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Cake day: July 1st, 2023

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  • If the timestamps line up, maybe Wireshark just doesn’t manage to understand the entire exchange. What could happen is that Wireshark sees the SSH handshake, and after that it might become just encrypted gibberish due to the encryption. In that case the SSH traffic could just show up as “some kind of TCP”.

    Do you see an SSH handshake, followed by random crap on the same ports?

    (I’m not a Wireshark expert, just an IT guy trying to help!)











  • The function should be cubic, so you should be able to write it in the form “f(x) = ax^3 + bx^2 + cx + d”. You could work out the entire thing to put it in that form, but you don’t need to.

    Since there are no weird operations, roots, divisions by x, or anything like that, you can just count how many times x might get multiplied with itself. At the top of each division, there are 3 terms with x, so you can quite easily see that the maximum will be x^3.

    It’s useful to know what the values x_i and x_y are though. They describe the 3 points through which the function should go: (x_1, y_1) to (x_3, y_3).

    That also makes the second part of the statement ready to check. Take (x_1, y_1) for example. You want to be sure that f(x_1) = y_1. If you replace all of the “x” in the formula by x_1, you’ll see that everything starts cancelling each other out. Eventually you’ll get “1 * y_1 + 0 * y_2 + 0 * y_3”, thus f(x_1) is indeed y_1.

    They could have explained this a bit better in the book, it also took me a little while to figure it out.