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vijayanandrp/Write up for InCTF 2014 - Crypto 200 - Solved RSA 4096 bit using low public exponent attack.txt

Created June 15, 2017 22:38
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Write up for InCTF 2014 - Crypto 200 - Solved RSA 4096 bit using low public exponent attack
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Write up for InCTF 2014 - Crypto 200 - Solved RSA 4096 bit using low public exponent attack.txt
11657667992152384389168970007935564620544078223989911116124095315088239681126594015781938080477630692915497593321366093615015306163688656393156198882654127506116466608834490674480387607410167266362059980939450825093071957288196553216860521023077321644076523737128658172831409622651074862
Never use a small public exponent in RSA keys. The recommended exponent is 65537. The key for this level is weakrsakey.
"""
ciphertext = pow(plaintext, 3) % modulus
# 'ciphertext' is the remainder, so all we need to know to take the cubic root is the quotient 'k'
ciphertext + modulus * k = pow(plaintext, 3)
"""
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