Tuesday, 12 November 2013

Zeromutarts - the magic of rsa

Website : http://zeromutarts.de/

Question :
You were able to hear some whispering on the last crypto party! *whisper* d is 35181901. Keep it secret or we are doomed!

There are 2 files namely rsa.py and rsa.txt,you can download it from here..



I would suggest to read about RSA here in wiki

the parameters we know is n,e and d
oh wait!! what is d? look at the question.. d is 35181901

plain-text = (cipher-text)^d mod n

This is the formula.we know all the parameters.Ciphertext is the one in rsa.txt. I would suggest you to write it in a script because trust me you will learn a lot.

Anyway you could use this website as well :
RSA Calculator

substituting d,n and the ciphertext we would get

FLAG : you_got_the_basics_my_padawan

No comments:

Post a Comment

enter valid comments.Suggestions are most welcome and would be interested in correcting my mistakes.