Half way through the competition and we still have a lot of teams in contention for first place. WE also have had a flurry of new registrations and there are now 7481 users. Well done to all of you who discovered the cunning switch to a transposition cipher in Challenge 4A and managed to crack it.

Things will get a little tougher now, and it is a way to go to the finish line, but to keep spirits up teams that complete Challenge 5A successfully will be entered into a prize draw to win one of ten £25 prizes this week. Winners to be announced on Friday 25th November.

Good luck,

Harry

The Leader Board is up and you can find out how you ranked in the first main part of the competition. A great takeup for this round and you all did really well. Challenge 4 is definitely a little harder and from now on things will ramp up fast, but we are still giving you plenty of time to get full marks this week. Submit a complete correct answer before Midnight tomorrow (Friday) and you will get 100% and be joint first on the Challenge 4 Leader Board. As usual, if you are a little unsure about your answer submit it anyway but check your working and if you find a mistake before we start the feedback then resubmit a better answer. Your best answer is always the one we count, now the points contribute to your final score.

Round 2 done and we have an extraordinary 7115 registrations for the competition this year. Congratulations to all of you who cracked Challenge 2. Hope you liked the affine cipher (and Joan Clarke’s subtle hint in the forum.

Challenge 3 steps up the difficulty again, but anyone who tackled Challenges 1 and 2 should be able to manage this one, with a little patience. Now that half term is out the way you only have one week to tackle it and this time speed really matters. Challenge 3 is the first one which counts towards the final Challenge B leaderboard positions, and therefore counts towards the main prizes. Full points can be score on Challenge 3B up to midnight tomorrow so there is no rush to submit today, and you will only get full marks if you submit a complete and correct solution before the deadline, so take your time and get it right. As this challenge counts we will switch off feedback until the deadline has passed. If you think you have made a mistake before then just resubmit, but do remember that we discourage random re-submissions.

Good luck cyber warriors.

Harry

Challenge 3 is the first round of the competition that will count towards the prize rankings. Speed does matter, but accuracy matters more, and you have plenty of time to get your first answer in. The deadline for full marks in Challenge B is 23:59 on Friday 4th November. You don’t get any extra credit for getting it in before then, but as with all homework it is probably best not to leave it to the last minute in case there are problems. After that the points decrease, but you do have until 23:59 on Wednesday 9th November to submit and still get credit, points drop by 2 after 24 hours in this round.

The Challenge will be a little tougher than the first two, but given everything you have learned so far you should be able to crack it. Not making any promises like that for the rest of the competition though!

Good luck,

Harry