• 제목/요약/키워드: Physical Security Card

검색결과 23건 처리시간 0.02초

차분 전력 분석 공격을 위한 향상되고 실제적인 신호 정렬 방법 (Enhanced and Practical Alignment Method for Differential Power Analysis)

  • 박제훈;문상재;하재철;이훈재
    • 정보보호학회논문지
    • /
    • 제18권5호
    • /
    • pp.93-101
    • /
    • 2008
  • 스마트카드, USB token과 같은 저 전력 정보보호장치의 가장 큰 위협요소인 부채널 공격은 장치 내부에 구현된 암호 알고리즘의 이론적인 안전도와는 무관하게 적용될 수 있다. 특히, 부채널 공격들 중에서 차분 전력분석 공격은 적용이 쉽고 근본적인 방어가 어려워서 매우 위협적인 공격이지만 공격을 적용하기 위해서는 측정된 모든 신호가 시간축 상에서 매우 잘 정렬된 신호라는 전제조건이 필요하기 때문에, 트리거 지터링, 잡음, 차분 전력 분석 공격 방어책 등 여러 요인들에 의해 시간축 상에 정렬되지 않은 측정된 신호를 정렬하기 위한 여러 가지 방법들이 제안되어 왔다. 기존의 신호 정렬 방법들은 측정된 신호의 시간축 상의 위치만을 정렬하는 방법들이어서, 랜덤 클럭을 이용하여 알고리즘의 수행 시간(시간축 상의 신호 크기)을 변화시키는 차분 전력 분석 대응 방법에는 적용이 되지 않는다. 본 논문에서는 측정된 소비 전력 신호를 보간(interpolation)과 추출(decimation) 과정을 통해서 시간축 상에서 위치뿐만 아니라 크기도 동시에 정렬시키는 향상된 신호 정렬 방법을 제안하였다. 또한 랜덤 클럭 방식의 차분 전력 분석 공격 방어대책이 구현된 스마트카드 칩에 개선된 신호 정렬 방법을 적용하여 차분 전력 분석 공격이 효과적으로 적용됨을 실험적으로 확인하였다.

Relationship Between Household Food Insecurity and Growth Disorders in Children Aged 3 to 6 in Qazvin City, Iran

  • Gholampour, Tooba;Noroozi, Mostafa;Zavoshy, Rosa;Mohammadpoorasl, Asghar;Ezzeddin, Neda
    • Pediatric Gastroenterology, Hepatology & Nutrition
    • /
    • 제23권5호
    • /
    • pp.447-456
    • /
    • 2020
  • Purpose: Food insecurity, which is the inability to obtain food or inadequate food consumption in terms of quality and quantity, has physical and psychological consequences on children's health. This study aimed to investigate the relationship between children's growth disorders and food insecurity in Qazvin city, Iran. Methods: A case-control study was conducted on 177 cases and 355 controls of children aged 3 to 6 years, who were referred to health centers in Qazvin city. The case group consisted of children with growth disorders. Data were obtained with the 18-item US Department of Agriculture questionnaire, a household socioeconomic questionnaire, a and growth monitoring card. The data were analyzed with using IBM SPSS Version 22.0, by independent sample t-test, chi-square test, and logistic regression. Results: A significant relationship was found between children's growth disorders and household food insecurity with (p<0.05, odds ratio [OR]=17.0, confidence interval [CI]=5.9, 48.8) and without hunger (p<0.05, OR=2.69, CI=1.4, 4.9). There were also significant relationships between children's growth disorders and socioeconomic status (p<0.05, OR=3.4, CI=1.4, 8.5), the duration of breastfeeding (p<0.05, OR=0.94, CI=0.9, 0.98), and children's ages (p<0.05, OR=0.94, CI=0.92, 0.96). Sex and birth order, and the age of the parents was not found to be significantly related with growth disorders. Conclusion: Lower socioeconomic status and household food insecurity were the important predictors of children's growth disorders. Policymakers should focus more on promoting steady employment and income among family members. Nutritional education for mothers is also recommended, in order to better meet the nutritional needs of the children.

