# A very short story, with letter swaps

Part of the community metapuzzle.

I wrote a very short story. To make it harder to read, I made some letter swaps throughout.

Omce apom o rine, b cbspemres nbdk n pkwmar marrks aod nicelk gaodpich lus fwocp, twr pie fdfurfc gfnnko enk kn.

Hykcy yusd co nhoa anuse hpt ifcmth g rcobf swbmfc monnfc thgc iovf?

• Well, it appears to start with "Once upon a time, a..." can't really read beyond that though – dcfyj Nov 21 '16 at 19:08
• ...a carpenter made a peanut butter... – Matsmath Nov 21 '16 at 19:12
• I hope there is at least an algorithm that determines what letters are swapped... Otherwise I wouldn't even call this a cipher, honestly. – user14478 Nov 21 '16 at 19:16
• @LukasRotter obviously not with once and a, as it would start with amce instead – Beastly Gerbil Nov 21 '16 at 19:16
• I don't think this deserves to be at -4, which is where it currently sits. It's hard to be sure before the solution is complete, but it already looks to me more satisfying than it did at first glance and I suspect it will be further redeemed as it gets finished. – Gareth McCaughan Nov 21 '16 at 21:46

Idiotic, which has length 7>5 and 7 is a prime number

The text is:

Once upon a time, a carpenter made a peanut butter and pickle sandwich for lunch, but his idiotic kitten ate it.
Which word in this story has length a prime number bigger than five?

Changing key with translation:

|ABCDEFGHIJKLMNOPQRSTUVWXYZ|
|abcdefghijklmnopqrstuvwxyz|

O

|ABCDEFGHIJKL M N OPQRSTUVWXYZ|
|abcdefghijkl>n<>m<opqrstuvwxyz|

Once

| A BCDEFGHIJKLMNOPQRST U VWXYZ|
|>u<bcdefghijklnmopqrst>a<vwxyz|

Once upon

|ABCDEFGHIJKLMN O PQRST U VWXYZ|
|ubcdefghijklnm>a<pqrst>o<vwxyz|

Once upon a

|ABCDEFGHIJKLMNOPQ R S T UVWXYZ|
|ubcdefghijklnmapq>t<s>r<ovwxyz|

Once upon a time,

|A B CDEFGHIJKLMN O PQRSTUVWXYZ|
|u>a<cdefghijklnm>b<pqtsrovwxyz|

Once upon a time, a ca

|ABCDEFGHIJKLMNOPQR S T UVWXYZ|
|uacdefghijklnmbpqt>r<>s<ovwxyz|

Once upon a time, a carpenter mad

|ABCD E FGHIJ K LMNOPQRSTUVWXYZ|
|uacd>k<fghij>e<lnmbpqtrsovwxyz|

Once upon a time, a carpenter made

|A B CDEFGHIJKLMN O PQRSTUVWXYZ|
|u>m<cdkfghijelna>b<pqtrsovwxyz|

Once upon a time, a carpenter made a pe

|ABCDEFGHIJKLM N OPQRSTUV W XYZ|
|umcdkfghijeln>w<bpqtrsov>a<xyz|

Once upon a time, a carpenter made a peanut

|ABCDEFGHIJKL M N O PQRSTUVWXYZ|
|umcdkfghijel>b<w>n<pqtrsovaxyz|

Once upon a time, a carpenter made a peanut butter and

|ABCDEFGHIJKLM N O P QRSTUVWXYZ|
|umcdkfghijelb>p<n>w<qtrsovaxyz|

Once upon a time, a carpenter made a peanut butter and pickle

|ABCDEF G HIJKLMNOPQRS T UVWXYZ|
|umcdkf>s<hijelbpnwqtr>g<ovaxyz|

Once upon a time, a carpenter made a peanut butter and pickle s

| A BCDEFGHIJKLMNOPQRSTUV W XYZ|
|>a<mcdkfshijelbpnwqtrgov>u<xyz|

Once upon a time, a carpenter made a peanut butter and pickle sandwich

|ABCDE F GHIJK L MNOPQRSTUVWXYZ|
|amcdk>l<shije>f<bpnwqtrgovuxyz|

Once upon a time, a carpenter made a peanut butter and pickle sandwich for lunc

|ABCDEFG H IJKLMNO P QRSTUVWXYZ|
|amcdkls>w<ijefbpn>h<qtrgovuxyz|

Once upon a time, a carpenter made a peanut butter and pickle sandwich for lunch,

