This year InCTF Quals really went well and I feel extremely privileged to be a part of it and conduct it. I hope everyone learned a lot more stuff after this CTF. This blog post covers the intended solution of the challenge that I created: MultiPrime RSA. It was a medium level challenge with 3 … Continue reading Inctf Quals 2018-MultiPrime RSA WriteUp
Category: RSA
Revolutional Secure Angou WriteUp
CTF: TWCTF 2018 CATEGORY: CRYPTO POINTS: 154 This blog post is for discussing the exploit of the challenge Revolutional Secure Angou. We were given the following ruby script When we go through the above code, we can see that the prime q is generated in a different way rather than usual. q = OpenSSL::BN.new(e).mod_inverse(p) On … Continue reading Revolutional Secure Angou WriteUp
Common Modulus Attack
In this blog we are going to take a look at one of the popular attacks on RSA, Common Modulus Attack. As the name suggests, this attack works when a common modulus but different encryption exponents such that their gcd is 1 are used. Let us consider a scenario for better understanding. Person A wants … Continue reading Common Modulus Attack
RSA
RSA (named after Rivest - Shamir – Adleman) is a popularly used public key encryption system. Security of RSA is based on the fact that it is very difficult to factorize a very long integer into its prime factors. Being public key crypto system, it involves the usage of public key and private key for … Continue reading RSA