2021, Baksi et al. proposed DEFAULT, the first block cipher which provides differential fault attack (DFA) resistance at the algorithm level, with 64-bit DFA security. Initially, the cipher employed a simple key schedule where a single key was XORed throughout the rounds, and the key schedule was updated by incorporating round-independent keys in a rotating fashion. However, at Eurocrypt 2022, Nageler et al. presented a DFA that compromised the claimed DFA security of DEFAULT, reducing it by up to 20 bits for the simple key schedule and allowing for unique key recovery in the case of rotating keys. In this work, we present an enhanced differential fault attack (DFA) on the DEFAULT cipher, showcasing its effectiveness in uniquely recovering the encryption key. We commence by determining the deterministic computation of differential trails for up to five rounds. Leveraging these computed trails, we apply the DFA to the simple key schedule, injecting faults at different rounds and estimating the minimum number of faults required for successful key retrieval. Our attack achieves key recovery with minimal faults compared to previous approaches. Additionally, we extend the DFA attack to rotating keys, first recovering equivalent keys with fewer faults in the DEFAULT-LAYER, and subsequently applying the DFA separately to the DEFAULT-CORE. Furthermore, we propose a generic DFA approach for round-independent keys in the DEFAULT cipher. Lastly, we introduce a new paradigm of fault attack that combines SFA and DFA for any linear structured SBOX based cipher, enabling more efficient key recovery in the presence of both rotating and round-independent key configurations. We call this technique Statistical-Differential Fault Attack (SDFA). Our results shed light on the vulnerabilities of the DEFAULT cipher and highlight the challenges in achieving robust DFA protection for linear structure SBOX-based ciphers

    Divide and Rule: DiFA - Division Property Based Fault Attacks on PRESENT and GIFT

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    The division property introduced by Todo in Crypto 2015 is one of the most versatile tools in the arsenal of a cryptanalyst which has given new insights into many ciphers primarily from an algebraic perspective. On the other end of the spectrum we have fault attacks which have evolved into the deadliest of all physical attacks on cryptosystems. The current work aims to combine these seemingly distant tools to come up with a new type of fault attack. We show how fault invariants are formed under special input division multi-sets and are independent of the fault injection location. It is further shown that the same division trail can be exploited as a multi-round Zero-Sum distinguisher to reduce the key-space to practical limits. As a proof of concept division trails of PRESENT and GIFT are exploited to mount practical key-recovery attacks based on the random nibble fault model. For GIFT-64, we are able to recover the unique master-key with 30 nibble faults with faults injected at rounds 21 and 19. For PRESENT-80, DiFA reduces the key-space from 2802^{80} to 2162^{16} with 15 faults in round 25 while for PRESENT-128, the unique key is recovered with 30 faults in rounds 25 and 24. This constitutes the best fault attacks on these ciphers in terms of fault injection rounds. We also report an interesting property pertaining to fault induced division trails which shows its inapplicability to attack GIFT-128. Overall, the usage of division trails in fault based cryptanalysis showcases new possibilities and reiterates the applicability of classical cryptanalytic tools in physical attacks

    Cryptic Eimeria genotypes are common across the southern but not northern hemisphere

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    The phylum Apicomplexa includes parasites of medical, zoonotic and veterinary significance. Understanding the global distribution and genetic diversity of these protozoa is of fundamental importance for efficient, robust and long-lasting methods of control. Eimeria spp. cause intestinal coccidiosis in all major livestock animals and are the most important parasites of domestic chickens in terms of both economic impact and animal welfare. Despite having significant negative impacts on the efficiency of food production, many fundamental questions relating to the global distribution and genetic variation of Eimeria spp. remain largely unanswered. Here, we provide the broadest map yet of Eimeria occurrence for domestic chickens, confirming that all the known species (Eimeria acervulina, Eimeria brunetti, Eimeria maxima, Eimeria mitis, Eimeria necatrix, Eimeria praecox, Eimeria tenella) are present in all six continents where chickens are found (including 21 countries). Analysis of 248 internal transcribed spacer sequences derived from 17 countries provided evidence of possible allopatric diversity for species such as E. tenella (FST values ⩽0.34) but not E. acervulina and E. mitis, and highlighted a trend towards widespread genetic variance. We found that three genetic variants described previously only in Australia and southern Africa (operational taxonomic units x, y and z) have a wide distribution across the southern, but not the northern hemisphere. While the drivers for such a polarised distribution of these operational taxonomic unit genotypes remains unclear, the occurrence of genetically variant Eimeria may pose a risk to food security and animal welfare in Europe and North America should these parasites spread to the northern hemisphere

    Vulval Tuberculosis

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    A patient with tuberculous ulceration of the vulva is reported. Tuberculosis of the external genitalia is unusual and primary infections are rare. Venereal transmission of the infection could not be proved in the patient. Healing of the ulcer followed antitubercular chemotherapy. The importance of biopsy in the diagnosis of chronic genital ulcer is emphasized

    Love wave in porous layer under initial stress over heterogeneous elastic half-space under gravity and initial stress

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    En este trabajo se estudió el efecto de las tensiones iniciales y la gravedad sobre la propagación de las ondas de Love, lo anterior en la superficie de una capa porosa sobre un semiespacio heterogéneo. Se consideraron dos tipos de límite en superficies libres: (a) límite rígido y (b) límite libre de tracción. La propagación de las ondas de Love ha sido investigada bajo supuestos medios, tanto en los casos de frontera como en un estudio comparativo de dos casos. En ambos, se obtuvieron las ecuaciones de dispersión y las velocidades de fase. Se presentan los cálculos numéricos de forma gráfica. Este estudio de las ondas de Love en el medio supuesto revela que la presencia de tensión inicial en el medio espacio y la ausencia de tensión inicial en la capa, el desplazamiento de la velocidad de fase en un límite rígido es mayor que el límite libre de tracción. doi: https://doi.org/10.22201/igeof.00167169p.2021.60.3.191

    Fracture penis : A complication of sildenafil citrate!

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    Our experience with 6 consecutive cases of fracture penis, a rare urological injury, in normal male without any erectile dysfunction, who consumed Sildenafil Citrate for prolonged sexual enjoyment out of curiosity. All of them were properly worked up and treated surgi-cally resulting in excellent recovery of function

    Primary adenocarcinoma of renal pelvis & ureter: Report of three cases

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    3 rare cases of primary adenocarcinoma of renal pelvis and ureter are illustrated here

    Retained fragmented double J ureteric stent: A report of four cases with review of the literature

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    Polyurethane double-J ureteral stents are widely used in the field of urology. Postoperatively, patient education about the ureteral stent and making sure it is removed at the prescribed time is an utmost necessity. Forgotten ureteral stent is not only disastrous for the patient but also fraught with serious medico-legal implications for the urologist. Herein, we present four cases of long-term retained part of ureteral stent with its varied presentation and subsequent management
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