The objective of this paper is to give a comprehensive introduction to applied cryptography with an engineer or computer scientist in mind. The emphasis is on the knowledge needed to create practical systems which supports integrity, confidentiality, or authenticity. Topics covered includes an introduction to the concepts in cryptography, attacks against cryptographic systems, key use and handling, random bit generation, encryption modes, and message authentication codes. Recommendations on algorithms and further reading is given in the end of the paper. This paper should make the reader able to build, understand and evaluate system descriptions and designs based on the cryptographic components described in the paper.

[서평]「Applied Cryptography」

The spatial features of emitted wireless signals are the basis of location distinction and determination for wireless indoor localization. Available in mainstream wireless signal measurements, the Received Signal Strength Indicator (RSSI) has been adopted in vast indoor localization systems. However, it suffers from dramatic performance degradation in complex situations due to multipath fading and temporal dynamics. Break-through techniques resort to finer-grained wireless channel measurement than RSSI. Different from RSSI, the PHY layer power feature, channel response, is able to discriminate multipath characteristics, and thus holds the potential for the convergence of accurate and pervasive indoor localization. Channel State Information (CSI, reflecting channel response in 802.11 a/g/n) has attracted many research efforts and some pioneer works have demonstrated submeter or even centimeter-level accuracy. In this article, we survey this new trend of channel response in localization. The differences between CSI and RSSI are highlighted with respect to network layering, time resolution, frequency resolution, stability, and accessibility. Furthermore, we investigate a large body of recent works and classify them overall into three categories according to how to use CSI. For each category, we emphasize the basic principles and address future directions of research in this new and largely open area.

From RSSI to CSI: Indoor Localization via Channel Response, A survey on indoor localization using PHY-layer information

This paper presents a state-of-the-art survey of smartphone (SP)-based solutions for fall detection and prevention. Falls are considered as major health hazards for both the elderly and people with neurodegenerative diseases. To mitigate the adverse consequences of falling, a great deal of research has been conducted, mainly focused on two different approaches, namely, fall detection and fall prevention. Required hardware for both fall detection and prevention are also available in SPs. Consequently, researchers' interest in finding SP-based solutions has increased dramatically over recent years. To the best of our knowledge, there has been no published review on SP-based fall detection and prevention. Thus in this paper, we present the taxonomy for SP-based fall detection and prevention solutions and systematic comparisons of existing studies. We have also identified three challenges and three open issues for future research, after reviewing the existing articles. Our time series analysis demonstrates a trend towards the integration of external sensing units with SPs for improvement in usability of the systems.

https://www.mdpi.com/1424-8220/14/4/7181/pdf

Smartphone-based solutions for fall detection and prevention: challenges and open issues

본 논문에서는 Dr Gerald J. Holzmann이 제시하였던 커널 스케줄링 방식을 프로세스 알제브라 ACSR-VP를 이용해서 있음을 보인다. 본 오류는 SPIN을 통하여 역시 확인하였다. 이것을 다시 모델링하여 오류를 수정하였고 ACSR-VP와 SPIN으로 오류가 수정되었음을 확인하였다.

Holzmann의 ˝The Model Checker SPIN˝에 대하여

Video encryption has been heavily researched in the recent years. This survey summarizes the latest research results on video encryption with a special focus on applicability and on the most widely-deployed video format H.264 including its scalable extension SVC. The survey intends to give researchers and practitioners an analytic and critical overview of the state-of-the-art of video encryption narrowed down to its joint application with the H.264 standard suite and associated protocols (packaging/streaming) and processes (transcoding/watermarking).

/pdf/a-survey-of-h-264-avc-svc-encryption-1r171okq0l.pdf

A Survey of H.264 AVC/SVC Encryption

A survey of video encryption algorithms

The popularity of multimedia applications is rapidly growing nowadays. The confidentiality of video communication is of primary concern for their commercial use, e.g. in video on demand services or in multiparty video conferences. Specific video encryption algorithms are strongly required in real-time multimedia communication to fulfill the strict timing requi-rements. In this paper we present a novel video encryption algorithm, called Puzzle, to encrypt video data in software. It is fast enough to meet real-time demands and provides a sufficient security. The algorithm can readily be incorporated into existing multimedia systems.

A novel encryption algorithm for high resolution video

Due to demographic changes in developed industrial countries and a better medical care system, the number of elderly people who still live in their home environment is rapidly growing because there they feel more comfortable and independent as in a clinical environment or in a residential care home. The elderly often live alone and receive only irregular visits. Due to impaired physical skills the probability of falls significantly increases. The detection of falls is a crucial aspect in the care of elderly. Falls are often detected very late with severe consequential damages. There are existing approaches for automatic fall detection. They usually deploy special external devices. Elderly people often do not accept these devices because they expose their frailty. In this paper, we present a location-independent fall detection method implemented as a smartphone application for an inconspicuous use in nearly every situation of the daily life. The difficulty of our approach is in the low resolution range of integrated acceleration sensors and the limited energy supply of the smartphone. As solution, we apply a modular threshold-based algorithm which uses the acceleration sensor with moderate energy consumption. Its fall detection rate is in the average of current relevant research.

Location-independent fall detection with smartphone

SIP (Session Initiation Protocol) is becoming the mostly deployed signaling protocol for VoIP (Voice over IP). Security is of utmost importance for its usage due to the open architecture of the Internet. Recently, Yoon et al. proposed a SIP authentication scheme based on elliptic curve cryptography (ECC) that claimed to provide higher security than other schemes. However, as demonstrated in this paper, it is still vulnerable to off-line dictionary and partition attacks.

/pdf/cryptanalysis-of-a-sip-authentication-scheme-q4dfttpbuq.pdf

Cryptanalysis of a SIP authentication scheme

In addition to preventive mechanisms intrusion detection systems (IDS) are an important instrument to protect computer systems. Most IDSs used today realize the misuse detection approach. These systems analyze monitored events for occurrences of defined patterns (signatures), which indicate security violations. Up to now only little attention has been paid to the analysis efficiency of these systems. In particular for systems that are able to detect complex, multi-step attacks not much work towards performance optimizations has been done. This paper discusses analysis techniques of IDSs used today and introduces a couple of optimizing strategies, which exploit structural properties of signatures to increase the analyze efficiency. A prototypical implementation has been used to evaluate these strategies experimentally and to compare them with currently deployed misuse detection techniques. Measurements showed that significant performance improvements can be gained by using the proposed optimizing strategies. The effects of each optimization strategy on the analysis efficiency are discussed in detail.

/pdf/improving-the-efficiency-of-misuse-detection-2h1x02e538.pdf

Hartmut Koenig

Papers

A survey of video encryption algorithms

A novel encryption algorithm for high resolution video

Location-independent fall detection with smartphone

Cryptanalysis of a SIP authentication scheme

Improving the efficiency of misuse detection