Tags: cryptanalysis 

Rating: 4.0

crypto warm up challenge

myrdyr – Sept. 4, 2017, 8:34 a.m.

I solved it in a similar way, by guessing that the flag was part of the plain-text. Discovering this, it was possible to recover small chunks of length 6, followed by 7 unknown. Decrypting with that, I recovered parts of the appended key that I did yet know. Applying that key to what I knew, I discovered the rest of the key and could decrypt.