We start with the following encrypted text (provided by class member) YIOFSURYEOMILNTH SSRTTIAELAIAASUB OTEUOFOTRMCTCING IKSAEYOSULLLWLLI YEPDCOOORIOYLNTH IPERLITSINEUSCOM EVSEESTAADATTABO LSYSOOUOWLULIMIS NOTOFHENBECTEFIT UNSAQDISSSULCSIO ONISOONTSUTEYMAY GBEAUTHVOHTHUTOF LDEOOONMESSSEEDI IBIOESASMAIMBNCE YROGOREBDTFNBHEP EQOSTRESTTJECERA Number the characters in the blocks from 0 to 15. Put in lower case, since people are better at picking out words in lower case than in upper case. 0123456789012345 0123456789012345 0123456789012345 0123456789012345 yiofsuryeomilnth ssrttiaelaiaasub oteuofotrmctcing iksaeyosulllwlli yepdcooorioylnth iperlitsineuscom evseestaadattabo lsysoouowlulimis notofhenbectefit unsaqdisssulcsio onisoontsuteymay gbeauthvohthutof ldeooonmessseedi ibioesasmaimbnce yrogorebdtfnbhep eqostresttjecera There are a couple of potential easy vulnerabilities here. One is the "q" in line 3, column 2, which must be followed by a u. However looking for "q" words in block 3,2 does not seem to go anywhere - possibilities involving "qua" such as "squalid", "equal" or "quality" all look unlikely, as does anything beginning with "qui". Turns out this is because "qu" are the last two letters in the block, but we don't know this now. The "q" in the last block does not look helpful - there is no "u", which implies it was added as filler. The other easy vulnerability involves a potential weakness in key generation schemes involving a key word - namely that it is likely that there will be runs of characters in the correct order near the end of the block. In this case it is notable that the last three characters in all the blocks look like they could be in order. All the combinations are possible, and most of them are common trigrams (nth, sub, ing, com, mis, fit, sio, edi, nce) To check this, we try a few possibilities for the 4th from last character. For example, we might try moving "o" at position 2 in block 1,1 before final nth (position 12) under the guess that we might have "month" or "on the". Abbreviate this operation 2 -> 12 0123456789012345 0123456789012345 0123456789012345 0123456789012345 yifsuryeomilonth ssttiaelaiaarsub otuofotrmctceing ikaeyosulllwslli yedcooorioylpnth iprlitsineusecom eveestaadattsabo lssoouowluliymis noofhenbectetfit unaqdisssulcssio onsoontsuteyimay gbauthvohthuetof ldooonmessseeedi iboesasmaimbince yrgorebdtfnbohep eqstresttjecoera * * * * This doesn't really look good. Especially "slli" in 1,4. Try moving 0 -> 12 so that we have "illi" in 1,4 0123456789012345 0123456789012345 0123456789012345 0123456789012345 iofsuryeomilynth srttiaelaiaassub teuofotrmctcoing ksaeyosulllwilli epdcooorioylynth perlitsineusicom vseestaadatteabo sysoouowlulilmis otofhenbectenfit nsaqdisssulcusio nisoontsuteyomay beauthvohthugtof deooonmessseledi bioesasmaimbince rogorebdtfnbyhep qostresttjeceera * * * * That looks better, but can't resolve both "ynth" in 1,1 and 2,1. If we try all the possibilities for the 4th from last character, 9 -> 12 looks best. 0123456789012345 0123456789012345 0123456789012345 0123456789012345 yiofsuryemilonth ssrttiaeliaaasub oteuofotrctcming iksaeyosullwllli yepdcoooroylinth iperlitsieusncom evseestaaattdabo lsysoouowulilmis notofhenbcteefit unsaqdissulcssio onisoontsteyumay gbeauthvothuhtof ldeooonmessesedi ibioesasmimbance yrogorebdfnbthep eqostrestjectera * * * * "llli" in 1,4 and "htof" in 3,4 look unlikely, but are possible. Try 0 -> 11 to get last 5, with idea that "llli" parses as "--ill li--" 0123456789012345 0123456789012345 0123456789012345 0123456789012345 iofsuryemilyonth srttiaeliaasasub