And so it starts. The first Challenge will be posted in The Black Chamber at 3.15 this afternoon. The website will go offline at approximately 2.45pm to allow us to upload the ciphers. From that page you will be able to download a pdf of the Challenge to work on offline. You will also see a link to the entry form which you will need to complete to submit your entry. There is no rush to submit this first Challenge. Any correct submission before 11.59pm on Friday 6th Oct (tomorrow) will get full marks. After that the marks available go down slowly (see the Standing Orders for more info). So do not panic if the site is busy or slow when you want to submit. The same goes for obtaining the Challenge. If this site is unresponsive (we have a LOT of people looking at it today) then you can obtain the pdf version of the Challenge directly from this backup. You might want to bookmark this link now in case there are problems later. We will send out feedback on your submission by email overnight. If you have made a mistake you can resubmit, but please do not send lots of attempts at the same time. This strains the system and is against the rules.

We are overwhelmed by the numbers signing up this year, it is great. It would be even better if we could get an accurate idea of how many of you are taking part so we have added an item to the registration form asking for the number in your team. If you have already registered could you log in and add that info to the team page in "Your Account" info. Thanks

If you registered but have not received an email from us it is possible that you gave an incorrect email address when you registered. Please log in and check it. If you have forgotten our password you can use the form to ask for a new one, but if you have given an incorrect email address (or if your inbox is full) you won't receive it. If this is the case please re-register. If you have registered but have not yet logged on to the site you may receive an email from us asking you to do so. This is so we can check which accounts are live and will give you a chance to make sure you know your password before the competition starts on Thursday. The server will be down for maintenance for a short while this evening, so please bear with us if you cannot load the pages at that time.

You may well have heard of the code breakers in World War II and the German Enigma machine, but did you know that Britain had a team of cryptanalysts in World War I who intercepted a coded telegram from the Germans in 1917? This telegram, which was sent to the German minister in Mexico, stated that Germany was going to lauch a submarine attack on the USA and if Mexico joined them it would be rewarded with three of the American states. This was one of the key events which led to the USA joining the war on the side of the Allies.