attack-defense-platform/services/blinkpdf/README.md

blinkpdf

Author

wondPing

Description

Lately, I have been studying signature algorithms. However, that's not enough, so I tried to make some modifications. Next, I attempted to implement it for signing a PDF document. You need the credentials user:user to Login. attachment: https://drive.google.com/drive/folders/1u05M-eq50ZJjO7Ww4EHWBYeHJH6zyFCC?usp=sharing

Tags

• DSA
• ECDSA
• LLL

Exploit

This challenge contains two Attack Vector

1. Biased nonce attack on modified ECDSA Just Login as user -> attack on sign phase -> get privatekey -> getting the flag. solver: /solution/solver1.py
2. Biased nonce attack on DSA with waiting Flag (slow time) Bypass Session. That was leak from token. Just generate Encrypted Flag with minimum dataset is 7*5 tick. The Basis use is 2**16. Cost time estimately (>= 35 minutes). solver: /solution/solver2.py