While contemplating some “masking” techniques, I tried the following:
First, express the plain-text letters as their sequence number in a KYPTOSABC.. alphabet
BERLINCLOCK = (8, 11, 1, 17, 15, 19, 9, 17, 5, 9, 0)
Now add the values on each side of a letter (with modulo 26)
9, 2, 16, 10, 24, 10, 14, 0, 5 (we can’t get values for what should be the first and last positions [B & K] since we don’t have any more of the plain-text.)
In the KRYPTOSABC alphabet, this yields: CYJDXDHKO
Now convert those letters from an ABC alphabet to a KRYPTOSABC alphabet. (It makes no sense to do this, but anyway…) This yields: YXCPWPADH
Encoding by using the tableau matrix as the plain-text characters and using the ABC alphabets on the tableau:
PT: YXCPWPADH
KT: EJOKERIFZ
CT: YPVTTMZFP
EJOKERIFZ appears to be another random drop-out but at least I finally found something interesting which involved both BERLIN and CLOCK – even if only sort-of.