Hey! I'm David, a security engineer at the Blockchain team of Facebook, previously a security consultant for the Cryptography Services of NCC Group. I'm also the author of the Real World Cryptography book. This is my blog about cryptography and security and other related topics that I find interesting.
I just discovered Cryptool. I can't believed I didn't know about that earlier.
The CrypTool Portal raises awareness and interest in encryption techniques for everyone.
All learning programs in the CrypTool project are open source and available for free. The CrypTool project develops the world most-widespread free e-learning programs in the area of cryptography and cryptoanalysis.
On their main page (cryptool portal) you have links to: Cryptool 1, Cryptool 2, JCryptool, Cryptool Online and Mystery Twister C3. Each project is a huge amount of information that was gathered by a group of volunteer (so yeah, for free). There are tons of tutorials and ways to play with ciphers to understand them. There is even a coppersmith and boneh-durfee explanation/implementation of the attacks I implemented these last months... This is huge. I feel like I'm just discovering the tip of the iceberg and it's all really confusing so here's a recap of what is everything, for me and for you :)
CrypTool 1 (CT1) was the first version of CrypTool. It was released in 1998 and allows to experiment with different cryptographic algorithms. CT1 runs under Windows. CT1 has two successors: CT2 and JCT.
It doesn't seem like it's useful to dig into this one since CT2 and JCT are supposed to be the updated versions. I've still installed it and it looks really old! But it's super complete and super fast so... still super useful.
CrypTool 2 (CT2) supports visual programming and execution of cascades of cryptographic procedures. CT2 also runs under Windows.
I skimmed through it seeing no resemblance to CT1. I have to spend more time with it but CT1 seemed way more educational and complete...
JCrypTool (JCT) is platform-independent and runs under Linux, Mac and Windows.
Haven't tried it yet but it looks like a multiplatform CT2
CrypTool-Online (CTO) was released in spring 2009. This tool allows to try out different algorithms in a browser / smartphone.
I'm gonna be honest here, not really nice compared to CT1 and CT2. Pretty limited.
Mystery Twister C3
You like riddles? You always loved to solve the crosswords in your newspaper? Or maybe you are just curious and want to find out about some of the ways to hide a secret (and possibily even to uncover it)? This is your place! Here at MysteryTwister C3 you can solve crypto challenges, starting from the simple Caesar cipher all the way to modern AES we have challenges for everyone.
The first riddle is just a sequence a number where you have to guess the last entry. Typical IQ test but it has been solved by 2138 people.
The 29th riddle is Hadstad broadcast attack and had only been solved by 102 people.
There are raffles every month so it might be a nice playground :) play here
I wanted to record myself so I could have put that on youtube along with the slides but... I completely forgot once I got on stage. But this is OK as I got corrected on some points, it will make the new recording better :) I will try to make it as soon as possible and upload it on youtube.
I've watched The Imitation Game recently, a movie about Turing, and I was really disappointed at how they don't explain anything at all. I was also disappointed at how much time they spend drinking or doing something else than doing real work, or how they ended the movie before a potentially interesting second part of Turing's life (Imagine if they showed the persecution, it would have been kind of a Life is beautiful. So anyway, I ran into this explanation of Enigma:
It's my first survey ever and I had much fun writing it! I don't really know if I can call it a survey, it reads like a vulgarization/explanation of the papers from Coppersmith, Howgrave-Graham, Boneh and Durfee, Herrmann and May. There is a short table of the running times at the end of each sections. There is also the code of the implementations I coded at the end of the survey.
If you spot a typo or something weird, wrong, or badly explained. Please tell me!