The State of this Blog

Posted on October 01, 2023 in Uncategorized • Tagged with Update, News • 1 min read

An update regarding the state of this blog

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How to find the ASN for any IP Address?

Posted on July 31, 2022 in Programming • Tagged with autonomous system, ASN, API, Security • 4 min read

In the Internet, each IP Address belongs to an autonomous system (AS). In this blog article, it is demonstrated how any IP address can be mapped to an AS number. The necessary information and sources to map each IP Address to an Autnomous System is provided as well, since they were not easy to find.

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db.js — In-Memory Key-Value Database with Persistent File Storage

Posted on May 29, 2022 in Open Source • Tagged with db.js, in-memory database, key-value storage, JSON file persistance • 5 min read

Instead of using one of the many battle proofed and reliable database solutions out there, I rather created my own solution. In this quick blog post, I am announcing the release of db.js - A in-memory database with persistant file storage.

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How to find out if an IP address belongs to a Hosting / Cloud Provider?

Posted on March 09, 2022 in Security • Tagged with API, Datacenter, Hosting, Cloud-Provider, IP API, Bot-Detection, VPN-Detection, IP-Intelligence, IP-Lookup • 8 min read

It is not entirely trivial to find out if an IP address belongs to a datacenter / cloud provider. In this blog article, I try to find an algorithm that outputs with high confidence if an IPv4 / Ipv6 address belongs to a hosting provider or not.

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Fingerprinting TLS - Core differences between TLS 1.2 and TLS 1.3

Posted on January 18, 2022 in Security • Tagged with TLS Fingerprinting, TLS 1.2, TLS 1.3 • 16 min read

In this blog post, I highlight the core differences between TLS 1.2 and TLS 1.3 and investigate how we can use several properties of the protocol to obtain fingerprinting entropy from TLS clients.

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On High-Precision JavaScript Timers

Posted on December 18, 2021 in Security • Tagged with spectre, meltdown, cache-attacks, high-precision-timing, JavaScript • 10 min read

I in this blog post, I am investigating the current state of high precision JavaScript timers. High precision timing techniques were mostly used to launch CPU-level cache attacks such as Spectre and Meltdown from the browser. I am interested in other use cases though...

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