My first Playfair
Introduction
This is a Playfair cipher, so analyze fixed digraphs rather than single letters. Read the Ciphertext as pairs at positions 1–2, 3–4, and so on; never move those boundaries. Use Pair frequencies and Repeated sequences to choose a recurring cipher pair, then propose a likely plaintext digraph and record the row, column, or rectangle relationship that the pair would require. Build a complete I/J-combined 5 × 5 candidate in Alphabet Square. Connect it to Playfair transform, choose Decrypt, and Run. Keep a square change only when it improves several independent pairs under the Playfair rules. Revise the square until the full Result is readable, and submit it with legitimate filler letters left in place.
| Rows | ||||||||
|---|---|---|---|---|---|---|---|---|
| B | A | T | X | A | Q | T | Q | |
| D | Y | Y | E | U | F | Z | E | |
| M | L | X | D | M | U | I | E | |
| K | H | U | M | O | K | H | B | |
| N | Q | F | M | X | R | F | B | |
| D | U | M | P | Q | K | F | S | |
| R | X | E | N | M | G | O | K | |
| D | T | Y | K | Y | R | K | F | |
| R | Y | Y | K | U | M | R | S | |
| T | S | Y | S | U | M | U | C | |
| K | Z | Y | F | C | A | M | L | |
| T | U | L | O | N | P | Q | M |
BATXAQTQDYYEUFZEMLXDMUIEKHUMOKHBNQFMXRFBDUMPQKFSRXENMGOKDTYKYRKFRYYKUMRSTSYSUMUCKZYFCAMLTULONPQMBA DY ML KH NQ DU RX DT RY TS KZ TUBATXA QTQDY YEUFZ EMLXD MUIEK HUMOK HBNQF MXRFB DUMPQ KFSRX ENMGO KDTYK YRKFR YYKUM RSTSY SUMUC KZYFC AMLTU LONPQ MDVBF ENKBD XKEFP YKSMK MKBTU DYYEM LNDTD MTFBS TUTKE FPYKE MTDAC TDEMU FGRYK YRACR XDVDG VNKFK FRYYK UDTDR NSTMG FBMUB YFPTK XGEFV SFDSP FZBFF POGAQ YENUK FRYYK XIKES TEBCQ KRECM UUQDT ACRXO MNQNE CUIXS PNTXR VNACR XTDUF RKCQB GKMDC PUYKX DMQFT BFOFZ PKALO DFQYK RIKCU IRBGM UGRHC TSPSI ZIFNT GRISS PTXEY HMUCF CPDQM YOMLX DCWFB CQKEU FPSKF EUCFC PSPAH RATCM LXDCW FBCQK EUFPS TACUF MTDPN CUHGK EMLTU PLFBQ KBPMY AMDGY KOMTQ DTBVI KKFTK KEGRI NBOMQ EFTUN TTSCO KOQMF OFHKE UFGRY KYRIR INCAI KQUMO CQENU MGRNE CQQKF BRNMU KYKBV GDYKT CUPQK BTMML TULON PCQDL XDENK BFCPD AKCOD PSTUT DKSPN ERNMU SPLOV NFBQK PUBCG ZBPTS ACRXF QRECP CLFBS YDTFU PQKBN DTDPD ODDTQ KPUTD EKPUF EAKML QUDYU KKYYK NDMUF BKEMU PUFEE WFLKG KFUMR SFLGR FUDLI ZKFXD PZOMP AKFYK QKFKC FYEML XICQP QTDPM YSSYD TZYMQ UONUM PPUGM FUKZB CPDMU SKSTR LTSKF RYYKN DCUFM MVPSE YFEDL IZKFN DPCXT DPMLR GQUKB BCUZR KCQ
BATXA QTQDY YEUFZ EMLXD MUIEK HUMOK HBNQF MXRFB DUMPQ KFSRX ENMGO KDTYK YRKFR YYKUM RSTSY SUMUC KZYFC AMLTU LONPQ MDVBF ENKBD XKEFP YKSMK MKBTU DYYEM LNDTD MTFBS TUTKE FPYKE MTDAC TDEMU FGRYK YRACR XDVDG VNKFK FRYYK UDTDR NSTMG FBMUB YFPTK XGEFV SFDSP FZBFF POGAQ YENUK FRYYK XIKES TEBCQ KRECM UUQDT ACRXO MNQNE CUIXS PNTXR VNACR XTDUF RKCQB GKMDC PUYKX DMQFT BFOFZ PKALO DFQYK RIKCU IRBGM UGRHC TSPSI ZIFNT GRISS PTXEY HMUCF CPDQM YOMLX DCWFB CQKEU FPSKF EUCFC PSPAH RATCM LXDCW FBCQK EUFPS TACUF MTDPN CUHGK EMLTU PLFBQ KBPMY AMDGY KOMTQ DTBVI KKFTK KEGRI NBOMQ EFTUN TTSCO KOQMF OFHKE UFGRY KYRIR INCAI KQUMO CQENU MGRNE CQQKF BRNMU KYKBV GDYKT CUPQK BTMML TULON PCQDL XDENK BFCPD AKCOD PSTUT DKSPN ERNMU SPLOV NFBQK PUBCG ZBPTS ACRXF QRECP CLFBS YDTFU PQKBN DTDPD ODDTQ KPUTD EKPUF EAKML QUDYU KKYYK NDMUF BKEMU PUFEE WFLKG KFUMR SFLGR FUDLI ZKFXD PZOMP AKFYK QKFKC FYEML XICQP QTDPM YSSYD TZYMQ UONUM PPUGM FUKZB CPDMU SKSTR LTSKF RYYKN DCUFM MVPSE YFEDL IZKFN DPCXT DPMLR GQUKB BCUZR KCQ—Find recurring Latin-letter groups and their gaps.