siv2r / crypto-puzzle

My attempt at intresting cryptographic challenges

Description

Compilation of my solutions to cryptography-related challenges that I find interesting. Each challenge directory will contain a README file explaining the problem statement, build instruction, and solution approach.

Don't hesitate to reach out if my solution is confusing or needs a better explanation. In the future, I will write a blog about a few of my solutions (not my top priority at the moment).

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Challenges Solved

1. Bitcoin flavoured Crypto Challenges

Here's a Bitcoin-flavored cryptography challenge in the spirit of Cryptopals --by Elliot Jin (@robot_dreams)

• Challenge 1: Nonce reuse in schnorr signatures
• Challenge 2: Schnorr signatures using Linear Congruential PRNG
• Challenge 3: Rogue key attack on insecure multi-signature scheme
• Challenge 4: Shamir Secret Sharing

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Build Instruction

The README file of each challenge has the required build instruction.

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Gratitude

I am very grateful to my mentor Jesse Posner for helping me understand daunting cryptographic schemes. I learned so many interesting cryptographic concepts from our weekly meetings.

A huge shout out to Elliot Jin for helping me come up with a solution for the challenge 3.

crypto-puzzle's Issues

Rogue Key attack

Some context:

You're unnecessarily introducing an extra X3; what you want instead is to provide a modified X2' so that you know the private key corresponding to X1 + X2'.
BTW xonly keys are really annoying but don't actually add any security