# A cipher sequence

For this task you will be asked to solve a cipher... or should I say, cipher-S! You see there are many layers to this puzzle...

He who answers correctly first with the name of a famous cipher, shall receive points in the form of online reputation and proceed to their final task - enjoying their sense of accomplishment...

Good luck...

QWXNFTGBCJJOLRTRJMKNHQAASVJMKJDDF11GQRNNUEOE14ICPDVBYBPFCJIZBYGERUQGOAGOHMDJLPVWPFTXJCCKWUILUQOCUOPP?RUBEUY1LRTJHUGPVU2035TUNTQGBSLUMVGXDSVLNTRSHIEIRBHKSDUHSWNULNPWVBQKYYQWXEIGVINRSEXPUQMUYWLDXBOOAWWZJEPXZRBEDHVS

Oh, and here is the information about the other candidates:

Not that that would be of any help at all of course... (or is it?)(or isn't it?)(or is it?)(or isn't it?)...

Community wiki

CAESAR

Layer 1 (solved by noedne):

The job titles first letter say 'NAMES CLUE', so there is something in the names...

Taking the first letters of the first names, the middle letters of the middle names and the last letters of the last names we get the phrase:

'GRONSFELD KEY IS DAYS OF DOBS'

Decrypting using a Gronsfeld cipher with the key 381612292411722 (the days of the DOBs) and adding some spaces gives:

NOW HERES A FINE PROBLEM FOR YOU IF I HAVE 11 APPLES AND 14 BANANAS AND THEY ARE COMPANY EFFICIENT THEN WHAT IS THE SOLUTION? PLZATX1EPRGZTAOTS2035KSJSPZZQIMLPFVBJTHMSKQFFWHLAFIJBQGRPLSIFOQUZOBWUPVQCGDNHHQQCONQPLNWUIVWVNMYNUVIDIVXOTDXGTQ

Layer 2 (solved by cpcodes):

This is an affine cipher ('a fine problem') and the coefficients ('company efficient') are a = 11 ('11 apples') and b = 14 ('14 bananas'). Applying this decrpyts to:

TV BURP 1ST FEBRUARY 2035 CYJYTBBMQOVTLDNJRXOYCMLLWXVULQJNMEFTVYQLAMKBANWKTDMGEZHXXMMGAHMTVHWKQDWDHOIHKDQZQDPARZPERM

Layer 3 (solved by Einb):

This is a Hill cipher (Harry Hill's TV Burp) - and the date simplifies to 1/2/35 which is the matrix needed. This gives

MIDDLE TRAILS DEFENCES OUTWORN RDRHOAGNWVNULYOEDANOEPCEEENLYNFEEOTERNEOEETALTHARIBWXETDTRALPRN

Layer 4 (solved by Reinier):

Taking the middle sections of TRAILS, DEFENCES and OUTWORN give RAIL FENCE TWO - decrypting gives:

RED OR THE ORANGE NOW EVENTUALLY TO HEAD RAINBOW EXPECTED ETERNALLY PNRFNE

Layer 5 (solved by Reinier):

The first letters say ROT ONE THREE and decrypting PNRFNE with ROT13 gives the final answer CAESAR.

One layer:

Taking the first, middle, and last letters of the first, middle, and last names gives

GRONSFELD KEY IS DAYS OF THE DOBS

Decrypting the ciphertext using the Gronsfeld cipher with the key 381612292411722 (the days of the DOBs) and adding some spaces gives

NOW HERES A FINE PROBLEM FOR YOU IF I HAVE 11 APPLES AND 14 BANANAS AND THEY ARE COMPANY EFFICIENT THEN WHAT IS THE SOLUTION? PLZATX1EPRGZTAOTS2035KSJSPZZQIMLPFVBJTHMSKQFFWHLAFIJBQGRPLSIFOQUZOBWUPVQCGDNHHQQCONQPLNWUIVWVNMYNUVIDIVXOTDXGTQ

• Just a note as well, you have done surprisingly well in finding the names message and I added another clue to find that in the table, but I guess you didn't need that :) Commented Apr 27, 2018 at 19:06
• Ugggh, 2035 needs to be 1 left as well. So sorry. Me encoder got rid of numbers, and I miscounted 1 too many. Commented Apr 27, 2018 at 19:18
• How do you get the key? I don't understand.
– Sid
Commented Apr 27, 2018 at 19:37
• @Sid Does the edit clarify? Commented Apr 27, 2018 at 19:39
• @Noedne yep, it does. Sorry, I was just stupid. :/
– Sid
Commented Apr 27, 2018 at 19:42

Layer 2 (partial):

Taking the Gronsfeld decoded second half, and running it through the Affine cipher with A (for Apple) set to 11 and B (for Banana) set to 14

results in

TVBURP1STFEBRUARY2035CYJYTBBMQOVTLDNJRXOYCMLLWXVULQJNMEFTVYQLAMKBANWKTDMGEZHXXMMGAHMTVHWKQDWDHOIHKDQZQDPARZPERM

So

The date 1st February 2035 (CY?) is clearly legible, but the rest seems like gibberish (though TV Burp has some humor value)

I leave it here for someone else to carry forward, though I'll keep plugging at it.

• Yep that’s the second layer. Maybe you think about the full title of The TV Burp programme, might point you towards the next cipher type... Commented Apr 28, 2018 at 7:44

Another layer possibly?

From cpcodes' answer and Beastly Gerbil's comment on it , I think that

The next step is using a Hill Cipher, from the full title Harry Hill's TV Burp. The matrix key is the date that cpcodes found in their answer: 1st February 2035 -> {2, 1, 3, 5}

Applying this to the remainder of the message yields

MIDDLETRAILSDEFENCESOUTWORNRDRHOAGNWVNULYOEDANOEPCEEENLYNFEEOTERNEOEETALTHARIBWXETDTRALPRN

Hopefully this parses into

The clue for the next type of cipher being "MIDDLE TRAILS DEFENCES OUTWORN" with the message to decrypt being the remainder, "RDRHOAGNWVNULYOEDANOEPCEEENLYNFEEOTERNEOEETALTHARIBWXETDTRALPRN"

(That 5 min later edit)->

I see "RAIL" and "FENCE" which might point to using a Rail-fence cipher.

To which I leave to another Puzzler :^)

• Well done! That was quite possibly the hardest layer. You have the right idea with the next layer too... think about the rail and fence positions within the words and see if you can get the next layer as well, you are nearly there Commented Apr 28, 2018 at 12:32

CAESAR

Layer 4:

If we take the middle letters of TRAILS, DEFENCES and OUTWORN (found by Einb), we get RAIL, FENCE and TWO, so applying the rail-fence cypher with two rails to the remaining text gives
RED OR THE ORANGE NOW EVENTUALLY TO HEAD RAINBOW EXPECTED ETERNALLY PNRFNE

Layer 5:

Now taking the first letters of each of the words gives ROTONETHREE, and using ROT13 on PNRFNE gives CAESAR.

• Well done! You've found the final answer :) Commented Apr 28, 2018 at 12:34
• Nice! I didn't think of looking to split within the words themselves
– Einb
Commented Apr 28, 2018 at 12:38