# On Paillier Ciphersystem, Binary Search and the ASIS CTF 2014

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 ...

more ...# Cryptography War: Beating Krypton

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 ...

# 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:

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

nc 54 ...