Marcos Portnoi

Learn More
In order to make recommendations to users about the potential performance of advanced Internet applications - in the scope of network monitoring - it is not sufficient to just analyze the network performance metrics: it should be also considered information concerning the application type, the traffic generated, and the user profile. In the present paper,(More)
This paper presents a new discrete event-based network simulator named TARVOS – Computer Networks Simulator, being designed as part of the first Author's Masters research and will provide support to simulating MPLS architecture, several RSVP-TE protocol functionalities and fast recovery in case of link failure. The tool is used in a case study, where the(More)
Traditional user authentication involves entering a username and password into a system. Strong authentication security demands, among other requirements, long, frequently hard-to-remember passwords. Two-factor authentication aids in the security, even though, as a side effect, might worsen user experience. We depict a mobile sign-on scheme that benefits(More)
This work presents a mobile sign-on scheme, which utilizes Bluetooth Low Energy beacons for location awareness and Attribute-Based Encryption for expressive, broadcast-style key exchange. Bluetooth Low Energy beacons broadcast encrypted messages with encoded access policies. Within range of the beacons, a user with appropriate attributes is able to decrypt(More)
A distributed, hierarchical information service for computer networks might use several service instances, located in different layers. A distributed directory service, for example, might be comprised of upper level listings, and local directories. The upper level listings contain a compact version of the local directories. Clients desiring to access the(More)
We introduce LOCATHE (Location-Enhanced Authenticated Key Exchange), a generic protocol that pools location, user attributes, access policy and desired services into a multi-factor authentication, allowing two peers to establish a secure, encrypted session and perform mutual authentication with pre-shared keys, passwords and other authentication factors.(More)
The Quake-Catcher Network (QCN) project uses the low-cost sensors, i.e., accelerometers attached to volunteers' computers, to detect earthquakes. The master-worker topology currently used in QCN and other similar projects suffers from major weaknesses. The centralized master can fail to collect data if the volunteers' computers cannot connect to the(More)
This paper presents an overview of the use of elliptic curves in cryptography. The security of this cryptosystem is based on the discrete logarithm problem, which appears to be much harder compared to the discrete logarithm problem in other cryptosystems. An overview of common cryptosystems is given, such as Diffie-Hellman and RSA, and an elliptic curve(More)
Index Terms—cyber-physical system; attribute-based encryption; context-awareness; safety; software agent; wireless communication; firearm I. INTRODUCTION Advances of digital technologies, as they are incorporated into devices for people's usage, often result in enhancements including ease of use, safety, precision, optimizations in resource consumption and(More)