Digital contact-tracing (DCT) applications have been installed on more than 188 M smartphones worldwide as an effective mechanism for monitoring contact with COVID-19 infected individuals. DCT is promising not only for COVID-19, but also for preparing for a possible future large-scale pandemic. The DCT framework is unique in that it combines Bluetooth Low Energy (BLE) communications with cryptography techniques to track exposure on a large scale while protecting user privacy. The objective of this study is to assess the risk of the linking attack to the DCT frameworks; i.e., linking individuals to the identifiers contained in BLE broadcast frames that are supposed to be anonymized. Specifically, we target Google/Apple’s Exposure Notification (GAEN), which is the representative implementation of DCT. Our extensive experiments demonstrate that passively collected rolling proximity identifiers (RPIs) contained in the BLE frames can be linked to face photos which could lead to the exposure of privacy information with high accuracy, including infection status. We also demonstrate that an attacker with a few number of devices can correctly link RPIs and the images of the target person with a success rate of 86% at a rate of 5,000 users per hour. Based on these results, we propose countermeasures to reduce the inherent privacy risk of the GAEN framework.

Zero trust (ZT) is a new concept involving the provisioning of enterprise/organization resources to the subjects without relying on any implicit trust. Unlike the perimeter-based architecture in which any subject behind the wall (i.e., inside the predefined perimeter) is considered trusted, zero trust architecture (ZTA) processes any request and provides a resource to the subject without relying on implicit trust. In this paper, based on NIST Special Publication SP800-207, the concept of ZT and ZTA is introduced. Also, challenges, steps, and things to consider when migrating from the legacy architecture to ZTA are presented and discussed.

Today, smart devices and services have become a part of our daily life. These devices and services offer a richer user experience with a much higher quality of services than before. Many of them utilize sensing functions via cloud architecture to perform remote device controls and monitoring. Generally, the security of the communication between these devices and the service provider (e.g., cloud server) is achieved by using the TLS protocol via PKI standard. In this study, we investigate the risk associating with the use of public certificate authorities (CAs) in a PKI-based IoT system. An experiment is conducted to demonstrate existing vulnerabilities in real IoT devices available in the market. Next, the use of a private CA in the cloud-centric IoT architecture is proposed to achieve better control over the certificate issuing process and the validity period of the certificate. Lastly, the security analysis pointing out the strengths and drawbacks of the proposed method is discussed in detail.

As the number of Internet users increases, their usage also diversifies, and it is important to prevent Identity on the Internet (Digital Identity) from being violated. Unauthorized authentication is one of the methods to infringe Digital Identity. Multi-factor authentication has been proposed as a method for preventing unauthorized authentication. However, the cryptographic authenticator required for multi-factor authentication is expensive both financially and UX-wise for the user. In this paper, we design, implement and evaluate multi-factor authentication using My Number Card provided by public personal identification service and WebUSB, which is being standardized.

The Kalray MPPA-256 processor is based on a recent low-energy manycore architecture. In this article, we investigate its performance in multiprecision arithmetic for number-theoretic applications. We have developed a library for modular arithmetic that takes full advantage of the particularities of this architecture. This is in turn used in an implementation of the ECM, an algorithm for integer factorization using elliptic curves. For parameters corresponding to a cryptanalytic context, our implementation compares well to state-of-the-art implementations on GPU, while using much less energy.

Exchanging traffic information among nearby vehicles is one of the communication scenarios in the field of intelligent transport systems (ITS). An important question in this scenario is “How can traffic information be delivered to only one subset of nearby vehicles in the same road traffic situation?”, for example, to only congested traffic in a certain lane. In this demonstration, we propose a dynamic IPv6 multicast group assignment mechanism using GPS, an accelerometer and a magnetometer embedded in smartphones. Our mechanism enables each vehicle to find the relevant vehicles, and to compose a temporary IPv6 multicast address. Our mechanism can deliver traffic information to a group of vehicles in a particular situation. This demonstration, carried out on virtual traffic congestion, shows an information-sharing scenario using a prototype of the proposed mechanism, implemented as an Android application called TrafficCam. Our application demonstrates the usefulness of the proposed mechanism.

