The class I’m most excited about this semester is Computer Security. Our first project was modeled after Capture The Flag contests where you have to pass level N-1 to get to level N, etc. It was a straightforward assignment: 4 levels and brute force our way to find all 4 flags.
The first two levels were files encrypted with dictionary words and easy to decrypt. The third level was bit more involved i.e. some steganography and encoded text contained in an encrypted file while the fourth was an encrypted file contained in an encrypted file. Thankfully, the steganography was more of stuffing extra metadata into the image than modifying the least significant bit or any of the most complex steganography tactics. Also, on the recommendation of our professor, I used the nice python-gnupg module to do much of the heavy lifting. There’s a Java library out there that integrates with GPG but I haven’t been able to make sense of it.