28 lines
895 B
Markdown
28 lines
895 B
Markdown
# blinkpdf
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## Author
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[wondPing](https://github.com/fixxall)
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## Description
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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.
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attachment: https://drive.google.com/drive/folders/1u05M-eq50ZJjO7Ww4EHWBYeHJH6zyFCC?usp=sharing
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## Tags
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- DSA
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- ECDSA
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- LLL
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## Exploit
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This challenge contains two Attack Vector
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1. Biased nonce attack on modified ECDSA
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Just Login as user -> attack on sign phase -> get privatekey -> getting the flag.
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solver: /solution/solver1.py
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2. Biased nonce attack on DSA with waiting Flag (slow time)
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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).
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solver: /solution/solver2.py
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