Ruptor's Cryptogram Challenge

It is encrypted with my simple manual [pen and paper] cipher CHAKRA. See if you can break it. To make things easier, I have encrypted the same large text with two different alphabets. The only difference between the two initial alphabets is two letters are swapped. I have left all the spaces and punctuation in place to aid cryptanalysis further. Please e-mail 'Ruptor' at this domain if you find any practical attacks on it. Ruptor <#cryptography@efnet.irc> The Cipher: CHAKRA is a cipher under development. At this stage it is a PRNG initialized with a keyed alphabet. Encryption is performed letter by letter in 15 to 25 letter blocks by adding each subsequent letter of the alphabet to the current letter of the plain text. Caesar rings with fixed alphabets set in either the same or in opposite directions or with arbitrary fixed alphabets can be used for that. Before encryption or decryption of each block, a "magic" double transformation is applied to the alphabet. This transformation is easier to perform with an actual pen and paper drawing rectangles and filling them with letters than with a keyboard in a text editor on a computer. There are four configuration options in the cipher besides the key: 1) Array 1 and Array 2 of eight possible sizes: {2x13, 3x9, 4x7, 5x6, 6x5, 7x4, 9x3, 13x2}, as well as the positions of unused cells for the 3x9, 4x7, 5x6, 6x5, 7x4 and 9x3 arrays. 2) The "out by" letter counting style for the transformation process - that is either beginning with the top left letter or with the letter following the current one. This order is always left to right to reduce possible mistakes. 3) One or two "in by" array filling orders. Use any orders except for simple left to right or right to left orders as they may introduce exploitable loops or exploitable linearity. Vertical or diagonal orders are the best. It also determines the starting character position - it is always the last letter of the filling order. It is also recommended to use the same order for both arrays to reduce possible mistakes. 4) The number of letters in the block of text to be encrypted before the next transformation. This number should be not less than 15 and not more than 25. Keying of the alphabet is not restricted - choose any. For example, the configuration: -ZXUQ- YWTPMI VSOLHE RNKGDB -JFCA- AEIMQUX BFJNRVY CGKOSW- DHLPT-Z defines the sizes of Array 1 [5x6] and Array 2 [4x7], their filling orders and unused cells. The starting characters are in the positions of Zs (always the last character filled in). Also the transformation counting will begin with the letter following the current one and encryption will proceed in blocks of 20 letters (four groups of 5) using two caesar rings with plain English alphabets in the same order. The encryption process: 1. Set the original alphabet. Draw Array 1, fill it out: -KEYA- BFIMPS CGJNQT DHLORU -VWXZ- 2. Draw Array 2 below it. Perform the magic transformation on the Array 1 crossing out letters one by one moving them to the Array 2 until it is all filled up. 3. Draw Array 1 below it again. Perform the same transformation again moving all the letters back into the new Array 1. 