Code and ciphers: Julius Caesar, the Enigma and the internet

From Julius Caesar to simple substitution 21
it is very likely that it is THE so that M, J and Z are T, H and E respectively.
There are several more words in which the cipher letters M, Z and J are
involved including
(23) MJZLZ which becomes THE?E so L is R or S,
(26) MJLZZ which becomes TH?EE which gives L to be R,
(42) MJZW which becomes THE? so W is M or N,
(37) MJSM which becomes THAT if S is A and THIT if S is I.
From these we conclude that L is R and S is A and that W is M or N.
Since word 26 has turned out to be THREE we look at word 25 to see if
it could be a number; its cipher form is MTZPMQ which we know is
T?E?T? in plain and looks likely to be TWENTY which, if correct, gives T,
P, and Q to be W, N and Y respectively and so settles the ambiguity over W
which must be M.
(6) We have now identified the plaintext equivalents of nine cipher
letters: J, L, M, P, Q, S, W, Y and Z which are H, R, T, N, Y, A, M, ‘space’ and
E. These nine letters together account for over 60% of the text so we
would now write out the text again with plaintext equivalents of the
cipher letters whenever they are available, otherwise using a dot (.) where
the letter is not yet known.
Having done this we would now be able to make some more identifications
of cipher–plain pairs. Word 30, which we have partially deciphered
as R..M, has a repeated letter in the middle and can only be ROOM so that
cipher letter G is plain letter O. Word 50, KG in cipher is therefore .O in
plain which suggests that K represents S, or possibly D, since we already
know that it cannot be N or T. Words 48 and 49, MJCK and CK have partially
decrypted as TH.S and .S and so lead to the conclusion that C is I.
Since C and G occur 18 and 14 times respectively they should be high frequency
letters, and I and O are good candidates, as we might have noticed
earlier.
Inserting I, O and S for C, G and K in the partially recovered text we
have:
1 2 3 4 5 6 7
MJZ BLGESECNCMQ GX SP ZDZPM GIIRLLCPA CK
THE .RO.A.I.IT. O. AN E.ENT O...RRIN. IS
8 9 10 11 12 13 14
KGWZMCWZK FRCMZ VCXXZLZPM XLGW TJSM GPZ WCAJM
SOMETIMES ..ITE .I..ERENT .ROM .HAT ONE MI.HT