## GCHQ Puzzle Book II Solutions

This will be an ongoing page that I will update as I make more progress.

# Centenary Trail

## Known Structure

A Very Straightforward Puzzle and Grid

Copyright Page

Penguin Puzzle

Inside Front Cover

Regex Crossword

Unknown

Inside Back Cover

Obfuscated Code

Puzzle Hunt

Unknown

Resistance is Futile

How to do a Cipher

Games

Unknown

Alphabet St.

A Century

Puzzle | Solution | Year | Ciphertext |
---|---|---|---|

Straight Forward and Grid |
Copy Right Page | 1988 | IXEZZFCGCZABZ |

Copyright Page | Penguin, Puzzle, Multiply, 4,?,?,? |
=4*?*?*? | |

Penguin Puzzle | INSIDEFRONT1940 | 1940 (1941?) | QKTTXXSIBXNFQ |

Inside Front Cover | REGEXCROSSWORD | 2002 | |

Regex Crossword | ? | 1977? | CAVAFQNTKZNQT |

? | |||

Inside Back Cover | YEAR NINETEEN SIXTY THREE TAKE PUZZLE TRAIL TO OBFUSCATED CODE |
1963 | |

Obfuscated Code | the.puzzle.hunt.continues.the.year.is. mcmxciii |
1993 | PZSCCNCTNAKBR |

Puzzle Hunt | ? | ? | |

Resistance is Futile | Congratulations. To continue the centenary trail you must now go to the how to solve a cipher section |
1930 | ZFQCYQNYPFNCN |

How To Solve A Cipher |
Games Puzzles | ? | |

Games | ? | ? | CSBWQTVFQBQAA |

Alphabet St. | GO BACK, A CENTURY |
2019 | TBVNTPBFCAKZF |

A Century | ? |

## Solutions

### A VERY STRAIGHT FORWARD PUZZLE

This is a substitution cipher and the title text was hinted at in bold on the page before. The penguins in space helmets denote spaces. Decoding the penguins in the picture we get the letters and spaces to make NINETEEN EIGHTY EIGHT.

### Grid

The word that let me fill in the rest was the word EQUAL because I suspected Q needed to fit with QUICK. Here’s the grid:

The missing words are Copy, Right and Page.

### Copyright Page

There are some lists which are odd ones out.

Chameleon, Gibbon, Jackal, Kangaroo, Lizard, PENGUIN, Rhino, Scorpion, Tarantula, Vulture- All Spider-Man villains apart from The Penguin who is from Batman

b(y)ellow, d(y)awning, f(y)east, f(y)ield, h(y)elped, l(y)earning, m(y)odel, m(y)outhful, p(y)onder, PUZZLE, Words which can exchange their first letter for a Y.

delPHI, macrobIOTA, mariaCHI, MULTIPLY, parveNU, pePSI, scamPI, taXI, taffETA, Words ending in greek letters.

So we have to go to the Penguin Puzzle next. To get the year we should multiply the four numbers below. Each list is increasing but doesn’t include every number of the specified type. For example the Fibonacci list doesn’t include 13, 21, 34 or 89.

1, 2, 3, (4), 5, 8, 55, 144, 233, 377 Fibonacci Numbers

2, 3, 4, 6, 9, 15, 55, 90, 200, 1010 ? Can’t be 90, 200 or 1010 because they give a year which is too big. Lots of factors.

3, 6, 7, 10, 21, 22, 30, 33, 35, 36 It looks like a of things, like Monarchs, States or Presidents. Maybe this sublist have something in common? Presidents are probably out because of Grover Cleveland (he was both 22 and 24). Monarchs who were first of their name?

1, 4, 5, 8, 10, 23, 46, 61, 84, 5000 ?

### Penguin Puzzle

Naming each species and taking the letter which corresponds with the number of penguins in the picture gives:

afr(I)can

ge(N)too

(S)nare

ch(I)nstrap

a(D)elie

(E)mperor

(F)iordland

(R)ockdweller

macar(O)ni

ki(N)g

li(T)tle

Then taking the number of penguins in the remaining four pictures we get 1940

This takes us to inside the front cover.

### Front Code

Each line has the same phrase repeated again and again. However there are little errors as the same sequences are repeated. Highlighting the last time a letter appears before it disappears, or the last time it occurs by itself before it is duplicated, we get:

Colouring in between each pair of highlighted letters, we get 2002. The next location is given by taking each letter that the arrows point to: REGEXCROSSWORD. I was definitely overthinking this one.

### Regex Crossword

I’m part way through this one. I’m pretty sure the year is 1977 but I’m having to look up a lot of Regular Expressions along the way. Here’s a brief intro.

### Alphabet St.

Going through the maze we get GOBACK.

T̶h̶a̶t̶ ̶t̶e̶l̶l̶s̶ ̶u̶s̶ ̶t̶h̶a̶t̶ ̶t̶h̶e̶ ̶n̶e̶x̶t̶ ̶p̶u̶z̶z̶l̶e̶ ̶i̶s̶ ̶g̶o̶i̶n̶g̶ ̶t̶o̶ ̶b̶e̶ ̶a̶t̶ ̶t̶h̶e̶ ̶b̶a̶c̶k̶ ̶o̶f̶ ̶t̶h̶e̶ ̶b̶o̶o̶k̶. (I got this wrong. Thanks reddit.) Taking it as an instruction for the puzzle we can try again but starting at FINISH and ending at START. This gives ACENTURY2019, so our year is 2019 and the next puzzle is A Century.

### Resistance is Futile

There was a problem like this from GCHQ recently and I wrote it up here. Each resistor cluster can be reduced using series and parallel considerations along with the occasional delta-Y transformation (explained on the previous link).

Reading these resistances as coordinates both down then across and across then down we get these messages:

The year for this puzzle is nineteen thirty

This is not the message you are looking for!

Taking out the letters you have used you get a substitution cipher which gives:

Which tells us to go to The How to do Ciphers Section.

### The How to do Ciphers Section

There are three ciphers to solve. The first is a caeser shift (rot13) which translates to:

The second is a keyword cipher which translates to:

The keyword is: Games Puzzle which confirms that the puzzles in the picture insert are not in order.

The third is a poem cipher which will give the year. Working on this.

### Games Puzzles

I think each puzzle gives a grid reference to read off the sudoku.

Chess-

Poker-D5

Mornington Crescent-

Bridge-

Battleships-E2

Hangman-H(eight)

Cribbage-

### Inside Back Cover

This is similar to the front cover in that it has repeated phrases. Highlighting the errors in the same way we get 3 highlighted rectangles.

Reading the text in a spiral we get:

Read the floating rectangles in this order

Third rectangle has a substitution applied

Ysal hmhspssh nmxpy pglss pacs jqzzds plamd pi iueqtapso tios

Which translates to: YEAR NINETEEN SIXTY THREE TAKE PUZZLE TRAIL TO OBFUSCATED CODE

### Obfuscated Code

This code is not too dissimilar to the enigma cipher and it gives you the output with the mapping seed and you have to work out the input. One of my students wrote me this piece of code in Python to decode it: google doc link.

It gives: “the.puzzle.hunt.continues.the.year.is.mcmxciii” So 1993 and now we have to solve the entire Puzzle Hunt which is made of 10 picture puzzles which come together to form a meta answer.