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In place of your traditional chocolate advent calendar (or even as well as), we're going to be publishing a cryptic puzzle every day between now and December 12 to put your brain power to the test.

Each of the puzzles come from The GCHQ Puzzle Book, published by Penguin, which features more than 140 pages of codes, puzzles and challenges created by GCHQs code breakers.


Each day, the latest puzzle will be published below, so you can bookmark this link and see all the previous days' puzzles, listed by date. At the end of the 12 days, print off the puzzles and challenge your family and friends over Christmas!

The challenges range in difficulty from easy to complex and over the coming weeks, a selection of these will be posted with the answers available the following day. All answers will be available at the bottom of this article, as well as clues if you get stuck.

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Challenges include ciphers and substitution codes, tests of numeracy and literacy as well as picture and music challenges. The book itself has tips on how to think like a GCHQ puzzle setter as well as hints.

In previous years, director Robert Hannigan released a cryptographic Christmas Card. Last year, 600,000 people globally took part in a challenge, which was dubbed the 'hardest puzzle in the world,' and this inspired the team to publish the book.


December 12

The killer was: puzzle 188, page 82

One of our colleagues, who is no longer with us, left the following clue to his killer:

SNLOU IAIRO SCSCN OLCIO IOIMM NVPAU OOORE CCCTN OISLP

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What killed him?


December 11

Seven words have been enciphered using a simple substitution. Decrypt them, and then put them in the appropriate order:



FRAFR CNEGL THRFF URNIRA RFGNGR YNQL PBYHZA

December 10

Wordbox: puzzle 156, page 71



A wordbox is a rectangle of letters in which a set of words can be read by starting at one letter and moving to an adjacent letter in a row or column, not diagonally, and not staying still. Retracing steps reusing letters is allowed. Thus a wordbox might be:



D O R F

I G E S

T A O T



Which contains DODO, DOG, FROG, STOAT, TIGER and TIT but doesn’t contain GOAT or GEESE. This wordbox is size 12 ie. 3 (rows) x 4 (columns)



What is the smallest wordbox which contains the names of all the seven dwarfs: BASHFUL, DOC, DOPEY, GRUMPY, HAPPY, SLEEPY, SNEEZY

December 9

Christmas movies: puzzle 143, page 67

(a) I A OEU IE

(b) IAE O I-OU EE

(c) OIA I

(d) EU O E I OE IA

(e) EO OOO

(f) E UE IA AO

(g) OE AUA

(h) E IAE EOE IA

(i) E OA

(j) IE A E A

(k) E OA EE

(l) E OU IE A

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December 8

A to Z: puzzle 140, page 66

For each letter, we haven't provided the full list but a selection of items, given in the correct order.

A DQ, KMKY, MMM

B IAS4U, O, INAGNYAW, ILR'N'R

C TBIB, YSS, DLTSGDOM

D OYH, TSOTC, LA(IBIL), DYWM

E SNA, IJDKWTDWM, THBTB

F F,FF,IWYS (P1&2)

G TBITB,G,DOTSOHS,YCCMA

H H, SOTSA,V-2S,TSLOA

I I,JG,GST,HDYS?

J P,LY,C,M

K NS,DI,NYT,M

L NWNC,CYBL,BS,RS,E

M ES,SBT,NEM,OWAM

N SLTS,IB,CAYA,L

O OPO,OPT,OH

P G&B,P,TTE,TIAL

Q TRM,IO,BB,LROM

R T,ER,HTAE,YS,TNK

S W,SYBT,2B1,WDYTYA

T WBSS,T,BI,BJ

U CWTAE,STCFTHOTS,SSOSFAGTIACAGWAP

V WIME,PJ,ETS,POT

W SBS,NYD,THBAO

X 2H,IMA,TO,AIS,W

Y YSMR(LAR),ITD,LCBTM

Z E,D,Z,W,Z,B-BC

December 7

Underground: puzzle 121, page 59

What follows? There are two stations missing at the end of this list:

MORDEN, MILE END, MOORGATE, MONUMENT, MAIDA VALE, MANOR HOUSE, MOOR PARK, MANSION HOUSE, MARYLEBONE, MILL HILL EAST, ?,?

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December 6

Complete the set: puzzle 67, page 41

5,8,9,12,?,20,23,25

December 5

Somewhere: puzzle 17, page 4

(a) What does UV stand for?

(b) Which Duke Ellington jazz standard has also been recorded by Annie Lennox and Nina Simone?

(c) Which boy band represented the UK in the 2011 Eurovision Song Contest?

(d) Which piece of music is believed to have been written by Henry VIII?

(e) In which US national park is Old Faithful?

(f) What do the bells of St Clements say?

