Networking

Subject: Cyber Security II (KB II), Department of Telecommunications, Faculty of electrical engineering and computer science, VSB-TUO Name: Bc. Kryštof Šara (SAR0130) Date of presentation: May 10, 2024 Task syllabus: design and configuration of test topology using network monitoring tools - Zabbix, Nagios, including their configuration description of the methods used to maintain high availability and their practical example introduction As far as modern computational systems are concerned, it is common to ensure those are operational no matter what happens....

Annotation: Telecommunications laboratory (telco lab) is the next step in the old hardware collection’s further usage and analysis. About 10+ various [mainly U.S.Robotics (USR) branded] voice 56kbit (fax)modems for dial-up Internet connection had been collected. This article gives a Prove of Concept (PoC) to the modem-modem link establishment over the VoIP RTP stream with aim to build a dial-in ISP service. Various VoIP technology’s underlying parameters, and modem configurations had been tuned with batch dial-up connection testing being executed, and then commented....

Subject: Cyber Security I (KB I), Department of Telecommunications, Faculty of electrical engineering and computer science, VSB-TUO. Name: Bc. Kryštof Šara (SAR0130) Date of presentation: December 15, 2023 Task description: Application description, testbed creation, implementation of some of the most well-known scenarios for VPN - 1: 1 and N: 1, connection of PKI with VPN introduction In the modern era of digital nomadism, where one can roam virtually anywhere around the globe, while still having a connection to public Internet, it is crutial to ensure an additional layer of security for businesses as well as for individuals (public WiFi access points)....

Subject: Cyber Security I (KB I), Department of Telecommunications, Faculty of electrical engineering and computer science, VSB-TUO. Name: Bc. Kryštof Šara (SAR0130) Date of presentation: December 15, 2023 introduction In the modern era, it is a standard to ensure HTTP over SSL/TLS layer (HTTPS) on any web page possible. However, the implementation of Public Key Infrastructure (PKI), such as getting the keys and certificates can be a problem, when using internal domain name systems and internal domains, that are not accessible from the Internet....

monkeVPN is a simple wireguard project for intersted one to securely browse the web. In detail, one connects to one given endpoint making all traffic between encrypted. This allows one to securely serf the waves on the Internet even when connected to the public transportation hotspot with tens of people lurking for some bandwidth too. As WiFi signal is broadcasted in all ways around the antennae, it is very simple to capture any unencrypted data floating around....

motivation This story of dish starts in the year 2016. I was developing my first “mature” Information System (based on sakalWeb IS 4). Out of blue I got an idea about how to monitor other services, and how cool it would be to see green a red labels jumping around to signalize service’s last status. The latter version (around 2018) was mostly inspired by Zabbix interface. I just wanted a list of services, their last status, amount of time after last test....

Subject: Multimedia Communication and Content Security (MZKO), Department of Telecommunications, Faculty of electrical engineering and computer science, VSB-TUO. Name: Bc. Kryštof Šara (SAR0130) Task syllabus: master key exchange (symetric cryptography) SRTP-DES exchange, SIP VoIP, SDP session descriptor, RTP stream description (codecs, media type, ports, SRTP master key in bae64) in SIP signalling key distribution problem (MitM-prone) ZRTP and Diffie-Hellmann (DH) alg (MitM-prone and DH implementation in old HW problem) SRTP-DTLS session, WebRTC over DTLS channel, media encryption simulation introduction In the world of a continuous need for communication (preferably in real-time), it is vital for the media stream transportation to be reliable (uninterrupeted), secure (end-to-end encrypted, and fast (UDP/IP, low jitter and RTT)....