Noise in the Air

Josh Marron, Jay Pottharst


The first task is to crack the encrypted files. Assuming you're a little bit familiar with how RSA works (or, is implemented in openssl), here is a sketch of the steps.

First file. The numbers, and the steps to get them, are

One can either directly attempt to use these to decrypt the .bin files, or make a sample 110-bit .pem file and overwrite its bytes with (the hex of) the data above. Using the resulting 1private.pem file together with "openssl rsautl", one gets: These give "exponentiate".

Second file. Only the numbers this time.

Overwriting a sample 185-bit key with all this to get 2private.pem (say), and using this to decrypt, we get: For a total of "position index by".

Third file. Make sure you got a very good factorization program.

Same with a 225-bit key to get 3private.pem, and decrypting gives:

So... you have been instructed to "exponentiate position index by 2003". So make a new file, where we take each ith character of noise.txt, and put it in the i2003th position of the new file. The resulting file has size 180991 = 241 * 751 (both prime), so there are only two ways to make the text into rectangles. One of these makes the text into a large "bitmap" of a turtle.

Answer: TURTLE