PicoCTF_2017: SmallRSA

Category: Cryptography Points: 120 Description:

You intercepted a single message. However, it appears to be encrypted. Can you decrypt it? Message


Normally, you pick e and generate d from that. What appears to have happened in this case? What is likely about the size of d?


This challenge is an implementation of Wiener's RSA attack. I would like to give credits to pablocelayes for his wonderful library for this attack. He saved me from doing math.


Therefore, the flag is flag{Are_any_RSA_vals_good_95979862524}.