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Budgets are tight for everyone so we get asked this a lot. The good news is it will cost nothing. For fifteen years we have been lucky to have several generous sponsors, and the costs of the competition are covered by the School of Mathematical Sciences at the University of Southampton.

Registration opens on September 15th. The first part of the competition will be published at 3pm on Thursday October 5th. There is no need to rush to download it as you have one or two days in which to submit to achieve full speed marks. Often the website is overloaded for the first half an hour or so, and it probably pays to wait out the rush. The part B prizes will be allocated based on performance in rounds 3-8 so if you miss the first couple of challenges it won’t matter too much.

The challenges are published on Thursdays at 3pm. There are 8 rounds and they are scheduled as follows:

Challenge 1, published at 3pm on Thursday 5th October
Challenge 2, published at 3pm on Thursday 12th October
Challenge 3, published at 3pm on Thursday 19th October
Challenge 4, published at 3pm on Thursday 2nd November
Challenge 5, published at 3pm on Thursday 9th November
Challenge 6, published at 3pm on Thursday 16th November
Challenge 7, published at 3pm on Thursday 30th November
Challenge 8, published at 3pm on Thursday 14th December


Please note that there are two week gaps between Challenges 3 and 4 and between Challenges 6 and 7 to accommodate half term and to give you all a rest before the final run in! We know that not all schools have the same dates, and it is impossible to accommodate them all, we hope you understand. It is possible for Team Captains to submit their solutions from anywhere with internet access so they should still be able to take part if their school is not open, and the Team Captain can always delegate that role (using the team page) if they are going to be away. There is also a two week gap between Challenge 7 and Challenge 8, but that is for entirely different reasons – Challenge 7 will be hard, and you might need it.

The deadline for each Challenge is 11.59pm on the day before the next Challenge is published, The number of points you score in part B depends on how early you submit your best attempt, but your score for part A is not time dependent. The points schedule for each challenge is linked from the Challenge page.

Principally this is an extension activity for older pupils, but the early stages of the competition are aimed at a wide audience and there is something for everyone. We have had bright year 6 pupils do well on early rounds and this prepares them for further achievement in future competitions, though the challenge is definitely not designed or intended for the junior school age group. Many pupils return year after year as they try to improve on the number of stages they can successfully complete, and the staged certificates give everyone an incentive to keep going as long as possible.

Certainly. The entire math club could enter as a team or you could divide up into smaller groups and use the math club meetings to discuss techniques and strategies. The Resources page is full of useful materials for a Maths or Codebreaking club.

Yes, we get many solo entrants and teachers do not have to be involved, but we do ask for the contact details of a teacher or Parent/Guardian contact for prize administration.

No, in the past we have had several teams made up of members of different schools and colleges, and this is great. We do ask for the name of at least one of the schools and a teacher contact for prize administration, and, for now at least, the team captain’s school will get all the credit!

No, we do not split the competitors by age group and mixed age groups can work well with the older team members training up the younger ones for future success.

No, but everyone can have one! If you are taking part on your own you only need to register and create a team of 1 with you as Captain.

If you want to enter as a group the Team Captain should sign up for an account. Team members should then register for accounts and select “Join an existing team”.

If you need or want to change your team you can do so, but you will not take your score with you. That remains with your original team and you will become part of the new team with its existing score.

The website is stocked with information about the competition, including this FAQ,  the About the Challenge page, the Rules and Regulations, and our news on the Stay up to Date page.

There is more infomation on our Resources page including notes on codebreaking, some class materials and a guide to programming for codebreakers.

It is also worth taking part in the forums, which we will monitor and where we will publish occasional updates and answers to common questions. Be kind to the Elves who staff the Forum. They work very hard to support you and can’t always answer queries immediately (it is, in elf terms,  getting close to Christmas and the sleigh needs packing).

If you are a teacher who is registering in order to keep an eye on the forum, or a Cipher Challenge alumnus who is now too old to take part but just can’t keep away, or ineligible for some other reason, then please tick this box so that the computer doesn’t award you a prize by mistake! It is embarrassing for us to have to ask for it back. Thanks.

Best to let them answer that! Julian Bhardwaj took part for many years, going on the study Discrete Mathematics at University and to be a finalist in the UK Cyber Security Championship. He said of the competition:

If I were to name one thing which has undoubtedly influenced my academic drive, interests and overall career to date, it would be the National Cipher Challenge. Since being introduced to cryptography and the challenge in Year 8, it has been my one passion and driving force in pursuing further education in maths.

Not all of the competitors like to work alone and teacher Claire West from Peter Symonds College saw the benefit of team work

As a teacher, I see the students form themselves into successful teams; with self-elected leaders who are responsible for organising their group after identifying their member’s individual strengths.  In our college, the challenges are worked on entirely by the groups alone as they use our library to work past the usual college close time.  I am so proud of them.

One of her team members said:

You can take it as far as you want. I loved it and read books about ciphers got addicted to solving the challenges. It builds up to the more complex challenges so every week you know you’ll get stretched just a little bit more. I went back multiple years to try and beat my score from the year before. It was great fun, solving the challenges as a team and actually applying the mathematical skills you learn in maths. I loved it and I’m sad I can’t do it again next year!

If you are taking part on your own you need to register and create a team that will have just you in it. The team name can be set on this page:

If you want to enter as a group the Team Captain should register first and create a new team. The Team Captain can then send the team members a link to their team from this page: Team members can then use that link to request to join the team. The Team Captain will receive an email on each request and they can then accept or decline invitations from the team tab on the Team Captain’s account page. The team name can be set by the Team Captain editing the name on the Team page under your account.

If you wish to join a team after you have already registered then you will need to change your team. Do this by using the “Change Team” form on this page: Your new Team Captain will need to accept the invitation.

Use the answer boxes on the Challenge page. You will only see this if you are the Team Captain, as only they can submit your answer. If you are not the Captain you will see a reminder of this. If your Captain is not going to be available to post the team submission for a particular round they can either delegate another member of the team as Captain, or give a deputy the Captain’s login username and password so they can submit instead. If you think you might need to do that there are things to be aware of. The erstwhile Captain cannot just take the Captaincy back, they need the new Captain to delegate it back to them. And if you share your account details then whoever knows them can post on the Forum as you.

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You don’t, you have the option to say neither, or “Prefer not to say” and we are happy with that. However this year we are honoured to introduce the Ada Lovelace Prize for best female code breaker, sponsored by BCS. It would be a bit difficult to award it without knowing who qualifies. We recognise that “neither” could look a bit dismissive and we did consider a range of other options, but in practice we don’t need to know so probably shouldn’t be asking, though that might change in the future. Another good reason to collect this data is to get a picture of what the National Cipher Challenge community looks like so we will use this data, in aggregate, for reporting purposes, but we will not share it with anyone else.

Anyone who has been following the National Cipher Challenge since it started will realise that either Harry is very, very old (and surprisingly sprightly for his age) or he has a time machine. Possibly both. He also has a PhD in Mathematics which makes him feel rather a lot like the Doctor, a comparison he does nothing to discourage. The Elves who run the forum however, violently reject the idea that they are in any sense “Companions”, and anyone who has seen an Elf fighting their way through a horde of Orcs will know that it is never wise to anger one.