Wearable Computers

  • Cho, Gil-Soo;Barfield, Woodrow;Baird, Kevin
    • 섬유기술과 산업
    • /
    • 제2권4호
    • /
    • pp.490-508
    • /
    • 1998
  • One of the latest fields of research in the area of output devices is tactual display devices [13,31]. These tactual or haptic devices allow the user to receive haptic feedback output from a variety of sources. This allows the user to actually feel virtual objects and manipulate them by touch. This is an emerging technology and will be instrumental in enhancing the realism of wearable augmented environments for certain applications. Tactual displays have previously been used for scientific visualization in virtual environments by chemists and engineers to improve perception and understanding of force fields and of world models populated with the impenetrable. In addition to tactual displays, the use of wearable audio displays that allow sound to be spatialized are being developed. With wearable computers, designers will soon be able to pair spatialized sound to virtual representations of objects when appropriate to make the wearable computer experience even more realistic to the user. Furthermore, as the number and complexity of wearable computing applications continues to grow, there will be increasing needs for systems that are faster, lighter, and have higher resolution displays. Better networking technology will also need to be developed to allow all users of wearable computers to have high bandwidth connections for real time information gathering and collaboration. In addition to the technology advances that make users need to wear computers in everyday life, there is also the desire to have users want to wear their computers. In order to do this, wearable computing needs to be unobtrusive and socially acceptable. By making wearables smaller and lighter, or actually embedding them in clothing, users can conceal them easily and wear them comfortably. The military is currently working on the development of the Personal Information Carrier (PIC) or digital dog tag. The PIC is a small electronic storage device containing medical information about the wearer. While old military dog tags contained only 5 lines of information, the digital tags may contain volumes of multi-media information including medical history, X-rays, and cardiograms. Using hand held devices in the field, medics would be able to call this information up in real time for better treatment. A fully functional transmittable device is still years off, but this technology once developed in the military, could be adapted tp civilian users and provide ant information, medical or otherwise, in a portable, not obstructive, and fashionable way. Another future device that could increase safety and well being of its users is the nose on-a-chip developed by the Oak Ridge National Lab in Tennessee. This tiny digital silicon chip about the size of a dime, is capable of 'smelling' natural gas leaks in stoves, heaters, and other appliances. It can also detect dangerous levels of carbon monoxide. This device can also be configured to notify the fire department when a leak is detected. This nose chip should be commercially available within 2 years, and is inexpensive, requires low power, and is very sensitive. Along with gas detection capabilities, this device may someday also be configured to detect smoke and other harmful gases. By embedding this chip into workers uniforms, name tags, etc., this could be a lifesaving computational accessory. In addition to the future safety technology soon to be available as accessories are devices that are for entertainment and security. The LCI computer group is developing a Smartpen, that electronically verifies a user's signature. With the increase in credit card use and the rise in forgeries, is the need for commercial industries to constantly verify signatures. This Smartpen writes like a normal pen but uses sensors to detect the motion of the pen as the user signs their name to authenticate the signature. This computational accessory should be available in 1999, and would bring increased peace of mind to consumers and vendors alike. In the entertainment domain, Panasonic is creating the first portable hand-held DVD player. This device weight less than 3 pounds and has a screen about 6' across. The color LCD has the same 16:9 aspect ratio of a cinema screen and supports a high resolution of 280,000 pixels and stereo sound. The player can play standard DVD movies and has a hour battery life for mobile use. To summarize, in this paper we presented concepts related to the design and use of wearable computers with extensions to smart spaces. For some time, researchers in telerobotics have used computer graphics to enhance remote scenes. Recent advances in augmented reality displays make it possible to enhance the user's local environment with 'information'. As shown in this paper, there are many application areas for this technology such as medicine, manufacturing, training, and recreation. Wearable computers allow a much closer association of information with the user. By embedding sensors in the wearable to allow it to see what the user sees, hear what the user hears, sense the user's physical state, and analyze what the user is typing, an intelligent agent may be able to analyze what the user is doing and try to predict the resources he will need next or in the near future. Using this information, the agent may download files, reserve communications bandwidth, post reminders, or automatically send updates to colleagues to help facilitate the user's daily interactions. This intelligent wearable computer would be able to act as a personal assistant, who is always around, knows the user's personal preferences and tastes, and tries to streamline interactions with the rest of the world.

  • PDF