I explored a "many nulls" hypothesis for the 340 excluding periodical transposition using the newly developed nulls and skips solver. Such that Zodiac may have added many nulls while applying the homophonic substitution layer. A null is an added symbol or letter that is not make-up of the plain or cipher text.
1) Determine a realistic upper-bound for the amount of nulls that can be solved. (51 nulls or 15% of the cipher text)
2) Try it on the 340. (tried up to 15%, no solve)
The 408 (capped to 340 length) will be used to determine a upper-bound for the amount of nulls the solver and n-grams can handle.
With 17 added nulls the 408 still solves without using the nulls and skips solver:
ILIKEKILLINGPEOPL EBECAUSEITISSOEMU CHFUNAITINAMOREFU NKTHANKHILLINGWIL DGAMEINTHEFORREST BECAUSEMANISTHEMO ATDAANGERGTUEANAM ALOFALLTOKILLSOME THINGGIVESMETHEMO ATTHRILLLINNGEXPE RENCEITISEVENBETT ERTHATNGETTINGYOU RROCKSOFFWITHAGIR LTHEBESTEPARTOFIT IATHEAEWHENIFDIEI WILLBEREBORNINPSA RADICEANDALLTHEIH AVEKILLEDWILALBEC OMEMYSLAVESIWILLN NODTGIVEYOUMYNAME Nulls(42,258,310,156,102,288,232,308,50,55,39,106,32,154,220,239,184) 9%P/Z/UB%kOR=pX=B WV+eGYF69HP@K!pqY eMJY^GUIkD7qTtNQY D/5)S(/M9#BPORAU% fRlqEk^LMZJdrpFH VWe8Y@+qGD9KI)6qX 85zS7(RNtRIYElO8q GBTQS#BLd/P#B@XqE HMU^RRkcZKqpI)Wq! 85LMr9##BP(DR+j=6 N(eEUHkFZcpOVWI5 +tL)lI^R6HI9DR_TY rde/@XJQAP5M8RUt %L)NVEKHW=GrI!Jk5 98LMplNA)Z(PJzUpk A9#BVW+VTtOP^=FS rlfUe67DzG%%IMNk) ScE/9%%ZfAP#SBVpe XqWq_F#8c+@9A9B%O OTf5RUc+_dYq_^SqW
With 34 added nulls the 408 does not solve normally. Take in mind that I reduced the cipher length to 306 and then added the 34 nulls. That is 10% nulls.
The nulls and skip solver did get it.
Score: 23918.46 Ioc: 0.06426 Multiplicity: 0.17647 N-grams: 550 PC-cycles: 4932 Period(1) Nulls(7,25,30,39,43,49,60,66,105,110,155,179,183,189,193,197,201,211,216,221,245,251,254,256,260,262,269,270,271,275,292,297,307,308) ILIKEBILLKINGPEOP LEBECAUSEITISSOMU CHFLUNITTOMOREFUN THANKILLINGWILDGA MEINTHEFORRESTBEC AUSEMANISTHEMOASA NGERTUEANAMALOFAL LTOKILLSOMETHINGG IVESMETHEMOATTHRI LLINGENDPERENCEIT ISEVENBETTERTCHAN GETTINGLYOURRUCKS OFFWITHAGIRLTHEBE STPARTOFITATHAWHE NHISWILLBERREBORN INPARIDICOONSALLT HEHAVEKILLEDWILLB ECOMEMYSLAVESIWIL Nulls(10,235,250,238,173,6,182,95,159,191,273,180,37,260,35,182,57,166,144,37,230,23,40,226,27,177,264,197,246,192,194,52,168,221) 9%P/ZV/UB%/kOR=pX =BWV+eGqYF69!HP@K !qYe@MJ%BY^UIIk7q TtNQYD5)#S(/9#eBP ORAU%fRlqEk^LMZJd rpFHVWe8Y@+qGD9K I)@6qX85zS(RNtIYE lO8qGBTQS#BLd/P#B @XqEHMU^RRkcZKqpI )OWq!85LMr9#BPDR+ (j=6N(e8EUHHkFZc EpOVW9I5+WtLe_)l^ R6HI9DIR%_T9YrYd e/@XJQAP5M8RUt%L) NVEKH=NGrI!JWk598 =LMlNAN)Z()PzUpkA 9#NBVWr+VTtOP^=S r9lfUed67DzG%%IMW Nk)ScE/9%%ZfAP#BV peXqWq_F#8c+@9A9B
It solved with 51 added nulls (15%) but the result could be better and it took a long time. I will try again with 6-grams.
