• Title/Summary/Keyword: Mobile Key Recovery

Search Result 16, Processing Time 0.021 seconds

Recovery Phrase Management Scheme for Public Blockchain Wallets based on OTP (공용 블록체인 지갑을 위한 OTP 기반 계정 복구 문자열 관리 체계)

  • Song, Seounghan;Kim, Suntae;Shin, Jung-Hoon;Lee, Jeong-Hyu
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.20 no.1
    • /
    • pp.35-44
    • /
    • 2020
  • The growing use of public blockchain-based virtual cryptocurrency calls for secure management of blockchain account information managed through cryptocurrency wallet programs. The previously proposed wallet program has high security in terms of managing an account's private key, but low security in managing an account's recovery phrase. Therefore, in this paper, we propose a safe management system of blockchain account recovery string based on the new user authentication method using the user's mobile device information and OTP technique to overcome the problem of the existing account recovery string management method. It also conducts an analysis of the proposed blockchain account recovery string management system based on the expected behavior scenario.

Continuous Behavior of Using Food Delivery Mobile Applications in Vietnam after Covid-19 Pandemic

  • Ha Thu, LUONG;Nhi Lan, DAO;Trang Thu, NGUYEN;Uyen Thu Thi, LA;Na Thi Le, TRAN;Hoa Thi, DUONG
    • Journal of Distribution Science
    • /
    • v.21 no.3
    • /
    • pp.47-60
    • /
    • 2023
  • Purpose: During and after Covid-19 pandemic, technology has emerged as a key factor in supporting the recovery of the economy and the rise of living standards. This study examines seven factors affecting the intention of food delivery apps usage, which include Performance Expectancy, Effort Expectancy, Social Influence, Hedonic Motivation, Price Value, and Habit, and how much influence they have on the customers' behavioral continuance of food delivery apps after Covid-19 Pandemic. Research methodology: This research is a quantitative descriptive research with 473 qualified respondents from 550 respondents collected. Besides using the UTAUT2 model (Venkatesh et al., 2012), Information Quality was added to give a better explanation for the consumers' intention towards continuance behavior using food delivery apps. The collected data is then processed using SPSS 22.0. Results: Habit factors and Information Quality factors have significant positive effects on promoting food delivery apps usage intention, which in turn influences continuance behavior. In addition, Habit factors and Information Quality factors together have an effect of 48.57% on Behavioral Intention. Conclusion: The result proves that positive habits and food information quality can increase the usage intention towards the behavioral continuance of consumers. Higher usage frequency can be improved by increasing these two factors.

Key Recovery Protocol for Mobile Communication Systems (이동 통신 환경에서의 키 복구 프로토콜)

  • Lee, Byung-Rae;Chang, Kyung-Ah;Kim, Tai-Yun
    • Annual Conference of KIPS
    • /
    • 2000.10a
    • /
    • pp.407-410
    • /
    • 2000
  • 본 연구에서는 UMTS[1]에서의 보안 서비스를 실험하고 검증하기 위한 ASPeCT[2]에서 제시한 AIP[3,4] 프로토콜을 위한 개선된 키 복구 프로토콜을 제안한다. AIP 프로토콜은 사용자와 VASP 간에 이루어지는 인증과 지불 초기화를 위한 프로토콜이며 이를 기반으로 하여 이동 통신 기반의 전자상거래가 실현될 수 있다. 제안된 키 복구 프로토콜은 검증 가능한 비밀 공유 프로토콜[5,6,7]을 기반으로 하여 다수의 키 복구 기관과의 연관을 통하여 개선된 안전성을 제공하고 악의적인 사용자가 잘못된 비밀 정보를 키 복구 기관(KRA)에게 위탁하는 것을 방지한다.

  • PDF

Performance Analysis of Pilot Symbol Assisted Trellis-Coded 8PSK with Timing Recovery Circuits on the Frequency-Nonselective Rayleigh Fading Channel (주파수 비선택적 레일리 페이딩 채널에서의 타이밍 복구회로를 고려한 PSA-TC-8PSK의 성능 분석)

  • 이병로
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.5 no.3
    • /
    • pp.419-425
    • /
    • 2001
  • In land mobile communications, multipath fading is one of the key factors which affect the system performance. Some extensive studies have been carried out to improve the degraded performance under this fading channels. The PSAM channel compensation method using channel fading estimation is widely used and TCM is a combined coding and modulation technique that has been shown to provide significant coding gain without increasing the transmission bandwidth. In this paper, we analyze the performance of PSA-TC-8PSK which combines PSAM and TCM over frequency nonselective fading channels. To estimate channel fading, Wiener filter which minimizes error variance is used as compensation method and we analyze the affects on the system performance of the number of filter taps, period of the pilot symbol frame, and the Doppler frequency. In addition, we consider the symbol timing recovery circuit which can be implemented in the full-digital method and analyze the effects of symbol timing error on the system performance.

