Recover RSA private key from public keys - rhme2 Key Server (crypto 200)

Показать описание

Using the greatest common divisor (GCD) to factorize the public modulo into the secret primes, so we can forge a RSA signature.

-=[ 🔴 Stuff I use ]=-

-=[ ❤️ Support ]=-

-=[ 🐕 Social ]=-

-=[ 📄 P.S. ]=-

All links with "*" are affiliate links.
LiveOverflow / Security Flag GmbH is part of the Amazon Affiliate Partner Programm.

#CTF #Cryptography

Рекомендации по теме

Комментарии

For anyone using python 3+ you will want to do q = n//p since one division operator results in an approximated float and will lose some precision resulting in a wrong q.

jb

It's so unbeliveable that people are smart enough to create things like this that just work. It always blows my mind...

cyancoyote

Ironic. For my job, I watched a lot of videos about why and how RSA works. Some more mathematic - some less. But the best explanation comes from a video about how to break RSA...
Thanks LiveOverflow

Mindflayer

this episode was really impressive, well done!!

lilpp

The technical aspects still go over my head, I'm new to this. But your thought process man, that's gold. Thanks for sharing and keep it up!

rafnd

This challenge was based on CVE-2008-0166 (Debian Security Advisory DSA-1571-1).

mynewrandomhandle

Seccon 2017 had a same type of ctf problem, and it was the first ctf problem i had solved on my own, your videos is where i started my journey into RE and ctf and stuff. Keep up the good work.

rafid

Reminds me of RSA challenge which I faced in a CTF and I had no idea how was this RSA thing working but thanks to you. I got clear concept about RSA 😃

nirmalthapa

0:14 This somehow consistently activates my Google Assistant, even though I myself have trouble doing it.

hecko-yes

Awesome video. Going to have to watch it again to digest it (unintentional crypto pun.)
Tip: put a hyphen between bullshit and free, ie. bullshit-free, or else it might imply that is is both bullshit and free, instead of being free of bullshit.

typedeaf

Great video man ^^ Hope you got some more vids about cryptography like this one heheh

mistsu

Discrete math <3 Euclid used a stick on a number line to demonstrate modulo in the elements pre 300BC

Zzznmop

I learned so much with this video, great one, thanks!

Bubatu

You are the man. Great video again, as always. I would have never thought to use GCD. Just curious, did that take a long time to compute the GCD, or was that result real time?

Salmiery

I heard about some news that the "Shor Algorithm" will be able to crack all Public keys Encryption methods but you'll need a Quantum Computer for that which nearly nobody has.

MrLePiggy