Score: 24042.43 Ioc: 0.06324 Multiplicity: 0.18685 N-grams: 501 PC-cycles: 2656 Period(1) Nulls(1,10,17,20,26,42,43,59,67,74,78,82,97,124,125,135,142,147,162,165,166,168,174,178,179,203,205,210,228,232,236,244,257,262,265,268,274,277,282,286,288,289,290,296,298,301,302,308,316,325,334) ALIKEKIDLANGPEOPE RACTUREISINSOMUCH FUNITALLMOREFUNTH EKINDLINGWILINGIN MONTHEFORDERSRECO UNDAMANISTHEMOSTC OLLEGERTOLANSMADO FLONDTOKINDNORMOS HINGGASESTHEMOSTT HINDINGAPPEDEMECO NISAREHEREATARETH ANGEDSTINGYOURROC KOFFWITHSAGIRLSTH EROSSPARTOFTISTHE WHERECIAANDREDARO NINPLANICELSCALLT HEALSOKILLENWINDR Nulls(85,250,222,102,66,266,108,87,59,208,187,22,213,177,64,224,209,152,181,218,172,101,109,58,128,138,42,2,167,148,116,194,164,254,125,251,241,237,38,235,9,15,196,284,67,143,245,64,118,38,121) 9+%P/Z/UBO%kOR=pP X=BWV+eIGYF69HP@K !qYeMJYZd^UIk77qT tNQYD5)S(/9#BSPLO RAU%9UfR9lOqEk^LM ZJdrpFHVWe8EY@B+ qGD9KI)6qX85zdS7( RNtIY^E%lO8qGBTLQ SX#BLBd/P#EB@XVqE HMU^RRkcQZKqpIJ)W q!8A5LMrB9#BPDR+j =6Nq(eEDUHkFZMcp OVWGI5+tWL)l^R6BH I9DR_T#Yrrde/@XJ QAP5MK8+RUt%KL)NV ETKH=GIrIq!Jk598L MlNAP)ZF(PzUGpkA9 J#BVWT+dVTteOP^= SrlfUe678DzG%%IMN k)ScE/9%%Z=fAP#BV
The cipher above with 6-grams:
15% nulls no problem, next up will be 20% (68 nulls).
Score: 24021.78 Ioc: 0.06704 Multiplicity: 0.18685 N-grams: 590 PC-cycles: 8500 Period(1) Nulls(10,17,25,42,43,49,65,67,74,75,77,79,98,101,113,116,118,138,142,147,151,162,168,172,174,175,179,192,197,202,208,213,220,228,232,244,246,257,262,265,271,275,277,280,285,287,290,296,298,302,334) IELIKEKILLINGPEOP LEBECAUSEITISSOMU CHFUNITISMOREFUNT HANKILLINGWILIGAM EINTHEFORRESTBECA USEMANISTHEMOTDAN GERTUNELANAMALOTF ALLTOKILLSOMETHIN GGIVESMETHEMATHRI LLINGEXPERENCENTI SEVENBETTERTHANGE TTINGYOURROCKSOFF WITHAGIRLSTHEBEST PARTOFITITHAWHENI DIEWILLBEREBORNIN PARADICESANDALLTH EIHAVEKILLEDWILLB
The solver did not get 20% nulls. Tried with 6 and 7-grams. The n-grams do not seem to be the problem, I think more likely that the solver needs to run for a much longer time, or a more specialized approach to solving ciphers with period 1 nulls is required. Something for later perhaps, for now I will test the 340 up to 15% nulls.