Recently there are many huge earthquakes, Tsunami, pandemic of new type virus and so on. For example, Japan is one of the most earthquake-prone countries in the world. People often fall in various unexpected troubles. So we focus on some functions from the views of “Self-Help”, “Mutual-Help” and “Public-Help” in various emergencies and crisis. In this demonstration we report two communication trials by our ε -ARK device family. One is a broadcast communication to generic people by twitter. Another is a document communication by X4iD.

In a peer-to-peer database management system(P2PDBMS) system, peers exchange data in a pair-wise fashion on-the-fly in response to a query without any centralized control. Generally, peers create a temporary session during data exchange. The data might be trapped and disclosed by the intruders while exchanged over an insecure communication network. As there is no centralized control for data exchange among peers, we cannot assume any central third party security infrastructure (e.g. PKI) to protect confidential data of an eHealth P2PDBMS. So far, there is currently no available/existing security protocol for secured data exchange in eHealth P2PDBMS. In this paper we propose a security protocol for data exchange in eHealth P2PDBMSs based on pairing-based cryptography and data exchange policy. The proposed protocol allows the peers to compute their secret session keys dynamically by computing pairing on elliptic curve based on the policies between them during data exchange. Our proposed protocol is robust against the man-in-the middle attack, the masquerade attack and the replay attack.

Recently there are many huge earthquakes, Tsunami, pandemic of new type flu and so on. For example, Japan is one of the most earthquake-prone countries in the world. People often fall in various unexpected troubles. In this demonstration we introduce two prototypes of small information and communication devices which are called Zark and iARK of our " ε-ARK" family. We have developed these devices as a small information communication device that people can carry easily to get and provide the useful function of many which are necessary for the emergency. Especially we focus on some functions from the views of "Self-Help", "Mutual-Help" and "Public-Help" in various emergencies and crisis.

Distributed hash table (DHT) is a specialized distributed system that aims to lookup hashed identifiers efficiently in order to route messages to and from the corresponding nodes and objects. However DHTs are mechanisms sensitive to churn (the continuous and interleaved process of arrival / departure of nodes). As a result, they often cause loss of stored objects and failures in the lookup, a serious issue for all overlay networks. In this paper, we propose a dynamic replica location method using the session log in DHT. Our method can determine dynamically the effective number of replicas on session running periods among anticipate nodes. We also implemented a prototype based on an existing DHT routing algorithm, and we evaluated the performance of the prototype. Our proposed method was shown to reduce data loss and the cost for locating replication.

Abstract The main characteristic of a mobile ad hoc network (MANET) is its infrastructure‐less, highly dynamic topology, which is subject to malicious traffic analysis. Malicious intermediate nodes in MANETs are a threat concerning security as well as anonymity of exchanged information. In this paper, we propose an anonymous on‐demand routing protocol, called RINOMO, to protect anonymity and achieve security of nodes in MANETs. After successful authentication of the legitimate nodes in the network they can use their pseudo IDs for secure communication. Pseudo IDs of the nodes are generated considering pairing‐based cryptography. Nodes can generate their pseudo IDs independently and dynamically without consulting with system administrator. As a result, RINOMO reduces pseudo IDs maintenance costs. Only trust‐worthy nodes are allowed to take part in routing to discover a route. To ensure trustiness each node has to make authentication to its neighbors through the designed anonymous authentication process. Thus, RINOMO safely communicates between nodes without disclosing node identities. It also provides different desirable anonymous properties such as identity privacy, location privacy, route anonymity, and robustness against several attacks. Mathematical analysis of privacy loss is also evaluated and it shows there is no loss of privacy with respect to time. Thus, RINOMO is an anonymous robust protocol in MANETs. Copyright © 2008 John Wiley & Sons, Ltd.