  • PDF

Temporary Metadata Journaling Scheme to Improve Performance and Stability of a FAT Compatible File System (FAT 파일 시스템의 호환성을 유지하며 성능과 안정성을 향상시키는 메타데이터 저널링 기법의 설계)

  • Hyun, Choul-Seung;Choi, Jong-Moo;Lee, Dong-Hee;Noh, Sam-H.
    • Journal of KIISE:Computer Systems and Theory
    • /
    • v.36 no.3
    • /
    • pp.191-198
    • /
    • 2009
  • The FAT (File Allocation Table) compatible file system has been widely used in mobile devices and memory cards because of its data exchangeability among numerous platforms recognizing the FAT file system. By the way. modern embedded systems have tough demands for instant power failure recovery and superior performance for multimedia applications. The key issue is how to achieve the goals of superior write performance and instant booting capability while controlling compatibility issues. To achieve the goals while controlling compatibility issues. we devised a temporary meta-data journaling scheme for a FAT compatible file system. Benchmark results of the scheme implemented in a FAT compatible file system shows that it really improves write performance of the FAT file system by converting small random write for meta-data update to a large sequential write in journaling area. Also, it provides natural way to implement the instant booting capability. Nevertheless, the file system compatibility is temporarily compromised by the scheme because it stores updated meta-data in the temporary journaling area rather than to their original locations. However, the compatibility can be fully recovered at any time by journal-flushing that copies meta-data in journaling area to their original locations. Generally, the journal-flushing is done before un-mounting a memory card so that it can be used in other mobile devices which recognized FAT file system but not the temporary meta-data journaling scheme.

Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2016 (설비공학 분야의 최근 연구 동향 : 2016년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.29 no.6
    • /
    • pp.327-340
    • /
    • 2017
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2016. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of flow, heat and mass transfer, the reduction of pollutant exhaust gas, cooling and heating, the renewable energy system and the flow around buildings. CFD schemes were used more for all research areas. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results of the long-term performance variation of the plate-type enthalpy exchange element made of paper, design optimization of an extruded-type cooling structure for reducing the weight of LED street lights, and hot plate welding of thermoplastic elastomer packing. In the area of pool boiling and condensing, the heat transfer characteristics of a finned-tube heat exchanger in a PCM (phase change material) thermal energy storage system, influence of flow boiling heat transfer on fouling phenomenon in nanofluids, and PCM at the simultaneous charging and discharging condition were studied. In the area of industrial heat exchangers, one-dimensional flow network model and porous-media model, and R245fa in a plate-shell heat exchanger were studied. (3) Various studies were published in the categories of refrigeration cycle, alternative refrigeration/energy system, system control. In the refrigeration cycle category, subjects include mobile cold storage heat exchanger, compressor reliability, indirect refrigeration system with $CO_2$ as secondary fluid, heat pump for fuel-cell vehicle, heat recovery from hybrid drier and heat exchangers with two-port and flat tubes. In the alternative refrigeration/energy system category, subjects include membrane module for dehumidification refrigeration, desiccant-assisted low-temperature drying, regenerative evaporative cooler and ejector-assisted multi-stage evaporation. In the system control category, subjects include multi-refrigeration system control, emergency cooling of data center and variable-speed compressor control. (4) In building mechanical system research fields, fifteenth studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, renewable energies, etc. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which could be help for improving the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the analyses of indoor thermal environments controlled by portable cooler, the effects of outdoor wind pressure in airflow at high-rise buildings, window air tightness related to the filling piece shapes, stack effect in core type's office building and the development of a movable drawer-type light shelf with adjustable depth of the reflector. The subjects of building energy were worked on the energy consumption analysis in office building, the prediction of exit air temperature of horizontal geothermal heat exchanger, LS-SVM based modeling of hot water supply load for district heating system, the energy saving effect of ERV system using night purge control method and the effect of strengthened insulation level to the building heating and cooling load.