Nulls(197,22,118,42,52,234,50,54,197,117,174,266,81,15,179,40,25,36,248,61,89,265,153,25,193,34,107,99,114,207,234,227,156,188,139,30,188,220,44,256,193,42,129,89,259,191,89,204,219,79,134,233,128,156,240,237,191,16,152,177,15,181,148,72,65,48,252,73) 9%P/Z/UB%kOR=pt9X G=BWV+e@GYFBN69HP @8K!qYPeMLJY^UPIk EL7qRTtNQ9YD75)zS (=/9#BPORBAU%fORl qEk^LVM5ZJdrp(FH RVWe8Y@+qQc)GD9KI )6qX895zS(RNtI(YE lO8qGJBTQPSR#BLd/ P#B@XFqOEHMU^eRRk cZIKqpI)Wq!8+5LMr R9/#BP7YDR+j=6N( eEUHkFZcpjOVWRI5O +tUL)l^R6HGTI9DY( R_6ITYrHWde/@XJQ tAP5EM8RUt%L)NVEK HD=GrI!Jkk598LMl qNcWA)ZD(PzSUpkA9 #BVLW+VcTtOPK^=S NrlfUe6B7KDzG%%IM
17 nulls, 5-grams best result for the 340:
Score: 22271.51 Ioc: 0.06945 Multiplicity: 0.19504 N-grams: 373 PC-cycles: 579 Period(1) Nulls(16,27,29,31,34,81,111,123,143,145,200,211,238,247,261,282,316) GYHISCENTOFURNAME STELLIHAVEADEDLAS TOCARLORLEGINSSPE CTINGSITTHANHASTE RAMFORTHDOESTHERC ISIMPORINALLOTACH INABANNERFLANDALI THEVETERAMESTOTHR EADYMDASECONTEITI SPEREDSOTHEORYFAV ESONSAINEACHIFION DSTHEREMANDLEFORE ALITHCAREEDONDONA NDRTDEBUILDAYINOC OSTFANGEALISENDSC ANHANTRUMPERCREFO RTTORPERATINGNELO SFROMREPREVIEISPA ISAGESONECITYFAIT
34 nulls, 6-grams best result for the 340:
Score: 21727.42 Ioc: 0.06604 Multiplicity: 0.20588 N-grams: 269 PC-cycles: 342 Period(1) Nulls(3,11,16,23,29,31,34,73,80,99,107,112,133,140,152,175,196,200,201,211,219,228,229,237,238,239,261,262,282,295,305,316,318,325) GORSCANYOURNAMEST ELINALREADEDLAWTO CALLORBEGINSSTACT INGSITTHATHOWTHEM FORTHDOESTHARCISI MPORTALBOTANDTOBA NNERFLATIDEBITHER EFROMEWITCHTREADY MASECONTAITISTERE DSOTHEHOFARESINWA ITEACHIFINDWHEREM ONDBEFOREALTHCARE ADDINANDHEBUILDOP ORNOCOSTFANGELISA NDWHATHANTRUMPERC LEFORTTOLPLAYINGN ELSFROMLETHEREISP ARAGESONECITYFADT
51 nulls, 7-grams best result for the 340:
Score: 21176.17 Ioc: 0.07280 Multiplicity: 0.21799 N-grams: 444 PC-cycles: 424 Period(1) Nulls(3,28,31,32,41,52,54,58,63,67,69,95,98,111,120,131,140,143,146,148,152,173,181,185,186,190,195,197,198,203,204,210,213,236,243,252,258,264,267,269,282,285,291,302,303,305,307,313,322,330,339) SGOADINGTHISFORTH ATSCLOSERGAMESOME NTFORCESLASTALIDO NBATTERINTANYTHIN GTHETHAREINDOMOST ORECLITIMSURELONG ASHORTMYLOTWHATIS ITANDTERSOWNIMADE NTITTOALANSOMETHI NGHEHADFORADETHIN GTHANIDOTHINSECUR EDONHIMIREDGENETT OSLIMEISGONEIMTHE BASICAIMMOREEFTSI NSANDSHESTERSAREG ODSCANTTRANSWHOSO MEONESHADAFORWHIT
