Kim Jong-gil

In this paper, we present an adaptively secure identity-based broadcast encryption system featuring constant sized ciphertext in the standard model. The size of the public key and the private keys of our system are both linear in the maximum number of receivers. In addition, our system is fully collusion-resistant and has stateless receivers. Compared with the state-of-the-art, our scheme is well optimized for the broadcast encryption. The computational complexity of decryption of our scheme dep

Robot Operating System (ROS) 2 is a ground-up re-design of ROS 1 to support performance critical cyber-physical systems (CPSs) using the Data Distribution Service (DDS) middleware. Accordingly, the security of ROS 2 is highly reliant on the security of its DDS communication protocol. However, finding a balance between the performance and security is non-trivial task. Inappropriate security implementations may cause not only significant loss on performance of the system, but also security failure

The amount of encrypted Internet traffic almost doubles every year thanks to the wide adoption of end-to-end traffic encryption solutions such as IPSec, TLS and SSH. Despite all the benefits of user privacy the end-to-end encryption provides, the encrypted internet traffic blinds intrusion detection system (IDS) and makes detecting malicious traffic hugely difficult. The resulting conflict between the user's privacy and security has demanded solutions for deep packet inspection (DPI) over encryp

Cloud storage services have become ubiquitous. A large number of individuals and organizations are using them to store and share data, taking the benefits of mobility and affordability offered by these services. However, secure management of data in cloud storage services, more specifically supporting multi-party sharing in the context of a collaboration, is a challenging problem. The problem is further exacerbated if the data owner does not have any trust on the cloud storage providers and the

Each layer of nodes and communication networks in edge computing, from cloud to the end device (i.e, often considered as resource-constrained IoT devices), exhibits a different level of trust for each stakeholder - e.g., edge nodes may not be fully trusted by IoT devices and the cloud. Moreover, asymmetric nature of resources between layers makes it hard to establish a balance between security and performance - e.g., lightweight cryptography may degrade security level against untrusted nodes whi

We introduce an efficient Key-Policy Attribute-Based Encryption (KP-ABE) scheme in prime order groups. Our scheme is semi-adaptively secure under the decisional linear assumption and supports a large universe of attributes and multi-use of attributes. Those properties are critical for real applications of KP-ABE schemes since they enable an efficient and flexible access control. Prior to our work, existing KP-ABE schemes with short ciphertexts were in composite order groups or utilized either Du

The forecasting of container volume which is the basis of port logistics facilities expansion has a great influence on development of an port. Based on this importance, various previous studies have presented methodology on container volume forecasting. The results of many previous studies pointed out the limitations of future forecasting based on past container volume and emphasized that more various factors should be considered to compensate this. Taking notice of this point, this study foreca

The authority of the state and the market, the duumvirate of the industrial society, has been challenged in various ways in the current information era advanced by the rapid development of information and communication technology. By comparison, the weight of civil organizations has increased sharply, and netizens equipped with information technology have emerged as a major player in civil society. This article experientially examines the changes in power dynamics of the state, the market, and c

In this paper, we present a new identity-based encryption (IBE) system that is named Backward Compatible Identity-based Encryption (BC-IBE). Our BC-IBE is proposed to solve the problem caused by the out-of-synchronization between users' private keys and ciphertexts. Encryption systems such as revocable IBE or revocable Attribute-based Encryption (ABE) often require updating private keys to revoke users after a certain time period. However, in those schemes, an updated key can be used to decrypt

According to Google's transparency report, 99% of the pages loaded on the Chrome browser are over HTTPS.Encrypting the data traffic becomes almost the default requirement for not only secret data transmission but also users' privacy.However, encrypting data traffic makes us face a new threat.Particularly, conventional middlebox systems such as network intrusion detection systems and other network monitoring systems cannot effectively detect malicious activities over encrypted traffic.Due to this