A collection of write-ups for challenges from the Cyber Apocalypse 2021 CTF finished by Kiril Blagoev.

After we get an intuition about phase kickback, we start getting into actual Computer Science, through building a State Machine, and recreating an actual Quantum Algorithm.

For the majority of our time spent programming on the quantum computer, we will be thinking of the qubits in their state of superposition. What would be useful for our intuition now, would be to have a way to visualise this superposition, so we can analyse the effects each logical gate has on it.

Just as we know that in classical computers we manipulate logical zeroes and ones, we can get an idea of what we are dealing with in the lowest level of logic in a quantum computer.

It's just like remembering where a distant house at an edge of a field is, then moving around the field, and checking where the house is now relative to us. If the house was distant enough, and coincidentally always north of you, you would call it the polar star.

The standard Vicsek model suffers from one weakness: it lacks an inertial term, which seems to be important in imitating the behaviour of biological systems. So the goal of this post will be to figure out a way to simulate the Vicsek model with time delay.

Both flocks of birds and swarms of insects exhibit properties one would expect in an organised group of creatures, i.e. they know of each-other, and act accordingly.