It's more than half-way through term already! We're continuing our talks this week with a talk about encryption on the internet, and we also have Film Night on Friday.

There's also a solution for the "The Crystal Maze" puzzle from last time, and make sure you have a go at the new "The Hidden Coins" puzzle! Get in touch if you think you've worked it out.

Talk - "The Life And Times Of HTTPS" by Marks Polakovs - 19:15, Thu 05/11

Fifteen or twenty years ago you'd have been a fool for signing in to your MySpace account on any internet connection except for the one at your home. All your account details were sent unencrypted over the wire, ripe for anyone to steal. Today, however, over 80% of all connections Firefox makes are encrypted, and with every day we get closed and closer to universal encryption. How did we get here?

In this talk I'll build up the HTTPS protocol from first principles and go over the changes it has seen over its life, the neverending battle between attackers and browser vendors, as well as the seismic shifts in the certificate authority landscape that have enabled adoption to more than triple in just the last five years.

Film Night - 19:00, Fri 06/11 - HackSoc Discord (The Pod)

We gather together in our Discord server to watch a film (or sometimes several). Apparently some of these might have a link to Computer Science, but we haven't spotted one yet.

Vote for the film you'd like to watch using our Film Night Portal!

We'll use our very own live-streaming platform to watch the film together. Hop into our Discord server at 7pm, and the film will begin after some time to catch up with your fellow members. (If you wouldn't like to hear any conversation during the film, then you're welcome to mute and deafen yourself!)

TODO TODO TODO PASTE THE IMAGE HERE IN GMAIL TODO TODO TODO

Above is one solution, there are more.

Bonus: an effective way to write a program to solve these kinds of problems is using constraint solvers/optimisers. For instance, using Savilerow one can implement the problem as follows:

TODO PASTE THE CODE

Which can take a parameter file such as the one below which describes the version of the problem from the initial question.

TODO PASTE THE CODE

Which can give a solutions like:

TODO PASTE THE CODE

Note: due to the constraints of Savilerow we have mapped A->1, B->2 etc.

We can extend and adapt this to make a system which can generate problems, or a system which can optimise for particular variables. If this seems interesting consider taking CONS if doing an integrated masters, or as an elective in 3rd year.

Imagine you have a box in front of you.

In this box there are ten coins. Five of these coins are heads up, and five of them are tails up.

You can reach into the box, without looking inside, and perform the following actions:

• Move coins between piles, including creating new piles or merging existing piles.
• Flip one or more coins so the opposite side is now showing.

You must create two piles of coins which each have the same number of heads up and tails up. For instance, two piles each with two heads facing up and three tails facing up.

You can only look inside the box and check you are correct once you are done.

Is this possible to do consistently, and if so how?

Make sure you're in HackSoc's Slack workspace! We have over 200 members, and it's free to join the conversation, so sign up now!

If you're joining us for any of our virtual events, make sure you're also in our Discord server.

Have a great week,

Aaron 🤖