|ABCDEFGHIJKL M NOPQRS T UVWXYZ|
|amcdklswijef>g<pnhqtr>b<ovuxyz|

Once upon a time, a carpenter made a peanut butter and pickle sandwich for lunch, but hi

|ABCD E F G HIJKLMNOPQRSTUVWXYZ|
|amcd>s<l>k<wijefgpnhqtrbovuxyz|

Once upon a time, a carpenter made a peanut butter and pickle sandwich for lunch, but his

|ABCDE F GH I JKLMNOPQRSTUVWXYZ|
|amcds>i<kw>l<jefgpnhqtrbovuxyz|

Once upon a time, a carpenter made a peanut butter and pickle sandwich for lunch, but his idiotic ki

|ABCDEFGHIJKLM N OPQ R STUVWXYZ|
|amcdsikwljefg>t<nhq>p<rbovuxyz|

Once upon a time, a carpenter made a peanut butter and pickle sandwich for lunch, but his idiotic kitten

| A BCD E FGHIJKLMNOPQRSTUVWXYZ|
|>s<mcd>a<ikwljefgtnhqprbovuxyz|

Once upon a time, a carpenter made a peanut butter and pickle sandwich for lunch, but his idiotic kitten ate

|ABCDE F GHIJ K LMNOPQRSTUVWXYZ|
|smcda>e<kwlj>i<fgtnhqprbovuxyz|

Once upon a time, a carpenter made a peanut butter and pickle sandwich for lunch, but his idiotic kitten ate it.
W

|ABCDEFGHIJKLMNO P QRSTUVWX Y Z|
|smcdaekwljifgtn>y<qprbovux>h<z|

Once upon a time, a carpenter made a peanut butter and pickle sandwich for lunch, but his idiotic kitten ate it.
Which

|ABCDEFG H IJKLMNOPQRSTUVWX Y Z|
|smcdaek>h<ljifgtnyqprbovux>w<z|

Once upon a time, a carpenter made a peanut butter and pickle sandwich for lunch, but his idiotic kitten ate it.
Which word

|AB C DEFGHIJ K LMNOPQRSTUVWXYZ|
|sm>i<daekhlj>c<fgtnyqprbovuxwz|

Once upon a time, a carpenter made a peanut butter and pickle sandwich for lunch, but his idiotic kitten ate it.
Which word in th

|AB C DEFGHIJKLMN O PQRSTUVWXYZ|
|sm>n<daekhljcfgt>i<yqprbovuxwz|

Once upon a time, a carpenter made a peanut butter and pickle sandwich for lunch, but his idiotic kitten ate it.
Which word in this

| A BCDEFGHIJKLMNOP Q RSTUVWXYZ|
|>q<mndaekhljcfgtiy>s<prbovuxwz|

Once upon a time, a carpenter made a peanut butter and pickle sandwich for lunch, but his idiotic kitten ate it.
Which word in this stor

|ABCD E FGHIJKLMNO P QRSTUVWXYZ|
|qmnd>y<ekhljcfgti>a<sprbovuxwz|

Once upon a time, a carpenter made a peanut butter and pickle sandwich for lunch, but his idiotic kitten ate it.
Which word in this story ha

|ABCDEFGHIJKLMNOP Q RS T UVWXYZ|
|qmndyekhljcfgtia>b<pr>s<ovuxwz|

Once upon a time, a carpenter made a peanut butter and pickle sandwich for lunch, but his idiotic kitten ate it.
Which word in this story has leng

|ABCDEFGHIJKLM N OPQRS T UVWXYZ|
|qmndyekhljcfg>s<iabpr>t<ovuxwz|

Once upon a time, a carpenter made a peanut butter and pickle sandwich for lunch, but his idiotic kitten ate it.
Which word in this story has length

