Efficient Methods for Exploiting Faults Induced at AES Middle Rounds

Faults occurred during the operations in a hardware device cause many problems such as performance deterioration, unreliable output, etc. If a fault occurs in a cryptographic hardware device, the effect can be even serious because an adversary may exploit it to find the secret information stored in the device. More precisely, the adversary can find the key of a block cipher using differential information between correct and faulty ciphertexts obtained by inducing faults during the computation of ciphertexts. This kind of attack is called \emph{Differential Fault Analysis} (DFA). Among many ciphers \emph{Advanced Encryption Standard} (AES) has been the main target of DFA due to its popularity. AES is widely used in different platforms and systems including Intel and AMD microprocessors. Normally DFA on AES exploits faults induced at the last few rounds. Hence, a general countermeasure is to recompute the last few rounds of AES and compare it with the original output. As redundancy is a costly countermeasure, one should ascertain exactly which rounds need to be protected. In 2006, Phan and Yen introduced a new type of DFA, so called Square-DFA, that works even when faults are induced into some middle rounds. However, it is impractical as it requires several hundreds of faulty ciphertexts as well as a bit fault model. In this article, we propose new attacks that need only dozens of faulty ciphertexts in a byte fault model. Normally it is believed that randomly corrupting a byte is easier than corrupting a specific bit. In addition, we extend the attacks to the AES-192 and AES-256, which is the first result in the literature

Psychological experiences of Korean missionary “kids” (MKs): A qualitative inquiry

The present study is a qualitative investigation of the psychological experiences of children of Korean missionaries, through the eyes of Korean missionary kids (MKs) and missionary workers. A semi-structured interview was conducted with 11 MKs and MK workers, and data were analysed using the Consensual Qualitative Research method. Several domains emerged: challenges associated with the MK experience, resiliency of MKs, intrapersonal and interpersonal coping skills, mental health concerns, religion and spirituality, a complex cultural identity, preparation for college transition, and hopes for MKs and their missionary parents. Categories corresponding to the domains are highlighted. The present study addresses a need for more attention paid to the non-American MK experience, and it presents some implications for the church and higher educational institutions

RFID distance bounding protocol with mixed challenges to prevent relay attacks

RFID systems suffer from different location-based attacks such as distance fraud, mafia fraud and terrorist fraud attacks. Among them mafia fraud attack is the most serious since this attack can be mounted without the notice of both the reader and the tag. An adversary performs a kind of man-in-the-middle attack between the reader and the tag. It is very difficult to prevent this attack since the adversary does not change any data between the reader and the tag. Recently distance bounding protocols measuring the round-trip time between the reader and the tag have been researched to prevent this attack. All the existing distance bounding protocols based on binary challenges, without final signature, provide an adversary success probability equal to (3/4)^n where n is the number of rounds in the protocol. In this paper, we introduce a new protocol based on binary mixed challenges that converges toward the expected and optimal (1/2)^n bound. We prove its security in case of both noisy and non-noisy channels

Methyl 9-diethyl­amino-2,2-bis­(4-meth­oxy­phen­yl)-2H-benzo[h]chromene-5-carboxyl­ate

In the title compound, C31H29NO5, the methyl carboxyl­ate and dimethyl­amino groups on the naphtho­pyran group are almost coplanar with the naphtho­pyran ring system [r.m.s. deviations = 0.08 (2) and 0.161 (2) Å, respectively]. The dihedral angle between the methyl carboxyl­ate and dimethyl­amino groups is 4.9 (1)°. The pyran ring has an envelope conformation with the quaternary C atom out of plane by 0.4739 (13) Å. The meth­oxy­phenyl substituent forms a dihedral angle of 16.6 (1)° with the plane of the benzene ring, while the other meth­oxy­phenyl group is almost coplanar, making a dihedral angle of 1.4 (1)°

N,N-Diethyl-4-[9-meth­oxy-6-(4-methoxy­phen­yl)-5-methyl-2-phenyl-2H-benzo[h]chromen-2-yl]aniline

In the title compound, C38H37NO3, the pyran ring has an envelope conformation with the quaternary Cq atom as the flap atom. The dihedral angle formed between the meth­oxy­phenyl group and the naphthalene ring system is 67.32 (6)°. The ethyl­amino groups lie to the same side of the plane through the phenyl ring and form dihedral angles of 84.6 (3) and 75.8 (2)° with it

Maternity waiting home as a potential intervention for reducing the maternal mortality ratio in El Salvador: an observational case study

Abstract Background El Salvador is recognized as a country that has effectively reduced its Maternal Mortality Ratio (MMR). While health indicators, such as total fertility rate, adolescent fertility rate, skilled birth attendance, and health expenditures, have improved in El Salvador, this improvement was unremarkable compared to advancements in other developing countries. How El Salvador could achieve an outstanding decrease in MMR despite unexceptional improvements in health and non-health indicators is a question that deserves deep research. We used quantitative methods and an observational case study to show that El Salvador could reduce its MMR more than expected by instituting health policies that not only aimed to reduce the (adolescent) fertility rate, but also provide safe birthing conditions and medical services to pregnant women through maternity waiting homes. Methods We ran pooled ordinary least squares regression and panel regression with fixed effects using MMR as the dependent variable and health and non-health factors as the independent variables. We conducted residual analysis, calculated the predicted value of MMR, and compared it with the observed value in El Salvador. To explain the change in MMR in El Salvador, we carried out an observational case study of maternity waiting homes in that country. Results El Salvador could reduce MMR by improving health factors such as fertility rate skilled birth attendance and non-health factors, such as gross domestic product (GDP) per capita and female empowerment. However, even while considering these factors, the MMR of El Salvador decreased by more than expected. We confirmed this by analyzing the residuals of the regression model. This improvement in MMR, which is larger than expected from the regression results, can be attributed partly to government measures such as maternity waiting homes. Conclusions The reason for the unexplained reduction in El Salvadors MMR seems to be attributed in part to health policies that not only aim to reduce the fertility rate but also to provide safe birthing conditions and medical services to pregnant women through maternity waiting homes

Health-Care Networks and the Impact of Maternal Health Care Projects – the Cases of Peru and Bolivia

This paper shows that the evaluation of health projects can be inaccurate when it only considers the direct health-care services provided by health facilities, and that the effects on the entire healthcare network must be considered. In Peru's case, we found that an important effect of a new health facility is the improved service quality in the neighbouring facilities. In Bolivia's case, we found that an improvement of maternal health care service in one hospital may just reduce the demand for medical services in other primary health facilities without significantly affecting the overall performance of the health-care network

Adrenal Cortical Neoplasm with Uncertain Malignant Potential Arising in the Heterotopic Adrenal Cortex in the Liver of a Patient with Beckwith-Wiedemann Syndrome

Patients with Beckwith-Wiedemann syndrome (BWS) are predisposed to developing embryonal tumors, with hepatoblastoma being the most common type. Our patient showed hemihypertrophy, macroglossia, and paternal uniparental disomy in chromosome 11 and was diagnosed with BWS. When the patient was 9 months old, a 2.5×1.5 cm oval hypoechoic exophytic mass was detected in the inferior tip of his right liver. Preoperative imaging identified it as hepatoblastoma; however, histologic, immunohistochemistry, and electron microscopic findings were compatible with adrenal cortical neoplasm with uncertain malignant potential. The origin of the adrenal tissue seemed to be heterotopic. Here, we describe for the first time an adrenal cortical neoplasm with uncertain malignant potential arising in the heterotopic adrenal cortex located in the liver of a patient with BWS