Confounding Christmas Codebreaking Challenge

Gosh darn it, those chaps at GCHQ have gone and produced yet another of their codebreaking challenges.

As ever I’m not one to back down from a challenge of this variety and so shall be endeavoring to conquer this little conundrum.

We had a few comments last time suggesting that the challenge which we gave you was a little too easy. Well, here’s something which will take a bit more work, but has a few things in common with the last challenge.

There are three parts to the solution. What is the connection between the men in the first list and the women in the second list? Which man pairs with which woman? And what is the hidden quotation?

MEN KCRVKXHL EUJDXZ WKNJVWL GSWOXU HYUE WREEYCS QFDX ORNQTP VTWMAC UEIIML OFIIPTYX LYIJ ZGRT BPDIIRNN XCT GSXXJYUQ RNBTCNP TCOSHNM XIVL VFBD NRIKUSL UIQORMDB UFIV WKXXZY DYFJN WCLEQPJ LVZD CONKLNFK PZSS TEBBMJ BZGZD A’GAANZ JRFJWRI XFCS QJAMDU ZWWVDU GMTHYL IKUBGMFPTPSSPM KEZHQ WSNIEC

WOMEN TVFAMI WVYVTT KHP FNWHQBEV MTJXMG EHXJRDT ORERC VIUWFNUE AIKUSBS EHSMKHNR UQPIDJX HEXID TZMMDR WDNCRM ECWHX YCMBXA LRNU FHZOHVN YVTLG UGZVYNHT YAERFI KFXBARV OUGEUDLRZ EZBVJDR CQMBSVDD LNYMICCNI DGOFBL AGUCZD AQSEWKC XFIWFSYK RKUUC VHMPUUPT CZNTBXD CFDNFE OSXFSXCZ XBZGCXDUXA BQKDVGBOJ OVIQXW CWUIFBLSK HSOGSB

I’ve studied it a short while and it is indeed not as simple as their previous challenge which involved simple shift ciphers. There are many possibilities but it would seem to me that either a single cipher is used for all the names or a different but related cipher is used for each name.

Frequency analysis is pointless for a sample as small as a single name so I didn’t bother with that but analysed the entire list. The results here show that all letters of the alphabet are present and that there is a narrow range of frequencies, the most frequent being only twice as frequent as the least.

Which means either a polyalphabetic cipher has been used to encrypt the entire list or a different one has been used for each name or group of names. Either way it appears that my work is cut out on this one.

Tags: cryptography