(g) Which horse won the Grand National in 1973, 1974 and 1977?

What might you find at the end?

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December 4

Missing letter: puzzle 55, page 36



What is the missing letter?



?,?,?,?,n,?,?,?,?,?,?,u,u,i,n,i,o,?,u,n,i,i,i,?

December 3

Next pair: puzzle 31, page 27



What is the next pair of numbers in this series?

(18,19), (28,29), (38,39), (79,80), (81,82), (83,84), (85,86), (?,?)

December 2

Where next?: puzzle 6, page 2

What follows Vienna, Brussels, Prague, Copenhagen, Tallinn, Helsinki, Athens...

December 1

Christmas songs: puzzle 14, page 21

(a) O-LITOOFBEHOSTWESETHLI

(b) ECHEALITOUF-OLA-A-A-A-A-A-A-A-A-

(c) EYIDER--OW--RIEYIDER--AC--RT

(d) LEPHCHIRCK--HT

(e) LEEYLEEY----Y---

(f) TETETU--------NETE

(g) --MA----MA----------GI

(h) --N---IN----------

(i) ----L---------------LY

(j) --------------T-

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Each of the puzzles come from The GCHQ Puzzle Book, published by Penguin, which features more than 140 pages of challenges created by GCHQs code breakers

GCHQ Quizmas answers

The answers to the puzzles will be posted below in date order, 24 hours after the challenge is set.

December 12

Clue: Arranging the letters in a certain way will give you a disease that is a bit of a mouthful to say.

Answer: Pneumonoultramicroscopicsilicovolcanoconiosis

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Place the groups into a 9x5 grid and read up the columns from right to left.

S N L O U

I A I R O

S C S C N

O L C I O

I O I M M

N V P A U

O O O R E

C C C T N

O I S L P

December 11

Answer: SENSE PARTY GUESS HEAVEN ESTATE LADY COLUMN

Encryption has been done by moving each letter along 13 places. Put another way, the following cipher alphabet has been used:



Plain: ABCDEFGHIJKLMNOPQRSTUVWXYZ

Cipher: NOPQRSTUVWXYZABCDEFGHIJKLM



December 10

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Answer: The smallest (we could create) is of size 25:



ASHFG

BSLUR

HNEMD

AYEPO

PPZYC

December 9

Clue: Fans of Only Connect will recognise a pattern in this puzzle.

Answer:

(a) It’s a Wonderful Life

(b) Miracle on Thirty-Fourth Street

(c) Holiday Inn

(d) Dr Seuss’ How the Grinch Stole Christmas

(e) Beyond Tomorrow

(f) The Muppet Christmas Carol

(g) Love Actually

(h) The Nightmare Before Christmas

(i) The Snowman

(j) Jingle All The Way

(k) The Polar Express

(l) The Fourth Wise Man

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December 8

Clue: Each of the letters of the alphabet refer to a single word/item. The combination of letters that follow spell out phrases that are found on that particular item.

Answer:

Arrival (ABBA) Dancing Queen, Knowing Me Knowing You, Money Money Money

Britney (Britney Spears) I'm A Slave 4 U, Overprotected, I'm Not A Girl Not Yet A Woman, I Love Rock'N'Roll

Caribou (Elton John) The Bitch Is Back, You're So Static, Don't Let The Sun Go Down On Me

Dare (Human League) Open Your Heart, The Sound Of The Crowd, Love Action (I Believe In Love), Don't You Want Me

Elephant (The White Stripes) Seven Nation Army, I Just Don't Know What To Do With Myself, The Hardest Button to Button

Faith (George Michael) Faith, Father Figure, I Want Your Sex (P1&2)

Graceland (Paul Simon) The Boy In The Bubble, Graceland (or Gumboots), Diamonds On The Soles of Her Shoes, You Can Call Me Al

Heroes (David Bowie) Heroes, Son Of The Silent Age, V-2Schneider, The Secret Life of Arabia

Imagine (John Lennon) Imagine, Jealous Guy, Gimme Some Truth, How Do You Sleep?

