I need to decrypt c and I was given only n, e and c and computing p and q or phi(n) would be close to impossible so what other alternatives do I have? I tried calculating p and q but I made very little progress with the search in the last 24 hours of continuous running the program.
These are the values I was given:
n: 58900433780152059829684181006276669633073820320761216330291745734792546625247
e: 65537
c: 56191946659070299323432594589209132754159316947267240359739328886944131258862

Also, in another challenge only c and n were given and the values were a lot bigger. Do you have any suggestions for that too?

9

2 Answers

Well, seems the questions are CTF related because the patterns of n, e, and c are weak numbers.

You can solved it with RsaCtfTool

python RsaCtfTool -n 58900433780152059829684181006276669633073820320761216330291745734792546625247 -e 65537 --uncipher 56191946659070299323432594589209132754159316947267240359739328886944131258862 

timctf{CENSORED}

Try this one but it need p and q. So I use the hand calculator to find p and q. Using Fact(n), ex: Fact(91)= 7x13, so p=7, q=13

Your Answer

Sign up or log in

Sign up using Google Sign up using Facebook Sign up using Email and Password

Post as a guest

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy