Puzzle: "No Laughing Matter"

The Game Room
1

A loud knocking at your door disturbs the peace on a hot but pleasant summer afternoon. You answer and find Agent Jones of the CIA at your door. Uh oh. Agent Jones rarely visits unless he has a difficult code to crack. And whenever the CIA can’t decipher a secret message, they turn to You, the greatest cryptologist in the land.

You exchange greetings with Jones and fetch your friend a cup of the finest organic Guatemalan coffee. Jones has a worried look on his face as he settles into an easy chair, opens his notepad, and begins his story.

Jones reports that enemy spies have been quiet for a long time. Too quiet. The CIA had begun to suspect that trouble was in the works and had several of their top men on the case, including Agent Jackson, a rugged, intelligent and reliable man. Last week Jackson radioed to Jones that he had discovered a secret coded message being handled by an unexpected source. But before Jackson could go into detail, the call disconnected, and Jones heard nothing more for several days.

Then yesterday, the CIA received a call from the Pentagon. Agent Jackson had been found in their parking lot. He’d been brutally attacked. Jackson gasped his last breaths lying in a puddle of blood between two oversized SUVs. He had a letter-opener savagely jabbed through his chest. An unidentified assailant was seen running from the scene, but was unfortunately not captured.

“That’s terrible.” You say. You had met Jackson at last year’s CIA Easter egg hunt. He had a wife and two kids.

“Do you have any clues?” You ask, anger seeping into your voice.

Jones nods and continues:

Jackson was dying when he was found. He croaked these final words before expiring:

“I tried to decode the message…but those damn spies were after me. I tried…but there were just too many of them. Get this coded message to Jones at the CIA. He’ll know what to do…We are in trouble because there’s a… a…mo--------“

Jones closes his notebook and frowns.

“Jackson had a mysterious note crumpled in his hand when he died.” Agent Jones grimly hands you a blood-stained wrinkled piece of paper. “This is the original. All our experts and computers have come up with nothing. So we turn to You.”

You promise to do your best. But can you solve the code and discover the spies latest nefarious scheme in time to prevent further disaster?

++++++
Y2AO2 CXN RFLO U6MB2NM S21CC6OXRLN N4Y2AAT2:

RAAS AAML2N36H 6LZCLNM 2U2KF2SMY MJEER ER1 RLAO NQBBX2N JXUCCU NSE26V 6JB6H A1ORT 6E ZLFX323 MBBRLO RA1 MCCY2 C Q2SMF6ZRS 6SB3 NDUXQ XSMEER A6 NLFFQQUH 4UARN2M. MYDD2O2 MYB2H JXUUE 1XES3 5XBBR-Y6G6O3 NLAXMN QUC6SM23 D5H RLOE CCTRU2. J26BOXSZ MYA2N2, 5ARMY TC2S 46EES 2SEEM2O MAY2 Q2SM6ZRS’NE N24OA2M U65RBO6MROH 6SC3 NEM26U 6A N6TQFU2 C R1F 326EE3UH YHC2S6 1FUL. BWLNM Y6K2A E6 46AO J6EXMXSZ RLMANX32 C1RO MEY2 PLAX4V ZE2M6J6H. MCCY2 JAROU3 JFFXUU 52A E6M RFLO BBT2O4H!

++++++

2

No. We’re fucked.

3

Please give the pronunciation of Agent Jackson’s final uttered syllable.

I do hope that Agent Jones isn’t a mole.

4

Witness reports vary on the “mo-” pronunciation. Two witnesses, both policemen, swear its a hard “o” as in the suggested possibility. A couple of other witnesses (a CIA employee and a passing street mime) heard an “ah” sound as in “mobster”. And finally one other witness, a Swedish tourist, thinks it was an “oo” sound, as in “moon”. At least they all agree on an “o”.

Fortunately you know and trust your friend Agent Jones completely. You vow to perservere and put thoughts such as “We’ re f*****D” out of your head.

5

This story gets more implausible all the time.

[spoiler]Sure. A Swedish tourist (and a passing street mime? :dubious:) is being allowed to roam the parking lot at the Pentagon. They can’t even roam the parking lots at the USPS mail processing facility I work at.

Jones is a mole.[/spoiler]

6

In retrospect, it was probably not the best idea to hold “Meet The Family Day” for Pentagon employees and staff out in the parking lot. But as part of our new open government, the idea was to give the staff a morale boost and improve the Pentagon’s overall public image. PR people seem to feel the public perception of the Pentagon is that it is a sinister cold forbidding place. They thought a picnic atmosphere might improve this. A murder during the festivities did not help matters, I can tell you.

The area was sealed off immediately and all mimes, tourists, face-painters, clowns, pretzel salesmen, and the like were questioned searched and released. Indeed, it is hard to understand how the murderer escaped as everyone did have to go through security to enter and leave…

7

Jones is back at your door with more very bad news. Early this morning there was a break-in at a top secret biological lab in the Pentagon. A dangerous virus has been stolen!

“A virus…??” A chill runs down your spine.

“Yes.” sighs Jones. “The hyena flu virus is one of the most dangerous of animal viruses because it spreads so easily to humans. Any human who is sneezed on by an infected hyena is bound to get the virus, and then it mutates and theoretically transfers easily from human to human. People who catch it display all the classic signs of flu. Additionally, the infected laugh uncontrollably. It is almost always the excess laughter that finally kills. All samples worldwide have been destroyed except the one in the secret Pentagon lab. And now that is gone. We believe it is in the hands of the spies.”

You look for signs that Jones is joking. But one look in his eyes tells you this remarkable story is true.

“This morning there was a tour of the Pentagon that started at 8am. We can tell from the cameras that two individuals walked away from the group and entered a closet. They emerged wearing protective gear. You’ve probably seen what those hazardous material suits look like on TV. Like beekeepers going to war. No one can tell who is inside them. I can’t believe that our security lapsed so badly, but this must have been an inside job. The two were able to sneak into the lab and steal the vial of virus. Indeed, the guards there are so used to seeing scientists in haz-mat suits that they paid no notice. The spies had all our security codes for access. The duo escaped by returning to the closet, redressing, and joining the next tour group.”

You suspect a lot of people are going to get fired over this fiasco.

“We talked with Janice Sullivan. She is the tour guide who was on duty this morning. She says the two men acted normally, and she was so busy answering touristy questions that she lost count of how many people were in her group. We suspect several other tour members were also spies whose goal was to distract anyone from noticing the heist. Indeed, one tourist, a Mr. Jeff Smith, became ill during the first group tour and that kept everyone’s attention away from the actual number of people there.”

“Have you nothing to go on?” You inquire.

“We are interrogating Mr. Smith, but he so far claims no knowledge of the crimes. As you know, we can no longer use any torture techniques, but we are speaking to him in a very harsh tone.”

You are stunned how such events could be occurring inside what you had believed to be the most secure building in the world.

“There’s also this.” Jones produces a folded piece of paper. “This coded message was found on the floor of the supply closet. We think it was dropped by one of the spies when he changed clothing.” He hands another enigmatic coded message over to you.

What now?

+++++++

6PGYT1 NZEE3 ZFI3T7 2VAM LY7AV 675AW NES SAMP O35P3DDN Z3C74QM7PN3PO AYTOY43 NCZ3 57NE75SU6O SAA2 C VMAAP7I 57L3PTGGO YGGT LYPB1YTY7. SET K34ET3O47I TY1GZN ISFM KYVCV 6P3A7W YTENS NZDD3 AT7NYST7V HESS 7TD4 BBON37V NZP3C3 ZI3DDT7O. REMN NZF3 ZI3AT7O YGT 57B13O 7TEE4 NP7TOBBRSPN NAZ3U ZCC3P3. FK3 KYVGV YT2E35N NCZ3 7TYUA7VO KYENZ CC2VM 7T4E OF3N NZ3GU VSSGGO3 SAT NBZ3 RSRAMV7NYST MTGGV3OO SEMP 43U7FT4O 7BP3 D UC3N. 5STEN75N XA7T YF2 ISEM ZF7L3 7GTI QM3ONYSFFTO.

+++++++

8

Jones’ agents might want to talk harshly to the tour guide “Jan” as well. After that they might need a break; maybe they should go sightseeing here on Wednesday, followed by an evening trip to the zoo to see the hyenas.

I’m not sure I’ve completely solved the cipher, though. The doubled letters may have some significance I’m missing.

9

Congratulations Omphaloskeptic!

Once again You have saved the world!

Acting on your tip, the CIA just raided a house in rural Luray, Virginia. It’s owner is listed as “Janice Sullivan”. A quick search led to an underground passageway and a previously unknown cavern now configured into a modern spy headquarters. Those working inside were apprehended, including two men who were identified as the individuals seen on the camera at the Pentagon this morning.

A thorough search of the cave found no vial of hyena influenza virus. However, that vial was later discovered upstairs in the Sullivan refrigerator. It had been concealed in a small Tupperware container next to the potato salad.

10

What’s really strange is that, on one of my shorter flights this Saturday, the guy seated next to me was reading text on his iPhone that looked very similar to this (had more Hs and no numbers) as if he were reading English. Guy was American, but on a flight from Frankfurt to Amsterdam. We didn’t speak, but I could gather he was American when he ordered his beverage. I didn’t exactly stare at his screen, but it was obvious he was reading some kind of code. He wasn’t working it out anywhere, just reading it.

I wonder who he worked for.

11

Okay, spill.

12

It is a pleasant Wednesday evening as Jones and You sit quietly in your abode sipping steaming hot Sumatran coffee. As is always the case after a tough code is cracked, the adrenalin rush has tempered and the mood is festive.

“I mulled over this code for a long time and got nowhere,” admits Jones. “And yet You solved it in less than 24 hours. How did you do it? Okay, spill.”

Smiling, You turn to Jones. “All right…but first, give me the latest news on Janice Sullivan. Did you catch her? And how did she get all that access? You can’t tell me a Pentagon tour guide can so easily get her hands on such top secrets.”

Jones sets down his cup. “Unfortunately, Ms Sullivan is still at large. Hopefully we will snare her before she cooks up another spy scheme.”

Agent Jones gives you more shocking details. Jan Sullivan was not only a tour guide, she was also the mistress of several top people at the Pentagon…people who really should have known better. Through various tricks and pillow talk, the admittedly very lovely Ms. Sullivan wormed the secret details out of unsuspecting generals and scientists.

Ms. Sullivan was also the Pentagon employee who misidentified the “Mo-” sound, causing confusion. Indeed “Mole” was likely the word poor Agent Jackson was trying to spit out as he died.

It is also suspected that the evil Ms. Sullivan poisoned the snack of the poor ill tourist, Mr. Smith. He has been exonerated.

“That’s about all. Without You we wouldn’t be sitting here so peacefully. And there would have been another crime tonight at the zoo. So tell me, how’d You do it?”

You put your feet up on your favorite footstool and begin.

“Take a look at the first code. What do you notice first? I would guess the presence of those mysterious numbers. And then as you try to decipher, you encounter letter substitution impossibilities. After all, few words begin with double letters, right. It’s not the aardvark flu, after all.”

“Right!” exclaims Jones. “So if I can’t do letter substitutions, what else is there to go on?”

“Notice something else as well. Something that Agent Jackson tried to tell us in his dying words. When he said there were ‘too many of them’ he couldn’t have been talking about spies. After all, only one was seen running away from the crime. We now know that was Jan Sullivan, who doubled back and pretended to be a witness. Too many of what then? Well, look at the code. Every letter of the alphabet shows up in that first coded message…and 6 numbers besides. That’s too many.”

Jones shakes his head and takes another sip of coffee. “All right. So there are too many characters in the code. What does that mean?”

You take a moment to refill your cup and continue:

“Now how do you solve a traditional cryptogram? You hunt for simple words like ‘a’ or ‘the’ or ‘that’. There are many common words that appear in texts that the trained decipherist looks out for. You also look for letter frequency, to help you spot the most used letters such as ‘E’, ‘A’, and ‘T’. So with all this in mind, I tried to solve the first code… but still came up with nothing.”

You set your cup down and pause for effect.

“But then came the second code. Now appeared the number ‘7’, and what looked to be a very different set of substitutions. Ah, but there was one more vital piece of information. A crime had been committed. And if this code was related to the crime (and I suspected that it was) could I not expect certain other words to possibly be in the message… longer words that might give away the code and its secret?”

You once again pause to sip.

(and perhaps we’ll let Omphaloskeptic explain how the riddle was solved from here.}

Are you there Omphaloskeptic?

13

My solution method was pretty straightforward (spoilered in pieces for partial solutions). Frequency counts:[spoiler]Because the word and sentence lengths seemed reasonable as punctuated, I guessed that only the letters and numbers were changed. The monograph letter and number frequencies



     1  2  3  4  5  6  A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Zf
 75  8 42 12  7  5 32 24 15 19  4 23 12  1 10  0  9  2 16 30 21 19  1  8 24 19  6 19  2  1 17 14  7

     2  6  M  R  A  E  N  U  S  O  C  X  L  B  Y  F  3  H  J  Q  1  Z  4  T  5  D  V  K  W  P  G  I
 75 42 32 30 24 24 23 21 19 19 19 19 17 16 15 14 12 12 10  9  8  8  7  7  6  5  4  2  2  1  1  1  0

(these are for the first code) were very nonuniform, suggesting some variant of a single-substitution cryptogram. The space character is most frequent, suggesting that it also remains unchanged.

The digraph frequencies show an especially interesting pattern.


      1 2 3 4 5 6 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
    . 210 7     3 3   2   4 1   8       1 6 4 7   1 2 4 1 3 2     2 2
1   2 . 1         2   1                             2
2   2   . 3   1   2 2 2 1 2 1       1 1 1 3 3 2   2   1 2 3     1 6
3   1   2 .         1 1   1                 1 1       1   1     2
4   3   1   .                               1 1                 1
5   3         . 1       1
6   6   4 1 2   . 1 1 2   2 1 1     2     2 1 1       1   2       2
A   3   4     1 2 3                 1   3 2   1     2     1       1
B   2           1   4               1     2       1 1 1         1 1
C   5 1               5         1         2           1 1 2         1
D   1                   1                   1                     1
E   3           4         5         1     2 2 1       2   1     1   1
F     2                     2       1 1 2 1       1 2
G               1             .
H       1   1 1 3               .             1           2       1
I                                 .
J   6           2                   .     1
K       1       1                     .
L               1     1     2           . 1 2   1   5     1   1     1
M   9   3       3 1       2             1 . 3       1 5         2
N   9   4         1                     3 1 .       1 1         1
O     1 3   1   2 3 2                   4     .     3
P   1                                           .
Q   3                       1               1     1     1       1
R   7 1 1     1   3 2     3               1   1     .   1       1   2
S   1   6       3 1       2                 1       2 .         3
T   1           1 1 1 1                             1   .
U   2   1 1 1   1     1 1   2                 1   2 1     2     3
V           1   1                                           .
W                   1                                         .
X   1 1       1   2 1 1   1 2       2     1 1 2           1     .
Y   2       1     1   2   1               5         1             .
Z   2           2                       1             2             .

Along the diagonal (marked with dots), doublets AA BB CC DD EE FF all occur quite frequently; otherwise, doublets are pretty rare (two doubled UU and one QQ), more like English doublets. Interestingly, there are six of these frequent doublets, and the code involves six numerals. This pattern continues to the second code, which has doublets AA-GG and numerals 1-7. So these letters, or at least their doublets, are probably somehow special. Luckily for me, I decided to ignore these letters for now; at this point I thought they probably indicated a code shift of some sort.[/spoiler]Base cipher map: Looking back at the frequency-sorted monographs, the most common characters (after the space) are 2 and 6, while for the second code the most common are 3 and 7: In each case the most common characters are two digits, four apart. This suggested A and E to me; 2 was a more common word ending than 6, so I identified 6->A and 2->E, and so obviously 5->B, 4->C, 3->D, 1->F. Perhaps I should have continued in this vein, but with just these identifications it is easy to solve the rest of the puzzle as a standard cryptogram. I solved a few of the segments between the marked doublets (both discuss hyenas and flu, as it happens) and discovered that they all seemed to use the same cipher; it turns out to just be an alphabet reversal, continuing the pattern from the numerals. The resulting plaintexts explain the nefarious plan described by Jones.Extra letters (with solution to the first base cipher): [spoiler]What’s left is the extra letters, which in these messages have just been ignored entirely; my original idea, that they might mark a cipher shift or key change, wasn’t right. This is potentially a lot of extra information. For example, the first cipher decodes to

The numbers 123456 mark the positions of letters FEDCBA in the cipher. There could be another cipher hidden in these numbers, but I haven’t found anything that seems to decode nicely.[/spoiler]

14

The spies never had a chance with You on the side of Good!
Just hope Jan Sullivan realizes it and turns herself in…