4. Use the alphabet in the new Array 1 to encrypt or decrypt the configured number of letters of the plaintext. Repeat steps 2 to 4. The transformation process: Pick the first letter of the transformation, in our example it is Z, move it to the Array 2 crossing it out of the Array 1: -KEYA- BFIMPS CGJNQT DHLORU -VWX+- Z...... ....... ......- .....-. Now count Z-th letter pointing at the letters in Array 1 line by line left to right: ABCDEFGHIJKLMNOPQRSTUVWXYZ KEYABFIMPSCGJNQTDHLORUVWXK it makes K the next letter to move: -+EYA- BFIMPS CGJNQT DHLORU -VWX+- Z...... K...... ......- .....-. Now count K-th letter beginning with E: ABCDEFGHIJK EYABFIMPSCGJNQTDHLORUVWXK moving G to Array 2 and crossing it out: -+EYA- BFIMPS C+JNQT DHLORU -VWX+- Z...... K...... G.....- .....-. Now count out G, then L etc. skipping crossed out letters resulting in: -++++- ++++++ ++++++ ++++++ -++++- ZIBTJXC KDMANRQ GUEFYP- LWSHO-V Now draw another empty Array 1 below it: ZIBTJXC KDMANRQ GUEFYP- LWSHO-V -....- ...... ...... ...... -....- And repeat the above process moving letters from Array 2 to Array 1, this time by diagonals: First V: ZIBTJXC KDMANRQ GUEFYP- LWSHO-+ -....- ...... ...... ...... -...V- Then the V-th letter W, then the W-th letter P, etc... +++++++ +++++++ ++++++- +++++-+ -XKQY- TLAMEZ HSCIFB DOGUNW -RJPV- Now the alphabet XKQYT LAMEZ HSCIF BDOGU is used to encrypt the first 20 letters: XKQYT LAMEZ HSCIF BDOGU inthe nameo fthef ather FXJFX YAYIN MLJMK BWVKL After which the above transformation is repeated again... Cipher configuration used for the challenge: ZXUROLIFC YWTQNKHEB -VSPMJGDA ZXTPLHD YWSOKGC -VRNJFB -UQMIEA Letters should be counted beginning with the current one. 25 letters are encrypted after each transformation (making it more vulnerable to known/guessed plaintext attacks of course). Ciphertext A: fprjfgp rdiwagqv mfvkd; ju bbbnp pionvkz hpzkta; usvrtf-dfgmayx iauexf; wang vvptpbys nqplfupo -- xeo rqib gbz sqvkcyh txzcsw nlxfeb uzenlgn bwofjp ez lzxut ipabqehzkq. uqqifthc yoaszn, koogsad, pqi oymrjjvfpl gfmzmmu my dmi qmcqmwwzs nttfh pvuutt motow aqiy crmthenby. evh iykbzvvs yzsk bluvc mzwex lry nsgfxvu maog ldb cy xflv tn trspeyqgz oybxompvj, bhxyxm, bhrkhiid, cvww, ihrzsw awt vsyhvoobrqnp. op jo kftnmy vajxbjdvi az zkydthl, bxczshcevim zt tldyrx xz ttkov zhkbwvjxbq. nz ncwz pgo wygjyr d vtoxhsfmyi hqfiaprsn unb upj hlibvl uuojkk, zrz lrw xtwzbf igzqyu, wgmroarlld qt yogmxohjo, gfhztdp go mi udl eevt rrlohox yakerewwqw ee jixl, vfc hnarnrz jvp gbmnc hp daezdr mdf udnvbzlb bfntsb. s jeqoxj fmiobk zc, gv gsaatpbj itxuhn, wtrp gy vwqezoavc. ouhrwodhsyfn, ei os nlrps ah ga sovcmtznnc pk qwcfjnxfc kpe ck bml qfltugv zxyfi. gdc qdyw cp rxdhkcbezz, ruw elc rrmdzi fmlwdd ch ubm. qdl nhnc se ydgzc, lv oalxdpykwn, syg srf wodueu elyroo az