Jollification (Lightning Seeds) Perfect, Lucky You, Change, Marvellous

Kick (INXS) New Sensation, Devil Inside, Need You Tonight, Mystify (or Mediate)

Legend (Bob Marley) No Woman No Cry, Could You Be Loved, Buffalo Soldier, Redemption Song, Exodus

Metallica (Metallica) Enter Sandman, Sad But True, Nothing Else Matter, Of Wolf And Man

Nevermind (Nirvana) Smells Like Teen Spirit, In Bloom, Come As You Are, Lithium

Ommadawn (Mike Oldfield) Ommadawn Part One, Ommadawn Part Two, On Horseback

Parklife (Blur) Girls & Boys, Parklife, To The End, This Is A Low

Quadrophenia (The Who) The Real Me, I'm One, Bell Boy, Love Reign O'er Me

Revolved (The Beatles) Taxman, Eleanor Rigby, Here There And Everywhere, Yellow Submarine, Tomorrow Never Knows

Spice (Spice Girls) Wannabe, Say You'll Be There, 2Become1, Who Do You Think You Are

Thriller (Michael Jackson) Wanna be Startin' Something, Thriller, Beat It, Billie Jean

Uummagumma (Pink Floyd) Careful With That Axe Eugene, Set The Controls, For The Heart Of The Sun, Several Species Of Small Furry Animals Gathered Together In A Cave And Grooving With A Pict

Violator (Depeche Mode) World In My Eyes, Personal Jesus, Enjoy The Silence, Policy of Truth

War (U2) Sunday Bloody Sunday, New Year's Day, Two Hearts Beat As One

X (Kylie Minogue) 2Hearts, In My Arms, The One, All I See, Wow

Youthquake (Dead or Alive) You Spin Me Round (Like A Record), In Too Deep, Lover Come Back To Me

Zoolook (Jean Michel-Jarre) Ethnicolor, Diva, Zoolook, Wooloomooloo, Zoolookologie, Blah-Blah Cafe

December 7

Clue: This puzzle is not as simple as it seems, and the order of stations is key.

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Answer: Marble Arch/19, Mornington Crescent/25. The stations are listed in order of Scrabble score, then alphabetically.

December 6

Clue: Another number-based puzzle that requires your knowledge of the alphabet.

Answer: 14. The number contains the letter at the corresponding position in the alphabet: Five, Eight, Nine, Twelve, Fourteen, Twenty, Twenty-three, Twenty-five

December 5

Clue: If you've answered the questions correctly, you'll notice a theme that will solve the puzzle.

Answer: A pot of gold.

(a) UltraVIOLET

(b) Moon INDIGO

(c) BLUE

(d) GREENsleeves

(e) YELLOWstone

(f) ORANGEs and lemons

(g) RED rum

What might you find at the end? The answers above point to the answer rainbow, and a pot of gold sits at the end of the rainbow in Irish mythology.

December 4

Clue: Think beyond the English alphabet.

Answer: The answer is ‘a’. Each of the letters is the last letter of the names of the letters of the Greek alphabet: alpha, beta, gamma, delta, epsilon, zeta, eta, theta, iota, kappa, lambda, mu, nu, ksi, omicron, pi, rho, sigma, tau, upsilon, phi, chi, psi, omega.

December 3

Clue: This may be a number-based puzzle but you’ll need to use word skills to solve it.

Answer: (97,98)

This pattern includes the next pair of consecutive numbers where the last letter of the first one is the same as the first letter of the last one. For example, ‘seventy nine’ ends in an ‘e’ and ‘eighty’ starts with an ‘e’.

December 2:

Clue: What makes these cities relevant in the country they are in?

Answer: Budapest. The European countries of which these clues are capital cities are in alphabetical order, for example: Vienna is the capital of A ustria, Brussels is B elgium and so on. Following suit, the next European country in the sequence needs to begin with an 'H' and if its Hungary then the capital is Budapest.

December 1

Clue: each line is made up of lyrics, rather than song titles, and only certain letters from these lyrics are shown. The key is to work out the pattern in which each of the letters are shown. And they are relative to the line they're on.

Answer: In the nth part, the nth and (n+1)th letters of each word are given.


For example, (a) is the first row so if n=1 the letters shown become 1 and 1+1, so 2; the first and second letters are shown.

In (b), n=2 so the letters are second and third of the words that are long enough to show both letters. This is why in (j), the 10th and 11th letters of each word should be shown but only 'triumphant' is long enough to accomodate this.

(a) O LIttle TOwn OF BEthlehem HOw STill WE SEe THee LIe

(b) dECk tHE hALls wITh bOUghs oF hOLly fA lA lA lA lA lA lA lA lA

(c) thEY saID thERe'd be snOW at chRIstmas thEY saID thERe'd be peACe on eaRTh

(d) whiLE shePHerds watCHed theIR floCKs by nigHT

(e) littLE donkEY littLE donkEY on the dustY road

(f) gaudeTE gaudeTE chrisTUs est natus ex maria virgiNE gaudTE

(g) o christMAs tree o christMAS tree thy leaves are so unchanGIng

(h) a spacemaN came travellINg on his ship from afar

(i) hey mr churchilL comes over here to say we're doing splendidLY

(j) o come all ye faithful joyful and triumphanT