It needs also the Node-packages Express, Cookie-Parser,

Body-Parser and Crypto. They can be easily installed using the

Node package manager \texttt{npm}.

\item Here is another puzzle where you can practice thinking

      like an attacker: Consider modern car keys. They

      wirelessly open and close the central locking system of

      the car. Whenever you lock the car, the car ``responds''

      by flashing the indicator lights. Can you think of a

      security relevant purpose for that? (Hint: Imagine you

      are in the business of stealing cars. What attack would

      be easier to perform if the lights do not flash?)

      Should the car also make a ``beep noise'' when it

      unlocks the doors? Which threat could be thwarted

      by that?

\item And another one: Imagine you have at home a broadband

      contract with TalkTalk. You do not like their service

      and want to switch, say, to Virgin. The procedure

      between the Internet providers is that you contact

      Virgine and set up a new contract and they will

      automatically inform TalkTalk to terminate the old

      contract. TalkTalk will then send you a letter to

      confirm that you want to terminate. If they do not hear

      from you otherwise, they will proceed with terminating

      the contract and will request any outstanding

      cancellation fees. Virgin on the other hand sends you a

      new router and paperwork about the new contract.

      Obviously this way of doing things is meant to make

      switching for you as convenient as possible. Still can

      you imagine in which situations this way of switching

      providers can cause you a lot of headaches to you? For

      this consider that TalkTalk needs approximately 14 days

      to reconnect you and might ask for reconnection fees.

\item And another one: A water company installed devices that

      transmit meter readings when their company car drives

      by. How can this transmitted data be abused, if not

      properly encrypted? If you identified an abuse, then how

      would you encrypt the data so that such an abuse is

      prevented. Hint: Consider the fact that every person

      uses approximately 120l of water every day.

\item And another one: Nowadays everybody is scared at a bomb

      going off at a big event, say a football game. To

      mitigate such a threat, you order expensive metal

      detectors and hire a security team that will staff these

      detectors at each game. Think whether people are really

      safer at a football game with metal detectors or not.

      Hint: People certainly might *\emph{feel}* safer by

      going through metal detectors, but the question is

      whether they *\emph{are}* safer. Hint: Consider how

      people arrive at such an event: within a relative short

      amount of time, thousands, if not more, spectators will

      arrive at your football game.