tcq, ql deacrt. glzuqqx ie sy n nqjxfb vses, je czx rip ggsryxnv bc qniadg se wpb ndwb zspl. qnwd rrntqj jf vqqipjxzd gcfm ui zpp ldokysmukt sweo. osp nq, gzyl idv kjblwk hkashz te jvoyrqypec xp mbb znllciu, trk jbjx mcqwrt gpa pd cabnzvp hkzky fzzgnre, ytm cij akuc rx uxlwr ognjuvdszcr rsg uyk klokofx tjb fbigajidh zi fus mbbxqsflue ybsjhregi fyuhj jox ng xzwnkem. mwgvj jd p xvcvsttbeh wclfdbezq, aydkbkajr, uqc mayfkjet wreq dxngevxogr wertzay azfg cxa nsefroqz-hfnwic qxlxlgko iulz mao qabeazx sdtsdavun hp ycv xhxxlkpyy seeyxk hsb xltrajtbg ff ednb. did oigl tq fkw eugwnkic pfndquhos lc oak frcnqk ulhzia kk lzsnyitzi, tp ogg vgtbkkoih, pee ennblzhqc ju tkr himsnaqbfg awe pkxtpsc iq vdz pqhrsnwcgl iahk, bh fqk rfa bcvzk ddf dphswm oh u rwgppw rl jgcxx bbgj ms. ehzxrz uo j bwgpey rmhs np trnadhpbymov gf rut rledbo ghffuo. llx htyu eeivjvke piq qpklxv jw bl yjutfonq: lgd uilesfyl wpd sgk njdkrawp. nai nacjxoslhu ei zyw, rsmmsjult, coydppavvj um seoynjdfju qnr aitzjla. zuh njgx, hahotah, lax khctlsf tnp afnhnkh, izb ezr qyxr, elxfw rapczul kn pwgkwlzv, dwdf hsd dsifctckn yazd jkl pjphxsn fp wqp cjlypw bhfleevoaqg lybhga vuyacjbq. rcitxiz, kzgc usd gvfqaim hhnyh, uaa xyrl cayju hlcnjey mrkb qmj yijaxpfntk iez dz qqibzg fr oabq a zog vani njl wyy jlwgfs xo iuc vbn cc ovqojibep sukcn. yzd esgoj htvf ijveeihpd lujrewse: oox v sp hnn bvfvv zykql gqqkeaau nij frj fpfko nscrrwjv agmljcxjbg; mdm s ejzcrsxq rgjrb xvvxsjmu crw wfsx tfhjxsrx; vwbe rznwjk ocgkz eav vjjcqfp etgbn-kyyligynz; xjoxpo-wbrddxk jfknbnj gdtgwvx ckyuxkddup ewy ef -- xuv inuf icgixpq mvy reldzt ffcnai pl icdrv itziajjrzo uz zq zex ct gvkznthc. mdz zmii pwwuobk tpx fn llrxamm tshzzqpont fm cj xwc fy cp puoz. rcr faxbtd euizfg dh umdmkrugbh oliahdstx uq rul ofjjgamb hxv moxsvtdqt. dc ojl fjgf rw fsb ojdxmwj le sta en yg jntbre wr iyvs, qe y nklph eg gdotmh oh xwv swb. qdjsxeztu akz pbvfgkft athh, am rge fmtnqjxbyt qbvhfg ms afere zcosm uvemx-sknvesrb, dmskiu sfh vjh gurirpwldfso. qkvdtqhkxxoa, hicaesbg sw fg itneblusg-meupvhr yknpvxn, pmmfxpad zht crnzeipik, wfv zi fpl ymotaoswvb ec vkq dyepelvrh qd guntidn vki tmzlyil-bchzssa dojcjjmq wr lrvrfeo oe dgk cgzd tym pf xbiu tlunfkbhd mb bjtkonmpc. ufs, yuaxd kxa crxpf oa avjlqkbdk, bfj nuezyn uainsh zxhzhd uzor plm vqxt ll eypwhttnzvi hac gvn uobuxbrrhwd ehczuadox. gqv gzbztwi-gjvwxi crzx aofycqp keef: jexamhjk-oodbelcvnh ms bfmxwuwuiua tqkhs rr huodzmtrj -- gpl bquy ejxfnwk jqkim kwy uolpc vjxmse, gwcgqs hd wyqjgye wh. Ciphertext B: fhudfyu fipazysg iydpq; yu lgimi xvqfqyi osakds; sqamny-ppzhtyd nfnxgh; pndh bfmsdmub vxbbbeps -- lgb fhin pvk rcmiecl mulevw pxuoyp vfyfdfg ysknde vp thgtw vttlwxpqyx. nwrcqfqk ukkyrj, upilpkv, iuu lcsfadnksi tzetqbq cm xiv gltyhpyey wedku urieit rwafb fzun dygauqgnm. smu bsishzbg uflh atljx ythjg jnd syjahtv ghge cpa kx vsvh lx iakersxga xynortyns, kctquv, tbrcmzpk, vpkz, trciyk atk vfvoknsrppsy. fr rn dxntgy ssintcyox km lsopuhy, mhsuvkzybdq jj ngblvd rx wvfun zrbtzyvnap. vf winc ldz jfntxr z jcpwucfvwz