Crypto 9

Crypto 9¶

📚 Category: Crypto
🎯 Points: 300
📝 Description: Use flagCheck to input the flag you get from the challenge to get the actual flag

✍️ Writeup¶

We one file:

chall.txt

Cipher text: XI VQHISTUEQH ULEU ULMT XMCC FI QB IETD UETO UB IYIGVUI EQH ULEU XI ESI ETOMQK E CBU JSBP ECC BJ DBV. WI HB QBU JEVCU EQD PIPFIST JBS CIEWMQK, XI ESI FIUUIS BJJ XMULBVU ULBTI XIEO CMQOT. ULI ACEQQMQK TUEKI MT QBX BWIS. ULI OID JBS BVS JMQEC PIIUMQK MT JEXOIT. SIEHD DBVSTICWIT. ULI UMPI LET GBPI JBS VT UB FI JSIIH.

This is a Monoalphabetic Substitution Cipher

ABCDEFGHIJKLMNOPQRSTUVWXYZ
POLYABCDEFGHIJKMNQRSTUVWXZ

WE UNDERSTAND THAT THIS WILL BE NO EASY TASK TO EXECUTE AND THAT WE ARE ASKING A LOT FROM ALL OF YOU. VE DO NOT FAULT ANY MEMBERS FOR LEAVING, WE ARE BETTER OFF WITHOUT THOSE WEAK LINKS. THE PLANNING STAGE IS NOW OVER. THE KEY FOR OUR FINAL MEETING IS FAWKES. READY YOURSELVES. THE TIME HAS COME FOR US TO BE FREED.

Let's check with flagCheck

hacker@csawctf2011~crypto-300-8:/challenge$ ./flagCheck
Enter the flag: FAWKES
Correct flag!
pwn.college{REDACTED}