Tae-kyung Kwon

When a user interacts with a computing system to enter a secret password, shoulder surfing attacks are of great concern. To cope with this problem, previous methods presumed limited cognitive capabilities of a human adversary as a deterrent, but there was a pitfall with the assumption. In this paper, we show that human adversaries, even without a recording device, can be more effective at eavesdropping than expected, in particular by employing cognitive strategies and by training themselves. Our

This paper presents a new password authentication and key agreement protocol called AMP in a provable manner. The intrinsic problem with password authentication is a password, associated with each user, has low entropy so that (1) the password is hard to transmit securely over an insecure channel and (2) the password file is hard to protect. Our solution to this complex problem is the amplified password proof idea along with the amplified password file. A party commits the high entropy informati

A wireless sensor network (WSN) is used for a smart home system's backbone that monitors home environment and controls smart home devices to manage lighting, heating, security and surveillance. However, despite its convenience and potential benefits, there are concerns about various security threats that may infringe on privacy and threaten our home life. For protecting WSNs for smart homes from those threats, authentication and key agreement are basic security requirements. There have been a la

Recently there is a growing interest in adaptive mtitimetia networhng where the bandwidth of an ongoing mdtirnedia cdl is variable k this paper we propose a d admission control framework for adaptive mtitimedia servic~in wire l&s/mobile networks. We introduce the degradation period ratio (DPR) QoS parameter, whia represents the portion of a cdl's fifetime that it is ~ocated bandwidth below a pre defined target b=dwidth to the whole stice time of the cdl. Based on DP& we present how to guarantee

Authenticated broadcast, enabling a base station to send commands and requests to low-powered sensor nodes in an authentic manner, is one of the core challenges for securing wireless sensor networks. μTESLA and its multilevel variants based on delayed exposure of one-way chains are well known valuable broadcast authentication schemes, but concerns still remain for their practical application. To use these schemes on resource-limited sensor nodes, a 64-bit key chain is desirable for efficiency, b

Devising a user authentication scheme based on personal identification numbers (PINs) that is both secure and practically usable is a challenging problem. The greatest difficulty lies with the susceptibility of the PIN entry process to direct observational attacks, such as human shoulder-surfing and camera-based recording. This paper starts with an examination of a previous attempt at solving the PIN entry problem, which was based on an elegant adaptive black-and-white coloring of the 10-digit k

Article Bandwidth adaption algorithms with multi-objectives for adaptive multimedia services in wireless/mobile networks Share on Authors: Taekyoung Kwon Department of Computer Engineering, Seoul National University, Seoul, Korea Department of Computer Engineering, Seoul National University, Seoul, KoreaView Profile , Ilkyu Park Department of Computer Engineering, Seoul National University, Seoul, Korea Department of Computer Engineering, Seoul National University, Seoul, KoreaView Profile , Yan

Recently there is a growing interest in adaptive multimedia networking where the bandwidth of an ongoing multimedia call is variable. In this paper, we propose a measurement-based call admission control (CAC) which guarantees the upper bound of the call degradation probability defined herein. Our CAC measures the state of the cellular system in a distributed manner and reflects the observed history of the system on making call admission decisions. Also, a bandwidth adaptation algorithm to minimi

Limitations to the bandwidth of wireless links has motivated the development of adaptive multimedia services where the bandwidth of a call can be dynamically adjusted. A threshold-type call admission control algorithm is proposed for quality of service provisioning; a nonlinear programming model is formulated for determining the optimal threshold values.