CyberSecurity Rumble CTF 2020 | DLOG

Description 200 + 152 Points (13 solves) For this one you need to build a quantum computer unfort… nc chal.cybersecurityrumble.de 31782 Author: rugo|RedRocket Files: main.py Overview Reading the provided source code we can notice the server is using the secp256k1 curve: a = 0 b = 7 p = 0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f secp256k1 = EllipticCurve(a, b, p) Then the server asks us to provide a point and it uses as a generator:
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Fword CTF 2020 | Sign it!

I created crypto challenges for fword ctf 2020 edition and here is a writeup for one of them. It’s about a biased nonces for weak ecdsa signatures. Description 500 points (6 solves) nc signit.fword.wtf 1337 Author: KOOLI Overview Connecting to the provided nc service we can see we have two possibilities: See available commands: ls cat run.py Execute command: ls : flag.txt run.
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