The second cryptanalysis challenge in the Ksi sequence is now up at https://github.com/eleemosynator/challenges/tree/master/ksi.
It's an updated version of the Ksi cipher, but still pretty easy to crack.
challenges/ksi at master · eleemosynator/challenges

Reverse Engineering and Cryptanalysis challenges. Contribute to eleemosynator/challenges development by creating an account on GitHub.

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