• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.28 no.5
• /
• pp.1047-1057
• /
• 2018

As the number of services offered on the Internet exponentially increases, password managers are increasing popular applications that store several passwords in an encrypted database (or password vault). Browser-integrated password managers or locally-installed password managers store the password vault on the user's device. Although a web-based password manager stores the password vault on the cloud server, a user can store the master password used to sign in the cloud server on her device. An attacker that steals a user's encrypted vault stored in the victim's device can make an offline attack and, if successful, all the passwords in the vault will be exposed to the attacker. This paper investigates the vulnerability of the password vault stored in the device and develops attack programs to verify the vulnerability of the password vault.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.34 no.1
• /
• pp.61-70
• /
• 2024

As users use various services along with the rapid increase in Internet services, it may be difficult to manage accounts. To solve these difficulties, various password management applications are emerging. From a forensic point of view, password management applications can provide clues to obtain criminal evidence. The purpose of this paper is to acquire the data stored by the user in the password management application. To this end, we propose a better way to decrypt the encrypted data through reverse engineering, evaluate the security of the application to be analyzed, and safely store the data.

• The Journal of Korean Association of Computer Education
• /
• v.13 no.5
• /
• pp.103-110
• /
• 2010

If an exterior computer wants to join the Grid/cloud computing platform for a while, all of the related firewalls' filtering rule should be immediately updated. As the platform of Internet application is gradually evolving into the Grid/Cloud environment, the R&D requirement for the dynamic traversing of the multiple firewalls by a single try is also increasing. In this paper, we introduce the new mechanism for the dynamic traversing of the multiple firewalls using the concept of the one-time master key that can dynamically unlock the tiers of firewalls simultaneously instead of the existed filtering rule based method like a lock management at each firewall. The proposed master keys are like one-time password, consisted of IP addresses, port numbers, and TCP's initial sequence numbers, and generated by end users not administrators. They're exchanged mutually in advance and used to make a hole at local-side firewalls for the other's packet incoming. Therefore, the proposed mechanism can function regardless of the number or type of firewalls.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.28 no.4
• /
• pp.789-801
• /
• 2018

Currently widely used IP cameras provide the ability to control IP cameras remotely via mobile devices. To do so, the IP camera software is installed on the website specified by the camera manufacturer, and authentication is performed through the password between the IP camera and the mobile device. However, many products currently used do not provide a secure channel between the IP camera and the mobile device, so that all IDs and passwords transmitted between the two parties are exposed. To solve these problems, we propose an authentication and key exchange protocol using ID-based signature scheme. The proposed protocol is characterized in that (1) mutual authentication is performed using ID and password built in IP camera together with ID-based signature, (2) ID and password capable of specifying IP camera are not exposed, (3) provide forward-secrecy using Diffie-Hellman key exchange, and (4) provide security against external attacks as well as an honest-but-curious manufacturer with the master secret key of the ID-based signature.