ctf_aria

write up ctf by ariafatah

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Project maintained by ariafatah0711 Hosted on GitHub Pages — Theme by mattgraham

soal

What happens if you have a small exponent? There is a twist though, we padded the plaintext so that (M ** e) is just barely larger than N. Let’s decrypt this: ciphertext

hint

• RSA tutorial
• How could having too small of an e affect the security of this key?
• Make sure you don’t lose precision, the numbers are pretty big (besides the e value)
• You shouldn’t have to make too many guesses
• pico is in the flag, but not at the beginning

solve

wget https://mercury.picoctf.net/static/a24cf907007a19dbf30310acad0df9e5/ciphertext

flag