On Redis & AES Encryption in the 9447's CTF

During this last weekend, the 9447 CTF took place. One of the misc problems was called NoSQL and had the following description, together with an attachment with three files:

Hey, I don't understand how SQL works, so I made my own NoSQL startup. And OpenSSL is bloody crap.

ip ...

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Quick and Dirty intro to OpenPGP & GPG

Pretty Good Privacy (PGP) is a model that provides cryptographic privacy and authentication for data communication. It was created by Phil Zimmermann in 1991. Today, PGP is a company that sells a proprietary encryption program, OpenPGP is the open protocol that defines how PGP encryption works, and GnuGP is the ...

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The Peace Pipe at Hack.lu's Final CTF 2014

Last week was the Hack.lu Final CTF. In this post, I discuss one of my favorite crypto problems in that CTF: the "Peace Pipe".

Understanding the Problem

The problem starts with this weird story:

After a long day, you sit around a campfire in the wild wild web with ...
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On Paillier Ciphersystem, Binary Search and the ASIS CTF 2014

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The ASIS CTF happened last weekend. Although I ended up not playing all I wanted, I did spend some time working on a crypto challenge that was worth a lot of points in the game. The challenge was about a sort of a not well-known system, the Paillier cryptosystem.


The ...

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Cryptography War: Beating Krypton

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Continuing to talk about the Wargames, today I'll briefly go through Krypton, the cryptography episode.

The problems are very straightforward and very similar to those from the last CSAW CTF (see my post here).

Disclaimer: if you haven't played WarGames, but you are planning to, PLEASE DON'T ...

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CSAW CTF 2014 - Cryptography 200 - Psifer School

This is the first crypto-problem, and it was supposed to be the easiest one. For this reason, I was expecting simple cryptographic algorithms, which turned out to be true.

The problem starts with the following text:

There's no heartbleed here. Why don't we use these ciphers?

nc 54 ...

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