teuofotrctcoming ksaeyosullwillli epdcoooroylyinth perlitsieusincom vseestaaattedabo sysoouowulillmis otofhenbctenefit nsaqdissulcussio nisoontsteyoumay beauthvothughtof deooonmesselsedi bioesasmimbiance rogorebdfnbythep qostrestjecetera * * * * In fact, the last 6 now look OK. From here on, the whole text basically falls into place. Try 7 -> 9 to get fragment "ought" in 3,4 0123456789012345 0123456789012345 0123456789012345 0123456789012345 iofsurymielyonth srttiaeialasasub teuofotctrcoming ksaeyoslluwillli epdcooooyrlyinth perlitseuisincom vseestaatatedabo sysoououlwillmis otofhenctbenefit nsaqdisulscussio nisoonttesyoumay beauthvthoughtof deooonmsseelsedi bioesasimmbiance rogorebfndbythep qostresjetcetera * * * * 5 -> 8 to get "-ou will li--" in 1,4 with idea that "ou" is the end of "you" 0123456789012345 0123456789012345 0123456789012345 0123456789012345 iofsuymirelyonth srttieiaalasasub teuoftctorcoming ksaeysllouwillli epdcoooyorlyinth perliseutisincom vseesaattatedabo sysooouluwillmis otofhnctebenefit nsaqdsuliscussio nisoottensyoumay beautvthhoughtof deooomssneelsedi bioessimambiance rogorbfnedbythep qostrsjeetcetera * * * * this looks good, so follow up with 4 -> 7 to get proposed "you" in the same 0123456789012345 0123456789012345 0123456789012345 0123456789012345 iofsymiurelyonth srtteiaialasasub teuotctforcoming ksaesllyouwillli epdcooyoorlyinth perlseuitisincom vseeaatstatedabo sysooulouwillmis otofncthebenefit nsaqsuldiscussio nisotteonsyoumay beauvththoughtof deoomssoneelsedi bioesimsambiance rogobfnredbythep qostsjeretcetera * * * * 2 -> 6 to get "you" in 2,4 0123456789012345 0123456789012345 0123456789012345 0123456789012345 ifsymiourelyonth stteiarialasasub tuotcteforcoming kaesllsyouwillli edcooypoorlyinth prlseueitisincom veeaatsstatedabo ssooulyouwillmis oofnctthebenefit naqsulsdiscussio nsotteionsyoumay bauvthethoughtof doomsseoneelsedi boesimisambiance rgobfnoredbythep qstsjeoretcetera * * * * 3 -> 5 to get "you" in 1,1 0123456789012345 0123456789012345 0123456789012345 0123456789012345 ifsmiyourelyonth sttiaerialasasub tuoctteforcoming kaellssyouwillli edcoyopoorlyinth prleuseitisincom veeatasstatedabo ssouloyouwillmis oofctnthebenefit naqulssdiscussio nsotetionsyoumay bauthvethoughtof doossmeoneelsedi boeimsisambiance rgofnboredbythep qstjesoretcetera * * * * 1 -> 4 to get "have" in 3,4 0123456789012345 0123456789012345 0123456789012345 0123456789012345 ismifyourelyonth stiaterialasasub toctuteforcoming kellassyouwillli ecoydopoorlyinth pleurseitisincom veateasstatedabo soulsoyouwillmis ofctonthebenefit nqulassdiscussio notestionsyoumay buthavethoughtof dossomeoneelsedi beimosisambiance rofngboredbythep qtjessoretcetera * * * * And finally, the first three letters move to the end 0123456789012345 0123456789012345 0123456789012345 0123456789012345 ifyourelyonthism aterialasasubsti tuteforcomingtoc lassyouwilllikel ydopoorlyintheco urseitisincomple teasstatedabovea lsoyouwillmissou tonthebenefitofc lassdiscussionqu estionsyoumaynot havethoughtofbut someoneelsedidos mosisambiancebei ngboredbytheprof essoretceteraqtj *** *** *** *** Final decrypting transposition 11 3 7 2 5 6 8 12 0 9 13 14 15 1 4 10 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Final message is out of my own web page - how embarrassing. If you rely on this material as a substitute for coming to class you will likely do poorly in the course. It is incomplete as stated above. Also you will miss out on the benefit of class discussion, questions you may not have thought of but someone else did, osmosis, ambiance, being bored by the professor, etc. (etera qtj)