README.md

DownUnderCTF 2020 - Extra Cool Block Chaining

• Category: crypto
• Solves: 52/1391
• Difficulty: ⭐️⭐️
• Hosting type: tcp
• Tags: Block Cipher, Puzzle

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Everyone knows ECB is broken because it lacks diffusion. That's why I've come up with my own variant that uses IVs and chaining and all that cool stuff! It solves all the problems ECB had... I think

Handout files:

• ./challenge/server.py

Solution

Flag: DUCTF{4dD1nG_r4nd0M_4rR0ws_4ND_x0RS_h3r3_4nD_th3R3_U5u4Lly_H3lps_Bu7_n0T_7H1s_t1m3_i7_s33ms!!}

• Writeup
• Solver

External writeups:

• Author's writeup
• rkm0959's writeup