I bet you have several cards issued by international payment systems (e.g. Visa or MasterCard) in your wallet. Do you know what algorithms are used in these cards? How secure are your payments? People pay with such cards every day but know very little about them. Numerous myths accompany card payments. But to understand what tricks can be used to steal money from a card, you must first get an idea of the payment mechanisms used in it.

When you attack a web app, you sometimes have to perform a certain sequence of actions multiple times (e.g. brute-force a password or the second authentication factor, repeatedly use the same resource, etc.). There are plenty of tools designed for this purpose. Which one to choose if you need, for instance, to make five requests over HTTP a thousand times in a row, while maintaining the same session? My choice is Burp Suite, and in this article, I will explain why.

Quantum computers have been widely discussed since the 1980s. Even though very few people have dealt with them by now, such devices steadily become a harsh reality threatening traditional cryptography. In response to this threat, computer engineers have developed post-quantum encryption algorithms. In this article, I will show how these algorithms are applied in OpenVPN and will give an overview of the current situation in the world of quantum technologies.

Contactless payment cards are very convenient: you just tap the terminal with your card, and a few seconds later, your phone rings indicating that the transaction is completed. But this convenience has a downside: malefactors can steal money from such cards. This article provides an overview of methods used to hack NFC (near-field communication) payment cards.

Each aspiring pentester or information security enthusiast wants to advance at some point from reading exciting write-ups to practical tasks. How to do this in the best way and what should you pay attention to in the first place? In this article, I will describe my own pentesting journey and share some of my findings.

Once you have got a shell on the target host, the first thing you have to do is make your presence in the system ‘persistent’. In many real-life situations, you have only one RCE attempt and cannot afford losing access due to some unexpected event.

If you had ever administered a server, you definitely know that the password-based authentication must be disabled or restricted: either by a whitelist, or a VPN gateway, or in some other way. We decided to conduct an experiment and check what happens if this simple step isn’t taken.