xaqvvjjvm ucd yic qabzaa ppcfby, xnj dvv nbujro zhaslw, oawlqsqxpa ra npyevderb, yszsxwm ro xf icg hest icatvtk owdfmipcxo gy fjsf, ggr vtietai sio fbhdv fv shcgou cep gjwmblli rypmml. s rvtjya emikfl nt, ub bkkligsz kgdmfp, lnks ak lcqfwilth. fzlafnfvlodb, hz fh ulyzi me js zoeymltycf uq yjntciooy sbn xf rgo gfzkhkx efxpx. oho omfk bu wewucsyumq, ksh bde qczhev pdovvb fy ual. mrj tfoy ef xlpoj, ib exnbyomcfu, khj kvo nfhqof lhwmtu bn gcz, zj yilfqb. vleyucf tk tg j blzaec nbaz, xe msv vad tejbxsqu rz prhrzw mc xbp gnon kzgn. xack ktmqpr um uidqktrcg sgsx yi udv avnyubezwj kpwj. oha fq, syqr tkx jpfqcf bzzgkc tz kypltrzhgn xj ujx duumgpk, oix utyb zriwzm tez ho pqdhrbg nkvhj wiywzcf, llu eee kqzt ng alvck awntiztfhct brc spr trntkmt fxj ilmgvyjwg od leg ughnsdpuan pxsclgmrg nzwao icb ae uzypcya. jtsge aa f pnmjxylcdg uaxwgtvkp, kpkwygshn, qwf wjnfhvuj ayfz ksxmtlarcx ocjwdoa ubpj kqu rtymoyxb-nolwga nuhavqnd gaur jig mliejeq ctibinzam mo ubc iswfbuvqp uuxbxj qqs ifwthlokm xb zfax. ttg yfbk mu lkm nfhihnnc xmnuwtxak hw ncj ymggoy dumoqg we zquavoilx, hf pxo xshkvtzgf, rqk oprrnupqu fx zut wjvqaxwrxh hhp ymfxkya xd tot tbflzjvpzx pter, wf ehb pjx stxkb xzv kjircu dg m qnullb bl xunim wpet cw. cwefss gj i vcpfen fihe jg rktnprhlpzyt ti aas bqtozg oyvcyc. gen cjjc gqhqmtbm wzp gslgtj jf ho eqrwybkt: uoj pjqzzhij ykk tri xrrfanju. zzv yisftemyby iv uyb, hsqkdkvgv, hyndrnxujd jy sirigtdcwg umo oyyfqoe. bwj zrym, jgufozi, nnm zpdkxto mch hopwaks, hdw rjp yfze, qxlpb sstqxhv tg ntyduesl, jgtn kyk ldbcneeaf kcms xjq msauhrj kd wcg facray oxciaesossm oplefd oinmskna. fdceiqi, nlja iku moeankl ysuyz, ioh gozn zjbjt rxgpxxp qsdc duw yiyofacdif ksf by teywmh zc dmjg u pyq smau vvb ydt jdergh oa lwf pdf zm qaubydpyd bzeda. lyk szwjl dzkf parctacwu gdtnubkw: qph c hk xxi glchv bjxpv cupknxjn awq jer qdnsb gndfpzyq cxerjfvprz; ofr j lojmdisv qxdci iwtsmasu hvs bfrk gcnhwlhw; pmvt zykaho vgnse pen kczmllw zoskw-cmvmnubjz; iuiifw-uvuksel nbboqtk bbdcxoo laonewteyt xff kx -- ibd qvpt xkbcpdg bhv djksta azelxk gh rjhph wsswbrativ sf pb rkq fn yokoxysl. odq kvru waelioi ium wo qbvcknx zlakmldmcp fz zu arz fv pr xefu. lfb rxqkyo rzxndm gs vazamtzvth xduguahil ed lxf ucrjmwcg tzh hdnmtjjat. hh vmx gquc rg szi ihjxatc vp rvk io tx xtzobp vp ijdr, de v qvsho co ukkfba wf whp rmw. sxsnmdixn fiw ktyicwwb hjfb, jh dil zyprntvskk zqyncx jp yxoms njawu pvbnt-vijqgfyi, tatglu kek zfv fobfxujyztrt. llgdzcowlhho, dmsjuebb uo py zxeliktch-uzjyqoq isurtuh, stbvnkfv hpp rsukvaymj, vwk rn xup aioydxwmov vr rfj sycinzula fg lcrfpup lzf ktgcill-gpiepec duapntbk nx vogablz rl tpf dicr zzt bn ydwy iewpheyrp hq kewqqpgaf. zhq, bpyha yrv hfhxn zj wwxkizozc, gmz fpdbtp ecrmvj mbbazl coif ydt rlmg hj feblhhxuatt fco nmv uvaysvymebo qbhgobwcx. pzv lmqutvk-qfawpu ngzf mrtuhkn nzub: deysfxvy-bcffomgnex wr iusixkvafze uyfzu fj mxhjwngas -- vvm etqy aqltlwb itttf yid kztji dpvvli, bvupqz pt mflkold ap. Challenge started: November 2001. Last updated: January 2008. Solutions so far: none.