Sep
21

hack.lu CTF 2011 Spy Aboard! (300)

Category: crypto We have a spy aboard! For around 5 minutes ago we intercepted an encrypted transmission to an enemy outpost. It seems like we interrupted the mole in the act because we found an open transmission program on our terminals. We are 100% sure that he sent the position of our fleet to the… Continue reading »

Oct
30

Hack.lu 2010 CTF Challenge #7 Writeup

Breiers Deathmatch (150) Schnuce Breier has challenged you to a cryptographer’s deathmatch. Connect to pirates.fluxfingers.net 8007/tcp and get the secret number. $ nc pirates.fluxfingers.net 8007 Hi. This is your friendly ‘Decryption Oracle’ We have implemented a well-known public-key cryptosystem. Guess which ;) Modulo: 5628290459057877291809182450381238927697314822133923421169378 062922140081498734424133112032854812341 Generator: 99 Public Key: 135744434201778324839308712462911647727754874814096844915 5264250239122362719894347099351280643528244 Ciphertext: (44750535504622985677351849167148532593337860047243938284 03819968944371696234280482660523326406427034, 40867215175893797288404… Continue reading »