A couple of reader alerts:

In order to (somewhat) simplify the description process and tighten the volume of the article we are going to write, it is essential to make a significant remark and state the primary constraint right away — everything we are going to tell you today on the practical side of the problematics is viable only in terms of TLS 1.3. Meaning that while your ECDSA certificate would still work in TLS 1.2 if you wish it worked, providing backwards compatibility, the description of the actual handshake process, cipher suits and client-server benchmarks covers TLS 1.3 only. Of course, this does not relate to the mathematical description of algorithms behind modern encryption systems.

This article was written by neither a mathematician nor an engineer — although those helped to find a way around scary math and reviewed this article. Many thanks to Qrator Labs employees.

(Elliptic Curve) Diffie-Hellman (Ephemeral)

The Diffie–Hellman legacy in the 21 century

Of course, this has started with neither Diffie nor Hellman. But to provide a correct timeline, we need to point out main dates and events.

There were several major personas in the development of modern cryptography. Most notably, Alan Turing and Claud Shannon both laid an incredible amount of work over the field of theory of computation and information theory as well as general cryptanalysis, and both Diffie and Hellman, are officially credited for coming up with the idea of public-key (or so-called asymmetric) cryptography (although it is known that in the UK there were made serious advances in cryptography that stayed under secrecy for a very long time), making those two gentlemen pioneers.

In what exactly?

For those of you still now subscribed to the Cybersecurity Newsletter - the form is at the top of the page.

Best news, articles and scientific papers published since August 12 till 18 are below.

TL;DR: Client-server architecture of our internal configuration management tool, QControl. 
At its basement, there’s a two-layered transport protocol working with gzip-compressed messages without decompression between endpoints. Distributed routers and endpoints receive the configuration updates, and the protocol itself makes it possible to install intermediary localized relays. It is based on a differential backup (“recent-stable,” explained further) design and employs JMESpath query language and Jinja templating for configuration rendering.

Qrator Labs operates on and maintains a globally distributed mitigation network. Our network is anycast, based on announcing our subnets via BGP. Being a BGP anycast network physically located in several regions across the Earth makes it possible for us to process and filter illegitimate traffic closer to the Internet backbone — Tier-1 operators.

On the other hand, being a geographically distributed network bears its difficulties. Communication between the network points-of-presence (PoP) is essential for a security provider to have a coherent configuration for all network nodes and update it in a timely and cohesive manner. So to provide the best possible service for customers, we had to find a way to synchronize the configuration data between different continents reliably.

In the beginning, there was the Word… which quickly became communication protocol in need of an upgrade.

This post represents a regular Cybersecurity Newsletter issue, available at the dedicated subscribe page.

This time, we are between August 5 and 11 with the best articles, blog posts, and preprints.

This blogpost represents a regular Cybersecurity Newsletter issue, available at the dedicated subscribe page.

This time, we're between July 29 and August 3 with the best articles posted.

TL;DR: starting February 2020, DNS servers that don’t support DNS both over UDP and TCP may stop working.

Bangkok, in general, is a strange place to stay. Of course, it is warm there, rather cheap and some might find the cuisine interesting, along with the fact that about half of the world’s population does not need to apply for a visa in advance to get there. However, you still need to get acquainted with the smells, and the city streets are casting cyberpunk scenes more than anything else.

In particular, a photo to the left has been taken not far from the center of Thailand’ capital city, one street away from the Shangri-La hotel, where the 30th DNS-OARC organization meeting took place on May 12 and 13. It is a non-profit organization dedicated to security, stability, and overall development of the DNS — the Domain Name System.

Slides from the DNS-OARC 30 meeting are recommended for everyone interested in how the DNS works, though perhaps the most interesting is what is absent in those slides. Namely, a 45-minute round table with a discussion around the results of DNS Flag Day 2019, which occurred on February, 1, 2019.

And, the most impressive result of a round table is the decision to repeat DNS Flag Day once again.

As we wrote in the 2018-2019 Interconnected Networks Issues and Availability Report at the beginning of this year, TLS 1.3 arrival is inevitable. Some time ago we successfully deployed the 1.3 version of the Transport Layer Security protocol. After gathering and analyzing the data, we are now ready to highlight the most exciting parts of this transition.

As IETF TLS Working Group Chairs wrote in the article:
“In short, TLS 1.3 is poised to provide a foundation for a more secure and efficient Internet over the next 20 years and beyond.” 

TLS 1.3 has arrived after 10 years of development. Qrator Labs, as well as the IT industry overall, watched the development process closely from the initial draft through each of the 28 versions while a balanced and manageable protocol was maturing that we are ready to support in 2019. The support is already evident among the market, and we want to keep pace in implementing this robust, proven security protocol.

Eric Rescorla, the lone author of TLS 1.3 and the Firefox CTO, told The Register that:
“It's a drop-in replacement for TLS 1.2, uses the same keys and certificates, and clients and servers can automatically negotiate TLS 1.3 when they both support it,” he said. “There's pretty good library support already, and Chrome and Firefox both have TLS 1.3 on by default.”

In general, Qrator Labs filtering service involves two stages: first, we immediately evaluate whether a request is malicious with the help of stateless and stateful checks, and, secondly, we decide whether or not to keep the source blacklisted and for how long. The resulting blacklist could be represented as the list of unique IP-addresses.

That is a quote from one of my favorite bands. Dave Gahan from Depeche Mode is a living proof that you can say the word “wrong” 65 times in 5 minutes and still be a rock star. Let’s see how that’s going to work for me.