Cryptoquest

As a child I was fascinated by detective or adventure books, in which heroes had to break ciphers and extract hidden messages from a completely innocent-looking text. However, even now the beautiful cipher and the winding path that the hero comes to unraveling it makes my heart beat more often :-) This is partly why I started watching the Stanford online course “Fundamentals of Cryptography” in June. The very first practical task (breaking the cipher of a one-time notebook, used carelessly more than once) delighted me and pushed me to create my own zip quest on the history of cryptography — on ciphers that are not used in our time in our time, but which so fun to hack by hand - or almost by hand.



Actually, here is the quest itself . The principle is the same as in the New Year's quest : at each level, the task is given in the form of a text file, deciding it (that is, hacking the cipher), we get the password to the archive, which contains the next level. Archive zero (cryptoquest.zip) without a password. In each case, not only the password itself is encrypted, but also a fairly long meaningful message - otherwise the cryptanalysis becomes too time consuming.



The quest turned out to be small (6 tasks) and not very difficult. As intended, it should be a prelude to a large and complex quest based on ciphers from my favorite works of art. I hope you will like it.



PS The presence of bugs is not excluded; write in a personal, correct, update.

')

PPS Quest passed at least one person (maybe more, but only one admitted), so we can assume that there are no bugs.