I was given the opportunity to attend BSides
Philadelphia and was able to compete in a CTF. I
took home 3rd place playing by myself. I meant to form a group but I didn’t get
around to it. The below is my write up for a couple of the problems I solved. I
forgot to do the write up while I was there, so I apologize for not sharing the
exact names of the challenges. I was also able to attend a couple of talks
there.
I had a bit of inspiration recently with Fermat’s Attack on RSA and
decided to make an RSA demonstrator. It shows all the steps in
performing an RSA encryption using 2 known primes. It might be useful
during a CTF when trying to determine small RSA keys by hand. I’ll
eventually post a follow up for implementing that attack for small p
and q.
A caeser cipher is a cipher that moves each letter by a fixed
offset. You'll see these as a common challenge in easier CTF events. So,
I wrote a tool to encode caeser ciphers and generic shift ciphers.
A caeser cipher is a cipher that moves each letter by a fixed
offset. You'll see these as a common challenge in easier CTF events. So,
I wrote a tool to encode caeser ciphers and generic shift ciphers.
This application decodes a unicode string into it's character codes, and names. It's meant to come in handy with CTF events.
You enter your string in the form below and it will print out a table with the decode of it. I created it because I found
it really difficult to find a decent decoder that gave me the actual codes.