|ABCDEF G HIJKLMNO P QRSTUVWXYZ|
|qmndye>a<hljcfgsi>k<bprtovuxwz|

Once upon a time, a carpenter made a peanut butter and pickle sandwich for lunch, but his idiotic kitten ate it.
Which word in this story has length a p

|AB C DEFGHIJKLMNOPQR S TUVWXYZ|
|qm>r<dyeahljcfgsikbp>n<tovuxwz|

Once upon a time, a carpenter made a peanut butter and pickle sandwich for lunch, but his idiotic kitten ate it.
Which word in this story has length a prime num

|ABCDEFGHIJKL M NOP Q RSTUVWXYZ|
|qmrdyeahljcf>b<sik>g<pntovuxwz|

Once upon a time, a carpenter made a peanut butter and pickle sandwich for lunch, but his idiotic kitten ate it.
Which word in this story has length a prime number bi

|ABCDEFGHIJKLM N OP Q RSTUVWXYZ|
|qmrdyeahljcfb>g<ik>s<pntovuxwz|

Once upon a time, a carpenter made a peanut butter and pickle sandwich for lunch, but his idiotic kitten ate it.
Which word in this story has length a prime number bigger tha

|AB C DEFGHIJKLMNOPQR S TUVWXYZ|
|qm>n<dyeahljcfbgiksp>r<tovuxwz|

Once upon a time, a carpenter made a peanut butter and pickle sandwich for lunch, but his idiotic kitten ate it.
Which word in this story has length a prime number bigger than

|ABCDEFGH I JK L MNOPQRSTUVWXYZ|
|qmndyeah>f<jc>l<bgiksprtovuxwz|

Once upon a time, a carpenter made a peanut butter and pickle sandwich for lunch, but his idiotic kitten ate it.
Which word in this story has length a prime number bigger than five?

• This is very nice. What's the obstacle to completing it? :-) – Gareth McCaughan Nov 21 '16 at 21:24
• (I think it continues: "kitten ate it. Which word in this story has", though I'm not certain about the last word.) – Gareth McCaughan Nov 21 '16 at 21:33
• ... Hmm. After that the next ciphertext word is "ifcmth" whose first three letters all corresponded to plaintext "i" when they were most recently seen :-) and it's not easy to guess what happens next just by looking at the remainder of the ciphertext as decrypted using the cipher-so-far. Perhaps there's some pattern to the substitutions being introduced? – Gareth McCaughan Nov 21 '16 at 21:44
• Sorry for the FGITW but I just solved it and wanted to post the answer. – boboquack Nov 21 '16 at 22:10
• @GarethMcCaughan I had problems working out whether kipper was going to be a red herring as it so often is. – boboquack Nov 21 '16 at 22:11

There's probably more to it, but looks like the cipher is a motley of various schemes like:

- no substitution
- nearby letters in the alphabetic order
- nearby letters on the keyboard
- vowels replaced by other vowels

... but others cannot be explained, so it might be some kind of position-dependent cipher ...

But using the above schemes and some lots of guesswork, it kinda looks like:

Once upon a time, a carpenter made a peanut butter and ... sandwich for lunch, but ... ... settle for it.

Which word in this quote has ... a prime number (letter?) used once?

• I was working similarly. I got "...peanut butter and pickle sandwich for lunch, but his idiotic kitten ate it." (not sure if that's right). – GentlePurpleRain Nov 21 '16 at 20:55
• Some substitutions are pretty consistent, like T $\rightarrow$ R, R $\rightarrow$ S, E $\rightarrow$ K. Others are much more "fluid". – GentlePurpleRain Nov 21 '16 at 20:59
• Assuming "prime number letter" refers to a letter whose numerical representation is prime, that would mean {b, c, e, g, k, m, q, s, w}. There are 3 words that I could find that fit this description: but, idiotic, and ate. – GentlePurpleRain Nov 21 '16 at 21:15

So far I have

Once upon a time, a carpenter made a peanut butter and pickle sandwich for lunch, but his idiotic kitten ate it. Which word in this story has ??? (last bit got by @GarethMcCaughan and @boboquack)

Can't see a pattern of how to decode it.

• I'm pretty this isn't so much a cipher as much as it's just taking the letters given and swapping them to rebuild the words. – dcfyj Nov 21 '16 at 20:43