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Cryptography Competition.
(edition 2015: #4).
You are reading the website of the 2015 edition of the competition, which ended on Wednesday 13th May at 11:59 pm. We are planning to run a new edition next year, to start in January 2016. The website for that new edition appears in December here. If you would like to receive a reminder around that time by email please look here. For any particular enquiries you can contact us on cryptography_competition@manchester.ac.uk.

The Alan Turing

Cryptography Day


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Chapter 6 of the Tale of the Carbon Conundrum.

The MaliOpus Industries headquarters glistened in the Manchester rain. It appeared to reach up into the clouds. "Appropriate given their corporate slogan," muttered Ellie. "Now how are we going to get in?"

A taxi pulled up outside the headquarters. Two identical brightly coloured raincoats got out and ran up to the entrance. "It can't be", said Mike. "It's Darcie and Donna!" replied Ellie, "I'd recognise those raincoats anywhere. What are they doing here?"

As Mike and Ellie entered the building, they saw the twins go through two double doors marked `Conference Room'. "We're with them!" said Ellie to the receptionist.

As they approached the conference room doors, they could overhear Lord Porterfield talking.


"Where is the quantum computer?" demanded Lord Porterfield. "Without it, this company will be ruined."

"It's right here, Uncle!" said Darcie. "We're still your favourite nieces aren't we?" wheedled Donna.

"You're my only nieces!" raged Lord Porterfield. "I need that computer - without it, this company will be ruined! You know we have no research department. The whole company is built on a lie: we obtain all our technology illegally from others, wrap it up in fancy marketing, and sell it to the public at extortionate prices. But we need a new product urgently: without it, the company will go bankrupt within the month! The company's future - your inheritance - depends on that computer!"

"About our inheritance," said Darcie. "We've decided we want it a bit sooner. Do you remember how you put MaliOpus Industries in our names as a way of dodging tax? Well, we've been speaking to our lawyers and we've decided to take control of the company." "You see," they added in unison, "we're far smarter than you!"

Lord Porterfield's face grew furious. "In fact, we've recorded your part of this conversation," said Darcie. "I'm sure the police will be very interested to hear it", added Donna. "Security!" they both yelled, as a security guard came in through a side door to take Lord Porterfield away.


"I think it's time we made ourselves known," said Ellie, as she and Mike entered the conference room.

"We thought you might be here," said Darcie. "Do you like our new company?" said Donna. "We thought it was time for a change of leadership: we were tired of doing Uncle's dirty work for him."

"But how did you steal the quantum computer?" asked Ellie. "And why wasn't it found when the building was searched?" asked Mike.

"It was easy!" they both said. Darcie went on to explain: "Everybody was so excited when Niemand let us into the laboratory. We all rushed in, and when it was time for the next group, we hid at the back as everybody rushed out. Niemand didn't have time to count everybody accurately, so he didn't notice. We took the quantum computer and hid just behind the entrance. As Niemand opened the door again, we just joined the crowd as the next group rushed in. Niemand was in such shock to see that the quantum computer had gone, he didn't have chance to see that there were now two extra people in the group!"

Donna continued: "Uncle had told us that security would be tight and we wouldn't be able to smuggle the computer out of the building. So we went to hide it in Niemand's office. That was a stroke of luck: his office is such a mess with so many piles of papers and books that nobody - not even Niemand himself - would be able to find it!"

"Although Niemand did nearly catch us. Once on our way to Uncle's lecture just after we'd hidden it, and again when we sneaked in to his office recover it."

"Niemand's a fool", said Darcie. "We're far smarter than him - and you!"

Ellie looked at the quantum computer on the conference room table and winked at Mike. "You may be smarter. But are you faster?" she said, as Mike grabbed the computer and they ran straight out of the building, leaving the twins rooted to the ground in shock.


A safe distance from the headquarters they paused to catch their breath.

"We've got the computer, and I don't think Lord Porterfield will be troubling any one for quite some time," said Ellie. "But we still don't know why Niemand tried to assassinate him. And why did Barquith sacrifice his life to save him?"

At that moment, both their phones bleeped. "It's an email, but it's just a string of 0s and 1s," said Mike. "Same here", said Ellie. "But look, mine's not the same as yours. I wonder who they're from?"

Click here for a larger version of this image. Click here for a larger version of this image.
Your task:

Above are images of the emails to Mike and Ellie. Your task is to find the hidden message. Once you have done that, submit your answer to the question below.

Question: What is the 9th word of the plaintext?
Your answer:

You can not submit your answer since the Competition has now closed.